Chronotherapeutic Drug Delivery System of Flurbiprofen

“DESIGN AND EVALUATION OF CHRONOTHERAPEUTIC DRUG DELIVERY SYSTEM OF FLURBIPROFEN”

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Mr. VINAY KUMAR.K.V. B. Pharm., Reg. No.09PU334 Dissertation Submitted to the Rajiv Gandhi University of Health Sciences, Karnataka, Bangalore In partial fulfillment of the requirements for the degree of MASTER OF PHARMACY IN PHARMACEUTICS

Under the guidance of Dr. T. SIVAKUMAR M. Pharm., Ph.D.

Department of Pharmaceutics Bharathi College of Pharmacy Bharathinagara 2011

RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES, KARNATAKA, BANGALORE

DECLARATION BY THE CANDIDATE I hereby declare that the matter embodied in the dissertation entitled hereby declare that the matter embodied in the dissertation entitled “DESIGN AND EVALUATION OF CHRONOTHERAPEUTIC DRUG DELIVERY SYSTEM OF FLURBIPROFEN” is a bonafide and genuine

research

work

carried

out

by

me

under

the

guidance

of

Dr. T. Sivakumar M. Pharm., Ph.D., Department of Pharmaceutics, Bharathi College of Pharmacy, Bharathinagara. The work embodied in this thesis is original and has not been submitted the basis for the award of degree, diploma, associate ship (or) fellowship of any other university (or) institution.

Date: Place: Bharathinagara

Mr. VINAY KUMAR.K.V. B. Pharm.,

BHARATHI COLLEGE OF PHARMACY BHARATHI NAGARA-571422

CERTIFICATE BY THE GUIDE This is to certify that the dissertation entitled “DESIGN AND EVALUATION OF CHRONOTHERAPEUTIC DRUG DELIVERY SYSTEM OF FLURBIPROFEN”

is a bonafide research work carried out by

Mr. VINAY KUMAR.K.V. submitted in partial fulfillment for the award of the degree of “Master of Pharmacy” in pharmaceutics by the Rajiv Gandhi University of health sciences, Karnataka, Bangalore.

Date: Place: Bharathinagara

Dr. T. SIVAKUMAR M. Pharm., Ph. D. Professor and HOD, Department of Pharmaceutics, Bharathi College of Pharmacy, Bharathinagara – 571422

BHARATHI COLLEGE OF PHARMACY BHARATHI NAGARA-571422

ENDORSEMENT BY THE HEAD OF THE DEPARTMENT This is to certify that the dissertation entitled “DESIGN AND EVALUATION OF CHRONOTHERAPEUTIC DRUG DELIVERY SYSTEM OF FLURBIPROFEN”

is a bonafide research work carried out by

Mr. VINAY KUMAR.K.V. submitted in partial fulfillment for the award of the degree of “Master of Pharmacy” in Pharmaceutics by the Rajiv Gandhi University of Health Sciences, Bangalore, Karnataka. This work was carried out by him in the library and laboratories of Bharathi College of Pharmacy, under the guidance of Dr. T. Sivakumar M.Pharm., Ph.D. Department of Pharmaceutics, Bharathi College of Pharmacy,

Bharathinagara.

Date: Place: Bharathinagara

Dr. T. SIVAKUMAR M. Pharm., Ph. D. Professor and HOD, Department of Pharmaceutic Bharathi College of Pharmacy, Bharathinagara – 571422

BHARATHI COLLEGE OF PHARMACY BHARATHI NAGARA-571422

ENDORSEMENT BY THE PRINCIPAL / HEAD OF THE INSTITUTION This is to certify that the dissertation entitled “DESIGN AND EVALUATION OF CHRONOTHERAPEUTIC DRUG DELIVERY SYSTEM OF FLURBIPROFEN”

is a bonafide research work carried out by

Mr. VINAY KUAMR.K.V. submitted in partial fulfillment for the award of the degree of “Master of Pharmacy” in Pharmaceutics by the Rajiv Gandhi University of Health Sciences, Karnataka, Bangalore. This work was carried out by him in the library and laboratories of Bharathi College of Pharmacy, under the guidance of Dr. T. Sivakumar M.Pharm., Ph.D. Department of Pharmaceutics, Bharathi College of Pharmacy,

Bharathinagara.

Date: Place: Bharathinagara

Dr. T. TAMIZH MANI M. Pharm., Ph.D. Principal, Bharathi College of Pharmacy, Bharathinagara – 571422.

COPYRIGHT

DECLARATION BY THE CANDIDATE

I hereby declare that the Rajiv Gandhi University of Health Sciences, Karnataka shall have the rights to preserve, use and disseminate this dissertation / thesis in print or electronic format for academic / research purpose.

Date: Place: Bharathinagara

Mr. VINAY KUMAR.K.V. B.Pharm.,

© Rajiv Gandhi University of Health Sciences, Karnataka.

ACKNOWLEDGEMENT I am thankful to the Almighty for blessing in successful completion of this dissertation. Many Thanks to Almighty God (Lord Hanuman, Lord Shiva, Lord

Kukke-Subramanyaswamy,

Lord

Lakshmi,

Lord

Saraswathi,

Lord

Ganapathi) for it he who began this work in me and carried it to completion. It is He who has blesses me with the people whose names I feel privileged to mention here. This M’Pharm makes me to suffer a lot (mentally,economically,emotionally) because of one trustless friendship,because of that I lost trust in my family in all the aspects,till today i suffers like anything and its difficult to overcome from that,so I pray god to put fullstop for my worries as soon as possible. I primarily thankful to say heartly thanful to my brother in law Mr.Praful Chandra,for his encouragement throughout my M’pharm. I consider it as a great privilege to express my heartfelt gratitude and sincere thanks to my esteemed guide Dr. T .Sivakumar, Professor, Head of department of Pharmaceutics, Bharathi college of pharmacy, Bharathinagara, for his valuable suggestions, encouragement, motivation, guidance and co-operation during my dissertation work. I take this opportunity to express my thanks for Mrs. K. Kavitha, Assistant professors,

Dept.

of

Pharmaceutics,

Bharathi

Bharathinagara, for her support during my project.

College

of

Pharmacy,

I take this opportunity to express my thanks for Mr Ganesh, Assistant professors,

Dept.

of

Pharmaceutics,

Bharathi

College

of

Pharmacy,

Bharathinagara. I taken this opportunity to express my regards to Dr. T. Tamizhmani, Principal, Bharathi College of Pharmacy,Bharathinagara. I am very much grateful to Micro Labs Bangalore, for providing me gift sample of bulk drug for carriying out my project work. I express my deep gratitude to, Mr.Rupesh kumar, Mr.shivkumar, Dr.Siju,

Mr. Jose gnana babu, Mrs. Sowjanya, and the entire staff of Bharathi College of Pharmacy for the valuable guidance during the course of study. “Friend in need are friends indeed”, I thank to my dearest friends

Chandrashekar, Challa Chenchi Reddy, Vinodkumar, Nitin, Anil kumar, Chikkanumegowda, Balappa,

Rakshith,

Madhusudhan, KP,

Poornachandra,

Shanthikumar,

Pani,

Arjun,

Umesh,

Kempegowda,

Srimanarayana , Sidhram, Harish, for their support in my life. I specially convey my gratitude to my dearest classmates Pavan, Rajas,

Mangesh, Dipen, Sandeep, Mehaboob, Kiran, Mehul, and my college collegues Shivraj, Selvam, Puneeth, Tanusha, for their timely help, support and memorable company during this course I was specially thankful to Mr.Tatiparthi Nagarjuna Reddy, for supporting me to complete my dissertation work in the mean time. I convey my special thanks to my dearest friend and my senior

Mr.Anil Kumar.S.N, for his valuable guidance and support during my course.

I heartly thankful to my dearest friend Mr.Vijay Kumar.V.N, for supporting me to overcome from such a huge headache in my M’Pharm. I thank specially to Puttamadu, satish, Sreenivas, Anil, Chandru,

Sathish,

Cheluvegowda,

Govinda,

Siddhegowda,

Shivlingegowda,

Doddaiah, Siddhaiah, and all the nonteaching staff for their friendly nature and for their timely help. I thankful to Mr.Nanda, Librarian for helping me a lot during my M.Pharm, by providing necessary books, articles, journals in the mean time. It is my privilege to utilize this golden moment and bow myself to acknowledge my mother Mrs.Sundramma,my father Mr.VeereGowda.K, my sister Mrs.Tanuja Praful Chandra,my brother in law Mr.Praful Chandra, and my grand mother Mrs.Jayamma, for providing me an opportunity to pursue my higher education along with their love and moral support.. At last but not least, I would like to express my thanks to Mr.B.Basavaraju, Working president, Bharathi education trust, and Management of Bharathi College of Pharmacy for providing necessary facilities during my course of study. My Sincere thanks to all

Date: Place: Bharathinagara.

Mr.VINAY KUMAR.K.V B.Pharm,

DEDICATED TO MY APPLE RAHUL.P.HINDWAL

LIST OF ABBREVIATIONS

LIST OF ABBREVIATIONS Abs

: Absorbance

0

: Temperature on Celsius Scale

C

CAP

: Cellulose Acetate Phthalate

Cm

: Centimeter

cm2

: Centimeter square

Cps

: Centipoises

o

: Temperature on Faranide Scale

FDA

: Food and Drug Administration

Gms

: Grams

HPMC

: Hydroxy propyl methyl cellulose

Hrs

: Hours

IP

: Indian Pharmacopoeia

IR

: Infrared

kg/cm2

: Kilogram per centimeter square

L.R.

: Laboratory Grade

Mg

: Milligram

µg/mcg

: Microgram

Min

: Minutes

mm

: Millimetre

NSAID

: Non-steroidal anti-inflammatory drug

Nm

: Nanometre

P.G

: Pharmaceutical Grade

‘R2’

: Regression Coefficient

F

Department Of Pharmaceutics, Bharathi College Of Pharmacy.

LIST OF ABBREVIATIONS

Rpm

: Resolutions per minute

SEM

: Scanning Electron Microscopy

SD

: Standard Deviation

UV

: Ultraviolet

v/v

: Volume/Volume

w/w

: Weight/Weight

% w/v

: Percentage weight by volume

% w/w

: Percentage weight by weight

F1

: Flurbiprofen: Eudragit L-100: Eudragit S-100

F2

: Flurbiprofen: Eudragit L-100: Eudragit S-100

F3

: Flurbiprofen: Eudragit L-100: Eudragit S-100

F4: Flurbiprofen

: Eudragit L-100: Eudragit S-100

F5 : Flurbiprofen

: Eudragit L-100: Eudragit S-100: HPMC (20mg)

F6 : Flurbiprofen

: Eudragit L-100: Eudragit S-100: HPMC (30mg)

F7: Flurbiprofen

: Eudragit L-100: Eudragit S-100: HPMC (40mg)

Department Of Pharmaceutics, Bharathi College Of Pharmacy.

ABSTRACT

ABSTRACT In this study, investigation of an oral colon specific, pulsatile device to achieve time and/or site specific release of Flurbiprofen, based on chrono-pharmaceutical consideration. The basic design consists of an insoluble hard gelatin capsule body filled with eudragit microspheres of Flurbiprofen and sealed with a HPMC plug. The entire device was enteric coated, so that the variability in gastric emptying time can be overcome and a colon-specific release can be achieved. The Flurbiprofen microspheres were prepared by solvent evaporation method with Eudragit L-100 and S-100 (1:2) by varying drug to polymer ratio and evaluated for the particle size, angle of repose, percentage yield, drug content, SEM, IR and in-vitro release study. The cumulative % release for F1, F2, F3 and F4 were found to be 95.91%, 92.06%, 89.17%, and 87.81% at the end of 12th hr. From the obtained result formulation F3 was selected as an optimized formulation for designing pulsatile device. A hydrogel polymer HPMC was used as plugs in different ratios, to maintain a suitable lag period. The entire device was coated with 5% CAP. The formulated pulsatile device was evaluated weight variation, thickness of CAP and in-vitro release study. The in-vitro release study were carried out using pH 1.2 buffer for a period of 2 hrs then 7.4 pH phosphate buffer for a period of 3hrs then 6.8 pH phosphate buffer for a period of 10 hrs. At the end of 15th hrs the drug release was of 75.96 %, 72.01 % and 59.92 % for F5, F6 and F7 respectively. Keywords:

Pulsatile; Colon-specific device: Chronotherapeutics: arthritis; Eudragit

microspheres.

Department of Pharmaceutics, Bharathi College of Pharmacy.

CONTENTS

CONTENTS Chapter No. 1

2

3

Title

Page No.

Introduction

1

1.1 Circadian rhythms and their implications

2

1.2 Chronotherapeutic: therapy in synchrony with biorhythms

4

1.3 Arthritis

4

1.4 Chronopharmaceutics

9

1.5 Pulsatile drug delivery systems

10

1.6 Colon specific drug delivery systems (CSDDS)

15

1.7 Methods for targeting drug into the colon

17

Aims and Objectives

19

2.1 Plan of work

19

Review of literature

21

3.1 Drug profile

26

3.1.1 Flurbiprofen 3.2 Excipient profiles

26 28

3.2.1 Eudragit l 100 and Eudragit s100

28

3.2.2 Hydroxypropyl methylcellulose

29

Department of Pharmaceutics, Pharmaceutics, Bharathi College of Pharmacy

CONTENTS

4

Materials and Methods

31

4.1 Materials

31

4.2 Methods

33

4.2.1 Preformulation studies

33

4.2.2 Preparation of Flurbiprofen microspheres

34

4.2.3 Evaluation of Flurbiprofen microspheres

36

4.2.4 Preparation of cross-linked gelatin capsules

37

4.2.5 Physical tests

38

4.2.6 Chemical tests

39

4.3 Formulation of pulsatile (modified pulsincap) drug delivery system

40

4.3.1 Coating of pulsincap

40

4.3.2 Evaluation of modified pulsincap

41

5

Results

43

6

Discussion

64

7

Conclusion

70

8

Summary

71

9

Bibliography

73

10

Annexure

80

Department of Pharmaceutics, Pharmaceutics, Bharathi College of Pharmacy

LIST OF TABLES

LIST OF TABLES

Table No. 1.1

Title Circadian rhythm and manifestation of clinical diseases

Page No. 3

1.2

Average pH in the GI tract

16

1.3

Average GI transit time

17

1.4

Summary of colon-specific drug delivery strategies

18

4.1

Materials / Chemicals used

31

4.2

Equipments used and source

32

Formulation design of Flurbiprofen Microspheres using 4.3

35 Eudragit L-100 and Eudragit S-100 Standard calibration data of Flurbiprofen 1.2, 6.8 and 7.4

5.1

43 buffer at 247 nm

5.2

Micromeritic properties of Flurbiprofen Microspheres

46

Percentage yield and Drug content of Flurbiprofen 5.3

47 microspheres In-vitro release profile of Flurbiprofen microspheres for

5.4

48 F1 In-vitro release profile of Flurbiprofen microspheres for

5.5

49 F2 In-vitro release profile of Flurbiprofen microspheres for

5.6

50 F3 In-vitro release profile of Flurbiprofen microspheres for

5.7

51 F4

Department of Pharmaceutics, Bharathi College of of Pharmacy

LIST OF TABLES

Kinetic values obtained from in-vitro release profile for 5.8

52 microspheres Composition for modified pulsatile device on the basis of

5.9

56 design summary

5.10

Coating thickness

57

5.11

Weight variation

57

In-vitro release rate profile of F5 containing 20mg 5.12

58 HPMC In-vitro release rate profile of F6 containing 30mg

5.13

59 HPMC In-vitro release rate profile of F7 containing 40mg

5.14

60 HPMC Kinetic values obtained from in-vitro release profile for

5.15

61 microspheres

Department of Pharmaceutics, Bharathi College of of Pharmacy

LIST OF FIGURES

LIST OF FIGURES

Fig. No.

Title

Page No.

A 24-hours clock diagram of the peak time of selected 1.1

human circadian rhythms with reference to the day-night

3

cycle. 1.2

Drug release profile of pulsatile drug delivery systems

12

1.3

Different stages in drug release from pulsincap

14

1.4

Structure of colon

16

4.1

Overview of designed pulsatile device

41

5.1

Standard calibration curve of Flurbiprofen in pH 1.2

43

buffer 5.2

Standard calibration curve of Flurbiprofen in pH 6.8

44

buffer 5.3

Standard calibration curve of Flurbiprofen in pH 7.4

44

buffer 5.4

5.5

I.R. Spectrum of Flurbiprofen (pure drug) I.R. Spectrum of physical mixture of Flurbiprofen and

45

45

polymers Images of Flurbiprofen microspheres for F1, F2, F3 and 5.6

46 F4

Department of Pharmaceutics, Bharathi College of Pharmacy

LIST OF FIGURES

5.7 5.8

Scanning electron microphotographs of F3 formulation Cumulative % release of Flurbiprofen microspheres

47 52

5.9

Zero order plots of Flurbiprofen microspheres

53

5.10

First order plots of Flurbiprofen microspheres

53

5.11

Higuchi diffusion plots of Flurbiprofen microspheres

54

5.12

Peppas exponentional plots of Flurbiprofen microspheres

54

I.R. Spectrum of physical mixture of Flurbiprofen and 5.13

56 HPMC Cumulative % release of Flurbiprofen microspheres

5.14

containing HPMC as hydrogel plug

61

Zero order plots of formulation containing HPMC as 5.15

62 hydrogel plug First order plots of formulation containing HPMC as

5.16

62 hydrogel plug Higuchi diffusion plots of formulation containing HPMC

5.17

63 as hydrogel plug Peppas exponentional plots of formulation containing

5.18

63 HPMC as hydrogel plug

Department of Pharmaceutics, Bharathi College of Pharmacy

CHAPTER 1

INTRODUCTION

1. INTRODUCTION

Controlled drug delivery systems have acquired a centre stage in the area of pharmaceutical R &D sector. Such systems offer temporal and/or spatial control over the release of drug and grant a new lease of life to a drug molecule in terms of controlled drug delivery systems for obvious advantages of oral route of drug administration. These dosage forms offer many advantages, such as nearly constant drug level at the site of action, prevention of peak-valley fluctuation, reduction in dose of drug, reduced dosage frequency, avoidance of side effects and improved patient compliance. In such systems the drug release commences as soon as the dosage form is administered as in the case of conventional dosage forms. However, there are certain conditions, which demand release of drug after a lag time. Such a release pattern is known as “pulsatile release”.1 However, the major bottleneck in the development of drug delivery systems that match circadian rhythms (chronopharmaceutical drug delivery system: ChrDDS) may be the availability of appropriate technology. The diseases currently targeted for chronopharmaceutical formulations are those for which there are enough scientific backgrounds to justify ChrDDS compared to the conventional drug administration approach.

These include asthma,

arthritis,

duodenal

ulcer,

cancer,

diabetes,

cardiovascular diseases, hypercholesterolemia, ulcer and neurological diseases.2 ,3. Circadian variation in pain, stiffness and manual and manual deyterity in patients with osteo and rheumatoid arthritis have been studied and has implication for timing antirheumatoid drug treatment.4 Chronopharmacotherapy for rheumatoid arthritis has been recommended to ensure that the highest blood levels of the drug coincide with peak

Department of Pharmaceutics, Bharathi College of Pharmacy.

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CHAPTER 1

INTRODUCTION

pain and stiffness.5 A pulsatile drug delivery system that can be administered at night (before sleep) but that release drug in early morning would be a promising chronopharmaceutic system.5,6 Drug targeting to colon would prove useful where intentional delayed drug absorption is desired from therapeutic point of view in the treatment of disease that have peak symptoms in the early morning such as nocturnal asthma, angina, arthritis.1,4,7,8,

1.1 CIRCADIAN RHYTHMS AND THEIR IMPLICATIONS Circadian rhythms are self-sustaining, endogenous oscillation, exhibiting periodicities of about one day or 24 hours. Normally, circadian rhythms are synchronized according to the body’s pacemaker clock, located in the suprachiasmic nucleus of the hypothalamus. The physiology and biochemistry of human being is not constant during the 24 hours, but variable in a predictable manner as defined by the timing of the peak and through of each of the body’s circadian processes and functions. The peak in the rhythms of basal gastric and secretion, white blood cells (WBC), lymphocytes, prolactin, melatonin, eosinophils, adrenal corticotrophic hormone (ACTH), follicle stimulating hormone (FSH), and leuteinizing hormone (LH), is manifested at specific times during the nocturnal sleep span. The peak in serum cortisol, aldosterone, testosterone plus platelet adhesiveness and blood viscosity follows later during the initial hours of diurnal activity. Hematocrit is the greatest and airway caliber the best around the middle and afternoon hours, platelet numbers and uric acid peak later during the day and evening. Hence, several physiological processes in humans vary in a rhythmic manner, in synchrony with the internal biological clock as shown in Fig.1.14,9

Department of Pharmaceutics, Bharathi College of Pharmacy.

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CHAPTER 1

INTRODUCTION

Figure 1.1: A 24-hours clock diagram of the peak time of selected human circadian rhythms with reference to the day-night cycle.

Table 1.1: Circadian rhythm and manifestation of clinical diseases Disease or syndrome Allergic Rhinitis Asthma Rheumatoid Arthritis Osteoarthritis Myocardial Infraction Stroke Sudden cardiac death Peptic ulcer disease

Circadian rhythmicity Worse in the morning/upon rising Exacerbation more common during the sleep period Symptoms more common during the sleep period Symptoms worse in the middle/later portion of the day Incidence greatest in early morning Incidence higher in the morning Incidence higher in the morning after awakening Worse in late evening and early morning hours

Department of Pharmaceutics, Bharathi College of Pharmacy.

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CHAPTER 1

1.2

INTRODUCTION

CHRONOTHERAPEUTIC:

THERAPY

IN

SYNCHRONY

WITH

BIORHYTHMS Chronotherapy coordinates drug delivery with human biological rhythms and holds huge promise in areas of pain management and treatment of asthma, heart disease and cancer. The coordination of medical treatment and drug delivery with such biological clocks and rhythms is termed chronotherapy.10 The goal of chronotherapeutics is to synchronize the timing of treatment with the intrinsic timing of illness. The chronotherapy of a medication may be accomplished by the judicious timing of conventionally formulated tablets and capsules. In most cases, however, special drug delivery technology must be relied upon to synchronize drug concentrations to rhythms in disease activity.4 1.3 ARTHRITIS

11, 12, 13

The term arthritis is used to describe changes in the joints which may be either inflammatory or degenerative in character. If only one joint is affected the condition is referred to as monoarticular arthritis; if several joints are involved it is called polyarticular arthritis or polyarthritis (Greek: poly= many). Symptoms of arthritis: •

The joints ache and swell

•

Pain and muscle-spasm are common features; and in the late stages very severe pain and gross destruction and deformity of the joints may develop.

•

In children the condition tends to develop suddenly, many joints being affected from the beginning the small joint soft the hands and feet being as a rule affected first.

•

Severe muscle wasting might also take place

Department of Pharmaceutics, Bharathi College of Pharmacy.

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•

INTRODUCTION

Patients of arthritis can only walk a certain distance after which they tend to feel pain and stiffness in their joints.

•

Arthritis can also develop slowly starting as a slight restriction of movement in certain directions, with stiffness first thing in the morning and aches after exercises.

•

Arthritis can be both of the infective variety as well as the chronic.

•

In infective arthritis the patient feels ill and toxic with a swinging temperature and a furred tongue. Leucocytes are always evident, and a blood culture may confirm the presence of the septicaemia.

Some common forms of Arthritis: •

Rheumatic arthritis(fibromyalgia)

•

Rheumatoid arthritis(Still's Disease)

•

Degenerative, e.g. osteo-arthritis

•

Psoriatic arthritis

•

Ankylosing Spondylitis

Rheumatoid Arthritis: Rheumatoid arthritis is a form of chronic arthritis. This disease affects chiefly young adults, mainly women, and one or many joints may be involved; it also occurs in children (Still's Disease). It is generalized affection of joints, and their synovial membranes, cartilages, capsules and the muscles supplying them; but other connective tissues elsewhere in the body might also be affected. Rheumatoid arthritis is now a major cause of crippling in European countries, but it is not common in the tropics.

Department of Pharmaceutics, Bharathi College of Pharmacy.

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INTRODUCTION

Causes of Rheumatoid Arthritis: The causes of the conditions are not yet fully understood. While infection form the focus of the respiratory, alimentary, urinary or genital tracts is sometimes a factor, recent research has also demonstrated the importance of the endocrine glands as both as a cause and a therapy. Causes of osteoarthritis: •

This disease is caused due to a gradual destruction of cartilage. Its precise cause is unknown but it is no longer known as a simple wear and tear disease.

•

Hereditary seems to play a very important role in osteoarthritis.

•

How can an osteoarthritis patient be treated?

•

The treatment of osteoarthritis is simpler than that of the more severe forms of arthritis.

Fibromyalgia Fibromyalgia is a common condition. However it can get severe enough to start intruding into your day to day life. Fibromyalgia literally means, fibrous tissues (fibro-) and the muscles (-my-) being affected by pain (-algia). In this disease the whole body feels affected since the tendons and the ligaments both get affected. Fibromyalgia in fact affects the muscles and not the joints at all. Also, this form of arthritis never causes permanent damage to tissues though the symptoms may last for months or years. Causes fibromyalgia: •

Fibromyalgia is a functional disturbance which implies that its causes cannot purely be categorized as being physical or mental.

Both the person's mind as well as body is involved in this ailment.

Department of Pharmaceutics, Bharathi College of Pharmacy.

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•

INTRODUCTION

Sleep being vital to both the good health of the body as well as the mind, it comes as no surprise that a major cause of fibromyalgia is sleep disorders.

•

If a person has more light sleep than deep sleep then he is likely to be inflicted by Fibromyalgia.

Ankylosing Spondylitis This is a chronic inflammatory form of arthritis which affects the spinal joints. The main and the most important feature is that in this form of arthritis the joints between the spine and the pelvis get inflicted. This form of arthritis causes back ache and stiffness in the back as well as a hunched up body posture. In very severe cases there might be inflammations around the tendons and ligaments that connect and provide support to joints that lead to pain and tenderness in the shoulder blades and the spinal cord. Ankylosing Spondylitis can also impair mobility by creating inflammation of the vertebra. This ailment can have confusing symptoms since there can be varied kinds of manifestations. While some individuals suffer gouts of transient back ache only while others suffer chronic back aches that lead to differing degrees of back ache and stiffness. Colloquially, Ankylosing Spondylitis is referred to as poker back and rheumatoid Spondylitis. It is only about five decades back that this ailment got the name that is now prevalent. Since this ailment belongs to the family of diseases that attack the spine it is also referred to as, in medical jargon as spondylarthropathies. You must keep in mind that men are three times more at a risk of acquiring this disease than women. This ailment also attacks youngster’s more than older people, contrary to popular belief.

Department of Pharmaceutics, Bharathi College of Pharmacy.

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INTRODUCTION

Causes Ankylosing Spondylitis: •

Ankylosing spondylitis is believed to be hereditary since it depends on tissue type and we genetically inherit tissue types.

•

The exact cause of this ailment is however still not known.

•

Some researchers also believe that environmental interaction with certain tissue types might result in Ankylosing spondylitis.

Psoriatic arthritis Psoriatic arthritis is a less common form of arthritis which affects, men and women in an equal ratio, and usually strikes when they are between the ages of 20 to 50. It is marked by scaly growth of rough tissues around the joints. There are several types of psoriatic arthritis, with symptoms that range from mild to severe. In general, the disease isn't as crippling as other forms of arthritis, but if left untreated it can cause discomfort, disability and deformity. Although no cure exists for psoriatic arthritis, medication, physical therapy and lifestyle changes often can relieve pain and slow the progression of joint damage. Psoriatic arthritis causes swelling in the joints. It affects a number of joints including the fingers, wrists, toes, knees, ankles, elbows and shoulder joints, the spine and joints in the lower back (called sacroiliac joints). Psoriatic arthritis also affects tissues surrounding the joints including tendons and ligaments and causes inflammation and swelling and pain in and around the joints. This ailment usually affects the wrists, knees, ankles, fingers and toes. It also affects the back. One of these conditions is psoriatic arthritis, which may affect as many as 1 million of the approximately 6 million Americans who have psoriasis. In fact 30% of the people who have psoriasis later go onto have psoriatic arthritis.

Department of Pharmaceutics, Bharathi College of Pharmacy.

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INTRODUCTION

Causes of Psoriatic arthritis: •

The exact cause of psoriatic arthritis is unknown

•

As mentioned before psoriasis generally develops into psoriatic arthritis

•

It has been observed that people who have psoriatic arthritis patients in the house generally get inflicted by this ailment.

•

Exposure to infection, stress, alcohol, poor nutrition

•

Reaction to a medication or vaccine

•

Overexposure to the sun or prolonged exposure to irritating chemical such as disinfectants and pain thinners.

1.4 CHRONOPHARMACEUTICS2 Chronopharmaceutics is a branch of pharmaceutics devoted to design and evaluation of drug delivery system that release a bioactive agent at a rhythm that ideally matches

the

biological

requirement

of

a

given

disease

therapy.

Ideally

chronopharmaceutical drug delivery system (ChrDDS) should embody time-controlled and site specific drug delivery system. Evidence suggests that an ideal ChrDDS should: •

Be non-toxic within approved limits of use,

•

Have a real-time and specific triggering biomarker for a given disease state.

•

Have a feed-back control system (ex: self-regulated and adaptive capability to circadian rhythm and individual patient to differentiate between awake-sleep status),

•

Be biocompatible and biodegradable, especially for parentral administration,

•

Be easy to manufacture at economic cost and

•

Be easy to administer to patients and enhances compliance to dosage regimen.

Department of Pharmaceutics, Bharathi College of Pharmacy.

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INTRODUCTION

1.5 PULSATILE DRUG DELIVERY SYSTEMS Among modified-release oral dosage forms, increasing interest has currently turned to systems designed to achieve time specific (delayed, pulsatile) and site-specific delivery of drugs. In particular, systems for delayed release are meant to deliver the active principle after a programmed time period following administration. These systems constitute a relatively new class of device the importance of which is especially connected with the recent advances in chronopharmacology. It is by now well-known that the symptomatology of a large number of pathologies as well as the pharmacokinetics and pharmacodynamics of several drugs follow temporal rhythms, often resulting in circadian variations. Therefore, the possibility of exploiting delayed release to perform chronotherapy is quite appealing for those diseases, the symptoms of which recur mainly at night time or in the early morning, such as bronchial asthma, angina pectoris and rheumatoid arthritis. The delay in the onset of release has so far mainly been achieved through osmotic mechanisms, hydrophilic or hydrophobic layers, coating a drug-loaded core and swellable or erodible plugs sealing a drug containing insoluble capsule body.14 Delivery systems with a pulsatile release pattern are receiving increasing interest for the development of dosage forms, because conventional systems with a continuous release are not ideal. Most conventional oral controlled release drug delivery systems release the drug with constant or variable release rates. A pulsatile release profile is characterized by a time period of no release rates (lag time) followed by a rapid and complete release.

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These dosage forms offer many advantages such as •

Nearly constant drug levels at the site of action.

•

Avoidance of undesirable side effects.

•

Reduced dose andImproved patient compliance.

•

Used for drugs with chronopharmacological behaviour, a high first pass effect, the requirement of night-time dosing and site-specific absorption in GIT.

The conditions that demand pulsatile release include: •

Many body functions that follow circadian rhythm i.e. their waxes and wanes with time. Ex: hormonal secretions.

•

Diseases like bronchial asthma, myocardial infraction, angina pectoris, rheumatoid diseases, ulcer and hypertension display time dependence.

•

Drugs that produce biological tolerance demand for a system that will prevent continuous present at the biophase as this tend to reduce their therapeutic effect.

•

The lag time is essential for the drugs that undergo degradation in gastric acidic medium (ex: peptide drugs) irritate the gastric mucosa or induce nausea and vomiting.

•

Targeting to distal organs of GIT like the colon requires that the drug release is prevented in the upper two-third portion of the GIT. All of these conditions demand for a time-programmed therapeutic scheme

releasing the right amount of drug at the right time. This requirement is fulfilled by pulsatile drug delivery system, which is characterized by a lag time that is an interval of no drug release followed by rapid drug release.1 Pulsatile systems are basically time-controlled drug delivery systems in which the system controls the lag time independent of environmental factors like pH, enzymes,

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INTRODUCTION

gastrointestinal motility, etc. these time-controlled systems can be classified as single unit (tablet or capsule) or multiple unit (e.g., pellets) systems as shown in the Fig 1.2.1,15

Figure 1.2: Drug release profile of pulsatile drug delivery systems A: Ideal sigmoidal release, B, C: Delayed release after initial lag time 1) Single Unit Systems15,16,17,18 i) Drug delivery systems with eroding or soluble barrier coatings Most pulsatile delivery systems are reservoir devices coated with a barrier layer. The barrier dissolves or erodes after a specify lag period, after which the drug is released rapidly from the reservoir core. ii) Drug delivery systems with rupturable coatings In this the drug is released from a core (tablet or capsule) after rupturing the surrounding polymeric layer, caused by inbuilt pressure within the system. The pressure necessary to rupture the coating can be achieved with gas-producing effervescent excipients, osmotic pressure or swelling agents.

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INTRODUCTION

iii) Capsular shaped systems Several single unit pulsatile dosage forms with a capsular design have been developed. Most of them consist of an insoluble capsule body, containing the drug and a plug, which gets removed after a predetermined lag time because of swelling, erosion or dissolution. E.g., Pulsincap® system and Port® system. The Pulsincap® system consists of a water-insoluble capsule body (exposing the body to formaldehyde vapor which may be produced by the addition of trioxymethylene tablets or potassium permanganate to formalin or any other method), filled with the drug formulation and plugged with a swellable hydrogel at the open end. Upon contact with dissolution media or gastrointestinal fluid, the plug swells and comes out of the capsule after a lag time, followed by a rapid release of the contents. The lag time prior to the drug release can be controlled by the dimension and the position of the drug. In order to assure a rapid release of the drug content, effervescent agents or disintegrants were added to the drug formulation, especially with water-insoluble drug. Studies in animals and healthy volunteers proved the tolerability of the formulation (e.g., absence of gastrointestinal irritation). In order to overcome the potential problem of variable gastric residence time of a single unit dosage forms, the Pulsincap® system was coated with an enteric layer, which dissolved upon reaching the higher pH regions of the small intestine. Different stages in drug release from pulsincap was shown in Fig 1.3.

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INTRODUCTION

Figure 1.3 1.3: Different stages in drug release from pulsincap The plug consists of •

Swellable materials coated with insoluble, but permeable polymers (e.g., polymethacrylates)

•

Erodible compressed materials (e.g., HPMC, polyvinyl alcohol, polyethylene oxide)

•

Congealed melted polymers (e.g., saturated polyglycoated glycerides or glyceryl monooleate).

2) Multiparticulate Pulsatile Drug Delivery Systems: These have various advantages, when compared to single unit dosage forms, which include, a reproducible gastric residence time, no risk of dose dumping and the flexibility to blend with different compositions or release patterns e.g., pellets. However, drug loading in these systems is low because of higher need of excipients (e.g. sugar cores). Multiparticulate with pulsatile release profiles are usually reservoir-type type devices with a coating, which either ruptures or changes its permeability.

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INTRODUCTION

1.6 COLON SPECIFIC DRUG DELIVERY SYSTEMS (CSDDS) 16, 17 The colonic region of the gastrointestinal tract is one area that would benefit from the development and use of such modified release technologies. Although considered by many to be an innocuous organ that has simple functions in the form of water and electrolyte absorption and the formation, storage and expulsion of faecal material, the colon is vulnerable to a number of disorders including ulcerative colitis, crohn’s disease IBS and carcinomas. In addition, systemic absorption from the colon also be used as a means of achieving chronotherapy for diseases that are sensitive to circadian rhythms such as asthma, angina and arthritis. Structure and function of the Colon16 The colon forms the lower part of the gastrointestinal tract and extends from the ileocecal junction at the anus. The colon is upper five feet of the large intestine and the rectum is the lower six inches. While the colon is mainly situated in the abdomen, the rectum is primarily a pelvic organ. As shown in the Fig 1.4, the first portion of the colon is spherical and is called cecum. The appendix hangs off the cecum. The next portion of the colon, in the order in which contents flow, is the ascending (proximal) colon, just under the liver, the angle or bend is known as the hepatic flexure, located just beneath the rib cage. The colon then turns to a long horizontal segment, the transverse colon. Beneath the left rib cage, the colon turns downward at the haustra, to become the descending (distal) colon. In the left lower portion of the abdomen, the colon makes an S-shaped curve from the hip over the midline known as the sigmoid colon. The colon and rectum have an anatomic blood supply. Along these blood vessels are lymph nodes. Lymph

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INTRODUCTION

nodes are structures found in the circulating lymphatic system of the body that produce and store cells that fight infection, inflammation, foreign proteins and cancer.

Figure 1.4: Structure of colon pH in colon:7,16 Radiotelemetry shows the highest pH levels (7.5 (7.5±0.5) 0.5) in the terminal ileum. On entry into the colon, the pH drops to 6.4 6.4±0.6. 0.6. The pH in the mid colon is 6.6±0.8 6.6 and in the left colon 7.0±0.7. 0.7. There is a fall in pH on entry into the colon due to the presence of short chain fatty acids arising from bacterial fermentation polysaccharides. polysaccharide Table 1.2: Average pH in the GI tract Location

pH

Oral cavity

6.2-7.4

Oseophagus

5.0-6.0

Stomach

Fasted condition:1.5-2.0, Fed condition: 3.0-7.5 3.0

Small intestine

Jejunum:5.0-6.5, Ileum: 6.0-7.5

Large intestine

Right colon: 6.4, Mild colon and left colon:6.0-7.6 colon:6.0

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Gastrointestinal transit:7 Gastric emptying of dosage form is highly variable and depends primarily on whether the subject is fed or fasted and on the properties of the dosage forms such as size and density. The arrival of an oral dosage form at the colon is determined by the rate of gastric emptying and the small intestinal transit time. Although the surface area in the colon is low compared to the small intestine, this is compensated by the markedly slower rate of transit.

Table 1.3: Average GI transit time Oral

Transit time (hr)

Stomach

3(fed)

Small intestine

3-4

Large intestine

20-30

1.7 METHODS FOR TARGETING DRUG INTO THE COLON7,14,16,19,20 These applications are either drug specific (prodrug) or formulations specific (coated or matrix preparations). The most commonly used targeting mechanisms are: 1

pH-dependent delivery

2

Time dependent delivery

3

Pressure dependent delivery

4

Bacteria- dependent delivery

The possibility of exploiting delayed release to perform chronotherapy, is quite appealing for those diseases, the symptoms of which recur mainly at night time or in the early morning, such as bronchial asthma, angina pectoris and rheumatoid arthritis.21,22,23,24.

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Table 1.4: Summary of colon-specific drug delivery strategies16,19,20 Design strategy

Prodrugs

pHdepedent systems

Timedependent system

Microfloro activated system

Drug release triggering mechanisms Cleavage of the linkage bond between drug and carrier via reduction and hydrolysis by enzyme from colon bacteria. Typical enzymes include azoreductase, glycosidase, and glucuronidase. Combination of polymers with pH-dependent solubility to take advantage of the pH changes along the GI tract. The onset of drug release is aligned with positioning the delivery system in the colon by incorporating a time factor simulating the system transit in upper GIT.

Advantages

Able to achieve site specificity.

Formulation well protected in the stomach

Small intestine transit time fairly consistent.

Primarily fermentation of non-starch polysaccharides by colon anaerobic bacteria. Good site The polysaccharides are specificity with incorporated into the prodrugs and delivery system via film polysaccharides. coating and matrix formation.

Disadvantages It will be considered as a new chemical entity from regulatory prespective. So far this approch has been primarily constricted to achives releated to the treatment of IBD. Unpredictable sitespecificity of drug release because of inter/intra subject variation of pH between small intestine and the colon. Substantial variation in gastric retention times make it complicated in predicting the accurate location of drug release.

Diet and disease can affect colonic microflora; enzymatic degredation may be excessively slow.

In this work Flurbiprofen was selected for dosage development. Flurbiprofen [1,1’-biphenyl]-4-acetic acid, 2-fluoro-alpha-methyl-, is an important analgesic and non-steroidal anti-inflammatory drug (NSAID) also with anti-pyretic properties whose mechanism of action is the inhibition of prostaglandin synthesis. It is used in the therapy of rheumatoid disorders. The drug must be administered approximately 150200mg daily by oral in divided doses.25

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CHAPTER 2

AIMS AND OBJECTIVES OBJECTIVES

2. AIMS AND OBJECTIVES

To design and characterize an oral, drug delivery system of Flurbiprofen intended to approximate the chronobiology of arthrities, proposed for colonic targeting. It is a chronopharmaceutical approach for the better treatment of rheumatoid arthritis. Based on the concept that a formulation on leaving the stomach, arrives at the ileocaecal junction in about 6 hours after administration and difference in pH throughout GIT, a time and pH dependent pulsatile (or modified pulsincap), controlled drug delivery system was designed. This capsule consists of a non-disintegrating body and a soluble cap. The drug formulations is contained within the capsule body and separated from the water-soluble cap by a hydrogel polymer plug. The entire capsule is enteric coated to prevent variable gastric emptying. The enteric coating prevents disintegration of the soluble cap in the gastric fluid. On reaching the small intestine the capsule will lose its enteric coating and the polymer plug inside the capsule swells to create a lag phase that equals the small intestinal transit time. This plug ejects on swelling and releases the drug from the capsule in the colon. 2.1 PLAN OF RESEARCH WORK
Preformulation studies: •

Selection of polymer and its combinations suitable for the colonic drug delivery

•

Preparation of standard graph of Flurbiprofen using spectrometric methods.

•

Drug-polymer Interaction


Experimental designing for formulation and evaluation of Flurbiprofen microspheres: •

Preparation of Flurbiprofen microspheres by emulsification-solvent evaporation.

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AIMS AND OBJECTIVES OBJECTIVES


Evaluation of physicochemical parameters of Flurbiprofen microspheres. •

Particle size and flow property.

•

Percentage yield

•

Drug content uniformity

•

Surface topography by SEM

•

In vitro release studies

•

Release kinetics


Development and evaluation of modified pulsincap formulation: •

Formaldehyde treatment of capsule bodies.

•

Selection of swellable polymer for the hydrogel plug. The concentration and selection of hydrogel is such that it takes a particular time period (small intestinal time of 3-4 hrs) to be ejected out and release the drug in the colon.

•

Formulation of modified pulsincap.

•

Evaluation of the dosage forms for their physicochemical parameters, in vitro release rate and release kinetics.

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REVIEW OF LITERATURE

3. REVIEW OF LITERATURE

Listair CR et al.,

26

developed a chronopharmaceutical capsule drug delivery system

capable of releasing drug after predetermined time delays. The drug formulation is sealed inside the capsule body by an erodible table (ET). The release time is determined by an ET erosion rate and increases as the content of an insoluble excipient (dibasic calcium phosphate) and of gel forming excipient (HPMC) increases. Samantha MK et al.,

27

designed and evaluated Pulsincap drug delivery system of

Salbutamol sulphate for drug targeting to colon in disease condition like asthma. The invitro dissolution studies indicated that the onset of drug release was after 7 to 8 hrs of the experiment and revealed its better sustaining efficacy over a period of 24hrs. Young-II Jeong et al., 28 evaluated pressure-controlled colon delivery (PCDCS) capsules prepared by a dipping method. By consequently dipping in an ethanolic EC solution and alkalized enteric polymer solution, PCDCS were obtained after both the capsule body and cap were adjusted to the size of #2 capsules. Seshasayan A et al.,

29

studied release of Rifampicin from modified pulsincap

preparation, using different preparation of various hydrophilic polymer such as guar gum, cabapol-940, sodium alginate, hydroxypropyl methylcellulose, gum karaya and poly vinyl alcohol. Among all the polymers tested guar gum showed better sustaining capacity even at low concentration.

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Sangalli ME et al.,

REVIEW OF LITERATURE 30

performed in-vitro and in-vivo evaluation of an oral system

(ChronotropicTM) designed to achieve time & /or site specific release. Cores containing antipyrine as the model drug were prepared by tableting and both the retarding and enteric coatings were applied in fluid bed. Zahirul Khan MI et al., 31 formulated a pH-dependent colon targeted oral drug delivery system using methacrylic acid copolymers. Drug release was manipulated using Eudragit® 100-55 and Eudragit® S100 combinations. The coated tablets were tested invitro for their sutability for pH dependent colon targeted oral delivery. Howard Stevens NE et al.,

32

designed pulsincap® formulations to deliver a dose of

drug following 5 h delay and evaluated the capability of the formulation to deliver defetilide to the lower GIT. The combination of scintigraphic and pharmacokinetic analysis permits identification of the site of drug release from the dosage form and pharmacokinetic parameters to be studied in man in a noninvasive manner. Libo Yang et al., 33 reviewed the new approaches in-vitro and in-vivo evaluation of colon specific drug delivery systems. Ying-huan Li et al.,

34

developed a multifunctional and multiple unit system, which

contains versatile mini-tablets in a hard gelatin capsule, as Rapid release Mini-tablets (RMTs), Sustained-release Mini-Tablets (SMTs), Pulsatile Mini-Tablets (PMTs) and Delayed onset Sustained- release Mini tablets (DSMTs), each with various lag times of release. Tomohiro Takaya et al.,

35

studied the importance of dissolution process on systemic

availability of drugs delivered by colon delivery system. The relationship between inDepartment of Pharmaceutics, Bharathi College of Pharmacy

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REVIEW OF LITERATURE

vitro drug release characteristics from colon delivery systems and in-vivo drug absorption was investigated using three kinds of delayed-release systems. Pressure controlled colon delivery capsules for liquid preparations, time controlled colon delivery capsules for liquid and solid preparations and Eudragit S coated tablets for solid preparations were used in this study. Takashi Ishibashi et al.,

36

evaluated colonic absorbability of drugs dog using a novel

colon-targeted delivery capsule (CTDC). A series of dog studies were performed to examine the in- vitro/in-vivo relationship of drug release behaviour of the newly developed CTDC. Jonathan CDS et al.,

37

investigated the coating-dependent release mechanism of a

pulsatile capsule using Nuclear Resonance microscopy. Chrononopharmaceutical capsules, ethycellulose-coated to prevent water ingress, exhibited clearly different characteristic when coated by organic or aqueous processes. Mastiholimath et al.,

38

attempted was made to the small intestine (7.0–7.8). So, by

using the deliver theophylline into colon by taking the advantage of the fact that colon has a lower pH value (6.8) than mixture of the polymers, i.e. Eudragit L and Eudragit S in proper proportion, pH dependent release in the colon was obtained. Abraham S et al.,

39

reported modified pulsincap dosage form of metronidazle to target

drug release in colon by using extrusion-spheronization method. Srisagul Sungthongjeen S et al., 40 reported development of pulsatile release tablets with swelling and rupturable layers. Finally concluded that pulsatile release tablets with a

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REVIEW OF LITERATURE

swelling layer and rupturable ethyl cellulose coating were developed. The system released the drug rapidly after a certain lag time due to the rupture of ethyl cellulose film. 41

Krishnaiah YSR et al.,

developed colon targeted drug delivery systems for

mebendazole the tablets were evaluated for drug content uniformity, and were subjected to in vitro drug release studies. Differential scanning calorimetry (DSC). 42

Satyanarayana S et al.,

presented the delivery of drugs to the colon for local effects,

including drug candidates, methods used for studying colonic drug absorption and colonspecific drug delivery systems, role of absorption enhancers in colonic drug delivery, and the use of prodrugs, drugs coated with pH dependent or pH independent biodegradable polymers, or polysaccharide matrices Ram Prasad YV et al.,

43

assessed the utility of guar gum as a carrier for colon specific

drug delivery using indomethacin as model drug from an oral matrix tablet formulation containing 40 mg of drug and 340 mg of guar gum. Krishnaiah YSR et al.,

44

used guar gum as a carrier for colon specific and studied

influence of metronidazole and tinidazole on in-vitro release of albendazole from guar gum matrix tablet and it was found that the release of drug from guar gum formulations increased with a decrease in the dose of metronidazole / tinidazole. Leopold CS et al., 45 carried out in-vitro study for the assessment of poly (Laspartic acid) as a drug carrier for colon specific drug delivery, using dexamethasone as model drug. It was concluded that poly (L-aspartic acid) appears to be a suitable drug carrier for colon specific drug delivery.

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Rubinstein et al.,

REVIEW OF LITERATURE 46

showed that calcium pectinate-indomethacin tablets of both types,

i.e. compression coated and matrix tablets give no release of indomethacin at a pH-1.5 for 2 hrs.

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REVIEW OF LITERATURE

3.1 DRUG PROFILE25,48,49 3.1.1 FLURBIPROFEN Chemical Structure:

Molecular Formula:

C15H13FO

Average Molecular Weight:

244.2609

Drug Category: Analgesics, Anti-Inflammatory Agents, Non-Steroidal Antiinflammatory Agents, Carbonic Anhydrase Inhibitors, Cyclooxygenase Inhibitors Chemical Name: 2-(3-fluoro-4-phenylphenyl) propanoic acid Description: Solid. (Solid crystalline powder.) Odour: Practically odourless Taste: Not available Molecular Weight: 244.27 g/mole Color: White to yellowish. Melting Point: 110°C (230°F)

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REVIEW OF LITERATURE

Solubility: Partially soluble in methanol, Very slightly soluble in cold water. Insoluble in diethyl ether. Stability: The product is stable. Storage: Keep container tightly closed. Keep container in a cool, well-ventilated area. Pharmacokinetics: Flurbiprofen having a short half life (4 ± 1hours), pKa value 4.2 makes it an ideal candidate for the design of sustained release pulsatile drug delivery system. Flurbiprofen [1,1 – biphenyl] – 4-acetic acid, 2-fluro-alpha-methyl, is a important analgesic and non-steroidal anti-inflammatory drug (NSAID) also with anti-pyretic properties whose mechanism of action is the inhibition of prostaglandin synthesis. It is used in the therapy of rheumatoid disorders. Flurbiprofen is rapidly eliminated from the blood, its plasma elimination half-life is 3-6 hours and in order to maintain therapeutic plasma levels. The drug must be administered approximately 150-200mg daily by oral individual dosage. So with the proposed device a new lease of life to an existing drug molecule can be achieved. Chronotherapeutic drug delivery release profiles for Flurbiprofen was found to have generated pro-found interest for the treatment of several diseases including rheumatoid arthritis, hypertension, bronchial asthma, myocardial infarction, Angina pectoris, rheumatic disease and ulcer.

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REVIEW OF LITERATURE

3.2 POLYMER PROFILE 3.2.1 EUDRAGIT L 100 AND EUDRAGIT S10050 Chemical structure:

Synonyms : Methacrylic acid, Eudragit. Functional category : Film former, tablet binder. Chemical name: Copolymers synthesized from dimethylaminoethyl methacrylate and other neutral methacrylic esters. Eudrgit® L 100 and S 100 are anionic copolymers based on methacrylic acid and methyl methacrylate. The ratio of the free carboxyl groups to the ester groups is approx. 1:1 in eudragit® L 100 and approx. 1:2 in eudrgit® S 100.The average molecular weight is approx. 135,000. Description: White powders with a faint characteristic odour. Solubility: 1 g of eudragit® L 100 or eudragit® S 100 dissolves in 7 g methanol, ethanol, in aqueous isopropyl alcohol and acetone (containing approx. 3 % water), as well as in 1 N sodium hydroxide to give clear to slightly cloudy solutions. EUDRAGIT® L 100 and S 100 are practically insoluble in ethyl acetate, methylene chloride, petroleum ether and water.

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REVIEW OF LITERATURE

Stability and storage condition: Eudragit S 100 and L 100 polymers are stable at room temperature. Safety: Acute toxicity studies have been performed in rats, rabbits and dogs. No toxic effects were observed. Chronictoxicity studies were performed in rats over a period of 3 months. No significant changes were found in the animal organs. Applications in Pharmaceutical Formulation or Technology: Eudragit L 100 and S 100 are employed as film coating agents resistant to gastric fluid with solubility above pH 6.0 and 7.0 respectively, for enteric coating of formulations. 3.2.2 Hydroxypropyl methylcellulose 52,53 Chemical structure:

Non-proprietary names: Hypomellus, hydroxyl propyl methylcellulose 2208, 2906, 2910. Synonyms: Methyl hydroxypropylcellulose, Propylene glycol ether of methylcellulose, methylcellulose propylene glycol ether. Chemical Name & CAS Registry number: Cellulose, 2-hydroxypropylmethyl-ether Cellulose Hydroxypropylmethylether . Empirical formula: C8H15 – (C10H18O6) n – C8 H15 O5 Molecular weight: Approximately 86,000 Department of Pharmaceutics, Bharathi College of Pharmacy

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REVIEW OF LITERATURE

Description: An odourless, tasteless, whit or creamy coloured fibrous or granular powder. Functional category: Coating agent, film former, tablet binder, stabilizing agent, suspending agent, viscosity agent and emulsion stabilizer. Apparent Density: 0.25 – 0.75 g/cm3 Solubility: Soluble in cold water forming viscous colloidal solution, insoluble in chloroform, alcohol and ether, but soluble in mixture of methanol and methylene chloride. Viscosity: HPMC K4M: 4,000 cps Stability and Storage Condition: Very stable in dry conditions, Solutions are stable at pH 3.0 – 11.0. Store in a tight container, in a cool place. Incompatibility: Extreme pH conditions, oxidizing materials. Safety: Human and animal feeding studies have shown Hydroxypropyl methylcellulose to be safe.

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MATERIALS AND METHODS

4. MATERIALS AND METHODS

4.1 MATERIALS The following materials/chemicals were used in the works which are as follows:

Table 4.1: Materials / Chemicals used and source Sl. No.

Materials/ Chemicals

Name Of Supplier

1.

Flurbiprofen

Micro Lab. Bangalore

2.

Eudragit L-100

Micro Lab. Bangalore

3.

Eudragit S-100

Micro Lab. Bangalore

4.

HPMC (K4M

Micro Lab. Bangalore

5.

Span-80

Micro Lab. Bangalore

6.

Acetone

Merck Pvt. Ltd.

7.

Liquid paraffin(heavy)

Merck Pvt. Ltd.

8.

Petroleum ether 60-80 C

Merck Pvt. Ltd.

9.

Potassium di-hydrogen phosphate

Merck Pvt. Ltd.

10.

Sodium hydroxide

Merck Pvt. Ltd.

11.

Potassium Chloride

Merck Pvt. Ltd.

12.

Hydrochloric acid

Merck Pvt. Ltd.

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MATERIALS AND METHODS

EQUIPMENTS The equipments used in the present work are as follows: Table 4.2: Equipments used and source Sl. No.

Instruments

Source

1.

Electronic balance

Shimadzu Corporation- Japan

2.

UV/Visible spectrophotometer

Shimadzu 1700, Shimadzu Corporation. Japan

3.

Scanning electron microscopy

JEOL–6360A, Japan.

4.

FTIR spectrophotometer

Shimadzu, Shimadzu Corporation. Japan

5.

Magnetic stirrer

Remi Motor Equipments, Mumbai

6.

Electrolab dissolution apparatus

Electro lab.

(USPXXIII) 7.

Oven

Shital Scientific Industries, Mumbai

8.

pH meter

Elico II-122

9.

Distillation unit

Biotech India, Mumbai

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MATERIALS AND METHODS

4.2 METHODS 4.2.1 Preformulation studies •

Preparation of Calibration Curve in 1.2 pH buffer An accurately weighted amount of Flurbiprofen equivalent to 100 mg was dissolved

in small volume of ethanol, in 100 ml volumetric flask and the volume was adjusted to 100 ml with 1.2 pH buffer and further dilution were made with 1.2 pH buffer. A series of standard solution containing Beer’s Lambert’s range of concentration from 2 to 16 µg/ml of Flurbiprofen were prepared and absorbance was measured at 247 nm against reagent blank. All spectral absorbance measurement was on Shimadzu 1700 UV-visible spectrophotometer. •

Preparation of Calibration Curve in 6.8 pH phosphate buffer An accurately weighted amount of Flurbiprofen equivalent to 100 mg was dissolved

in small volume of ethanol, in 100 ml volumetric flask and the volume was adjusted to 100 ml with 6.8 pH phosphate buffer and further dilution were made with 6.8 pH phosphate buffer. A series of standard solution containing Beer’s Lambert’s range of concentration from 2 to 16 µg/ml of Flurbiprofen were prepared and absorbance was measured at 247 nm against reagent blank. All spectral absorbance measurement was on Shimadzu 1700 UV-visible spectrophotometer. •

Preparation of Calibration Curve in 7.4 pH phosphate buffer An accurately weighted amount of Flurbiprofen equivalent to 100 mg was dissolved

in small volume of ethanol, in 100 ml volumetric flask and the volume was adjusted to 100 ml with 7.4 pH phosphate buffer and further dilution were made with 7.4 pH phosphate buffer. A series of standard solution containing Beer’s Lambert’s range of concentration from 2 to 16 µg/ml of Flurbiprofen were prepared and absorbance was Department of Pharmaceutics, Bharathi College of Pharmacy

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MATERIALS AND METHODS

measured at 247 nm against reagent blank. All spectral absorbance measurement was on Shimadzu 1700 UV-visible spectrophotometer. •

Drug-polymer Interaction FT-IR spectra of the Flurbiprofen, FM3 formulation, Eudragit L-100, Eudragit S-100

were determined by using KBr pellet technique. Samples were scanned over the 5004000cm-1 Spectral region at a resolution of 4cm-1 . The ratio of the sample in KBr disc was 1% (shimadzu FT-IR spectrometer). To ensure no interaction has been occurred between the drug and polymers. 4.2.2 Preparation of Flurbiprofen microspheres •

Rationale for selection of ingredients and process: 39,40 From literature review, it was evident that the pH in the proximal colon ranges from

6.6 to 7.0. So the Eudragit L-100 and S-100 were combined in different ratios and solubility of these combinations was found that Eudragit L- 100 and S-100 in the ratio 1:2 was soluble in pH range of 6.6 to 7.0. Hence this combination was selected for preparation of microspheres. Pure acetone did not dissolve Eudragit; however acetone with 2% water fitted the criterion well. Liquid paraffin was used was used as the dispersion media or external phase. Petroleum ether was used to clean the microparticles since it removes liquid paraffin without the integrity of the microparticles. Solvent evaporation O/O (oil in oil) emulsification method was chosen since it yields more uniform particles.

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MATERIALS AND METHODS

Table 4.3: Formulation design of Flurbiprofen Microspheres using Eudragit L-100 and Eudragit S-100 Formulation Code

Sl.

•

No.

Ingredients

F1

F2

F3

F4

1.

Drug (mg)

1000

1000

1000

1000

2

Eudragit L-100 (mg)

166

333

500

666

3.

Eudragit S-100 (mg)

332

666

1000

1332

4.

Span-80 (ml)

0.5

0.5

0.5

0.5

5.

Acetone (ml)

50

50

50

50

Preparation of Flurbiprofen microsphere: Emulsification-solvent evaporation. 58, 59

Accurately weighted amount of Drug, Eudragit L-100 and S-100 as shown in Table-6 were dissolved in 50ml of acetone to form a homogenous polymers solution. Flurbiprofen was dispersed in it and mixed thoroughly. This organic phase was slowly poured at 150C into liquid paraffin (100 ml) containing 1% (w/w) of Span-80 with stirring at 1000 rpm to form a uniform emulsion. Thereafter, it was allowed to attain room temperature and stirring was continued until residual acetone evaporated and smooth-walled, rigid and discrete microspheres were formed. The microspheres were collected by decantation and the product was washed with petroleum ether (40–600C) and dried at room temperature for 3 hrs. The microspheres were then stored in a desiccators over fused calcium chloride.

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4.2.3 Evaluation of Flurbiprofen Microspheres Prepared microspheres of Flurbiprofen were evaluated for the following parameters: •

Particle size 60 Determination of average particle size of Flurbiprofen microspheres was carried out

by using optical microscopy. A minute quantity of microspheres was spread on a clean glass slide and average size of 600 microspheres was determined in each batch. •

Study of flow properties of microspheres61 Angle of repose (θ) of the microspheres, which measures the resistance to particle

flow, was determined by a fixed funnel method. The height of the funnel was adjusted in such a way that the tip of the funnel just touches the heap of the blends. Accurately weighed microspheres were allowed to pass through the funnel freely on to the surface. The height and diameter of the powder cone was measured and angle of repose was calculated using the following equation θ = tan-1 h/r Where h/r is the surface area of the free standing height of the microspheres heap that is formed on a graph paper after making the microspheres flow from the glass funnel. •

Percentage yield 62 The measured weight was divided by total amount of all non-volatile components

which were used for the preparation of microsphere. % yield = Total weight of excipient and drug / Actual weight of product x 100 •

Drug Content Uniformity 63 In 100ml volumetric flask 25mg of crushed microspheres were taken and dissolved

with small quantity of ethanol and the volume was made up to mark with pH 6.8 and

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MATERIALS AND METHODS

stirred for 12 hrs. After stirring the solution was filtered through whatman filter paper and from the filtrate appropriate dilutions were made and absorbance was measured at 247 nm by using UVspectrophotometer. •

Scanning Electron Microscopy 64 It has been used to determine particle size distribution, surface topography, texture

and examine the morphology of fractured or sectioned surface. The samples for SEM analysis were prepared by following method. Dry microspheres brass stub a coated with gold in an ion sputter. Then picture of microspheres were taken by random scanning of the stub. The SEM analysis or the microspheres was carried out by using JEOL–6360A analytical scanning electron microscope. The microspheres were viewed at an accelerating voltage of 20KV. •

In-vitro dissolution study 38,58 In vitro dissolution profile of each formulation was determined by employing USP

XXIII rotating basket method (900 ml of pH 6.8-phosphate buffer, 100 rpm and 37±0.50C). Microspheres equivalent to 150 mg of Flurbiprofen was loaded into the basket of the dissolution apparatus. Dissolution study carried out for 12 hrs. 5 ml of the sample was withdrawn from the dissolution media at suitable time intervals and the same amount was replaced with fresh buffer. The absorbance was measured at 247 nm by using Shimadzu 1700 UV spectrophotometer, against pH 6.8 as blank. 4.2.4 Preparation of Cross-Linked Gelatin Capsules 38, 39 •

Formaldehyde treatment Formalin treatment has been employed to modify the solubility of gelatin capsules.

Exposure to formalin vapours results in an unpredictable decreases in solubility of gelatin

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owing to the cross linkage of the amino group in the gelatin molecular chain aldehyde group of formaldehyde by Schiff’s base condensation. Procedure Hard gelatin capsule of size 00 and 000 in number taken. Their bodies were separated from the caps. 25 ml of 15% (v/v) formaldehyde was taken into desiccators and a pinch of potassium permanganate was added to it, to generate formalin vapours. The wire mesh containing the empty bodies of capsule was then exposed to formaldehyde vapours. The caps were not exposed leaving them water-soluble. The desiccators were tightly closed. The reaction was carried out for 12 h after which the bodies were removed and dried at 500C for 30 min to ensure completion of reaction between gelatin and formaldehyde vapours. The bodies were then dried at room temperature to facilitate removal of residual formaldehyde. These capsule bodies were capped with untreated caps and stored in a polythene bag. •

Tests for Formaldehyde Treated Empty Capsules Various physical and chemical test were carried out simultaneously for

formaldehyde treated and untreated capsules. 4.2.5 Physical tests •

Identification attributes The ‘00’ capsule were one with a red cap and red colored body. They were lockable

type, odorless, softy and sticky when treated with wet fingers. After formaldehyde treatment, there were no significant changes in the capsules. They were non-tacky when touched with wet fingers.

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MATERIALS AND METHODS

Visual defect In about 100 capsule bodies treated with formaldehyde, about ten were found to be

shrunk or distorted. •

Dimensions Variations in dimensions between formaldehyde, treated and untreated capsules were

studied. The length and diameter of the capsules were measured before and after formaldehyde treatment, using dial caliper. •

Solubility studies of treated capsules The solubility test was carried out for normal capsules and formaldehyde treated

capsules for 24 hrs. Ten capsules were randomly selected and then subjected to solubility studies at room temperatures in buffers of pH 1.2, 7.4 and 6.8. 100 ml solution and stirred for 24 hrs. The time at which the capsule dissolves or forms a soft fluffy mass was noted. 4.2.6 Chemical test •

Qualitative test for free formaldehyde51 Standard formaldehyde solution used is formaldehyde solution (0.002, w/v) and

sample solution is formaldehyde treated bodies (about 25 in number) were cut into small pieces and taken into a beaker containing distilled water. This was stirred for 1 hr with a magnetic stirrer, to solubilize the free formaldehyde. The solution was then filtered into a 50 ml volumetric flask, washed with distilled water and volume was made up to 50 ml with the washings. Procedure 1ml of sample solution, 9ml of water was added. One millilitre of resulting solution was taken into a test tube and mixed with 4ml of water and 5ml of acetone

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reagent. The test tube was warmed in a water bath at 400C and allowed to stand for 40 min. The solution was not more intensely colored than a reference solution prepared at the same time and in the same manner using 1ml of standard solution in place of the sample solution. The comparison should be made by examining tubes down their vertical axis. 4.3 FORMULATION OF PULSATILE (MODIFIED PULSINCAP) DRUG DELIVERY SYSTEM: 18,38,39,65 Microspheres equivalent to 150mg of Flurbiprofen were accurately weighed and filled into the previously formaldehyde treated bodies by hand filling. The bodies containing the microspheres were then plugged with different amounts of polymers hydroxylpropylmethylcellulose. Then join the capsule body and cap and sealed with a small amount of the 5% ethyl cellulose ethanolic solution. The sealed capsules were completely coated with 5% Cellulose Acetate Phthalate (CAP) to prevent variable gastric emptying. The whole system thus produced is modified pulsincap. Overview of designed pulsatile device was shown in Fig 4.1. 4.3.1 Coating of pulsincap 5 % w/w solution of CAP was prepared by using acetone: ethanol (8.2) as a solvent and dibutyl phthalate as plasticizer (0.75%) as a plasticizer. Dip coating method was followed to develop the pulsincap. The capsules were alternatively dipped in 5 % CAP solution and dried. Coating was repeated until an expected weight gain of.8-12% was obtained and the capsule resists disintegration in 0.1 N HCL for a minimum period of 2 hrs.

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Figure 4.1: Overview of designed pulsatile device 4.3.2 Evaluation of Modified Pulsincap 39,40 •

Drug Polymer Interaction FT-IR spectra of physical mixture of Flurbiprofen and HPMC were carried out by

using KBr pellet technique. Samples were scanned over the 500-4000cm-1 Spectral region at a resolution of 4cm-1. The ratio of the sample in KBr disc was 1% (shimadzu FTIR spectrometer). •

Thickness of cellulose acetate phthalate coating The thickness of cellulose acetate phthalate coating was measured using screw gauge

and expressed in mm. •

Weight variation 10 capsules were selected randomly from each batch and weight individually for

weight variation. •

In vitro release profile Dissolution studies were carried out by using USP XXIII dissolution test apparatus

(Basket) method. Capsules were placed in a basket so that the capsule should be immersed completely in dissolution media but not float. In order to simulate the pH Department of Pharmaceutics, Bharathi College of Pharmacy

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changes along the GI tract, three dissolution media with pH 1.2, 7.4 and 6.8 were sequentially used referred to as sequential pH change method. When performing experiments, the pH 1.2 medium was first used for 2 hrs (since the average gastric emptying time is 2 hrs) then removed and the fresh pH 7.4 phosphate buffer saline (PBS) was added. After 3 hrs (average small intestinal transit time is 3 hrs) the medium was removed and fresh pH 6.8 dissolution medium was added for subsequent hrs. 900ml of the dissolution medium was used at each time. Rotation speed was 100 rpm and temperature was maintained at 37±0.50C. 5ml of dissolution media was withdrawn at predetermined time intervals and fresh dissolution media was replaced. The withdrawn samples were analyzed at 247 nm, by UV absorption spectroscopy. •

Kinetics of drug release To examine the drug release kinetics and mechanism, the cumulative release data were

fitted to models representing zero order (Q v/s t), first order [Log(Q0-Q) v/s t], Higuchi’s square root of time (Q v/s t1/2 ) and Korsemeyer Peppas double log plot (log Q v/s log t) respectively, where Q is the cumulative percentage of drug released at time t and (Q0-Q) is the cumulative percentage of drug remaining after time t. In short, the results obtained from in vitro release studies were plotted in four kinetics models of data treatment as follows:
Cumulative percentage drug release Vs. Time (zero order rate kinetics)
Log cumulative percentage drug retained Vs. Time (first order rate kinetics)
Cumulative percentage drug release Vs. √T (Higuchi’s classical diffusion equation)
Log of cumulative percentage drug release Vs. log Time (Peppas exponential equation)

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5. RESULTS 5.1.1 Preformulation studies Table 5.1: Standard calibration data of Flurbiprofen in pH 1.2, 6.8 and 7.4 buffers at 247 nm SI.NO.

•

Concentration

Absorbance (247 nm)

(mcg/ml)

1.2

6.8

7.4

1

0.000

0.000

0.000

0.000

2

2.000

0.085

0.078

0.115

3

4.000

0.165

0.152

0.23

4

6.000

0.242

0.228

0.345

5

8.000

0.335

0.308

0.455

6

10.000

0.419

0.386

0.576

7

12.000

0.505

0.454

0.688

8

14.000

0.583

0.538

0.803

9

16.00

0.654

0.612

0.917

Standard calibration curve of Flurbiprofen in pH 1.2 buffer at 247 nm

Figure 5.1: Standard calibration curve of Flurbiprofen in pH 1.2 buffer at 247 nm Department of Pharmaceutics, Bharathi College of Pharmacy

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RESULTS RESULTS

Standard calibration curve of Flurbiprofen in pH 6.8 phosphate buffer at 247 nm

Figure 5.2: Standard calibration curve of Flurbiprofen in pH 6.8 buffer

•

Standard calibration curve of Flurbiprofen in pH 7.4 phosphate buffer at 247 nm

Figure 5.3: Standard calibration curve of Flurbiprofen in pH 7.4 buffer

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RESULTS RESULTS

Infrared spectroscopy The FT-IR spectra study showed no change in the finger print of pure drug spectra, thus confirming absence of drug and polymer interaction.

Figure 5.4: I.R. Spectrum of Flurbiprofen (pure drug)

Figure 5.5: I.R. Spectrum of physical mixture of drug and polymer combinations

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5.1.2 Preparation of Flurbiprofen microspheres

F1

F2

F3

F4

Figure 5.6: Image showing microspheres of Flurbiprofen formulations

5.1.3 Evaluation of Flurbiprofen microspheres •

Micromeritic properties Table 5.2: Micromeritic properties of Flurbiprofen Microspheres Formulation code

Mean particles size± ±S.D (µ µm)

Angle of repose± ±S.D

F1

164.62 ± 1.04

18° 75” ± 2.89

F2

168.12 ± 1.21

18° 62” ± 1.79

F3

195.99± 2.69

22° 09” ± 2.61

F4

249.92 ± 1.91

23° 36” ± 2.99

All values are represented as mean ± standard deviation (n=3)

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RESULTS RESULTS

Percentage yield and drug content Table 5.3: Percentage yield and Drug content of Flurbiprofen microspheres Formulation code

Percentage yield± ±S.D

Drug content uniformity± ±S.D

F1

89.61 ± 0.40

82.79% ± 0.68

F2

86.56 ± 0.27

88.23% ± 0.95

F3

91. 54 ± 0.18

96.19% ± 0.28

F4

88.85 ± 0.22

85.09% ± 0.16

All values are represented as mean ± standard deviation (n=3) •

Scanning Electron Microscopy (SEM)

Figure 5.7: Scanning electron microphotographs of F3 formulation.

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RESULTS RESULTS

Evaluation of In-vitro drug release of Flurbiprofen microspheres Table 5.4: In-vitro release data of Flurbiprofen microspheres (F1)

0.000

Cum.% Drug release ± SD 0.000

Cum.% Drug retained 0.000

0.70

-0.301

28.39 ± 1.06

71.61

1.453

1.854

1

1.00

0.000

34.06 ± 1.21

65.94

1.532

1.819

2

1.41

0.301

40.98 ± 1.30

59.02

1.612

1.770

3

1.73

0.477

47.66 ± 0.76

52.34

1.678

1.718

4

2.00

0.602

57.51 ± 1.10

42.49

1.759

1.628

5

2.23

0.698

61.02 ± 1.16

38.98

1.785

1.590

6

2.44

0.778

64.29 ± 1.04

35.71

1.808

1.552

7

2.64

0.845

68.72 ± 1.21

31.28

1.837

1.495

8

2.82

0.903

75.73 ± 0.92

24.27

1.879

1.385

9

3.00

0.954

79.8 ± 1.13

20.2

1.902

1.305

10

3.16

1.000

85.11 ± 0.98

14.89

1.929

1.172

11

3.31

1.041

91.01 ± 1.01

8.99

1.959

0.953

12

3.46

1.079

95.91 ± 0.94

4.09

1.981

0.611

Time (T) Hrs 0

Square root of Time 0.00

0.5

Log Time

Log Cum. Log Cum. % drug % Drug released retained 0.000 0.000

All values are represented as mean ± standard deviation (n=3)

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Table 5.5: In-vitro release data of Flurbiprofen microspheres (F2) Time (T) Hrs 0

Square root of Time 0.00

Log Time

Cum.% Drug release ± SD

0.000

0.000

Cum.% Drug retained 0.000

Log Cum. Log Cum. % drug % Drug released retained 0.000 0.000

0.5

0.70

-0.301

26.23 ± 1.08

73.77

1.418

1.867

1

1.00

0.000

36.08 ± 1.25

63.92

1.557

1.805

2

1.41

0.301

41.28 ± 1.10

58.72

1.615

1.768

3

1.73

0.477

45.03 ± 1.26

54.97

1.653

1.740

4

2.00

0.602

47.92 ± 1.08

52.08

1.680

1.716

5

2.23

0.698

55.11 ± 0.91

44.89

1.741

1.652

6

2.44

0.778

62.99 ± 1.95

37.01

1.799

1.568

7

2.64

0.845

68.09 ± 2.06

31.91

1.833

1.503

8

2.82

0.903

75.15 ± 1.84

24.85

1.875

1.395

9

3.00

0.954

84.79 ± 0.96

15.21

1.928

1.182

10

3.16

1.000

88.95 ± 1.27

11.05

1.949

1.043

11

3.31

1.041

90.76 ± 1.65

9.24

1.957

0.965

12

3.46

1.079

92.06 ±1.61

7.94

1.964

0.899

All values are represented as mean ± standard deviation (n=3)

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Table 5.6: In-vitro release data of Flurbiprofen microspheres (F3) Time (T) Hrs 0

Square root of Time 0.00

0.000

Cum.% Drug release ± SD 0.000

Cum.% Drug retained 0.000

0.5

0.70

-0.301

26.36 ± 0.25

73.64

1.420

1.867

1

1.00

0.000

31.17 ± 1.06

68.83

1.493

1.837

2

1.41

0.301

34.77 ± 1.11

65.23

1.541

1.814

3

1.73

0.477

41.21 ± 0.83

58.79

1.615

1.769

4

2.00

0.602

46.78 ± 0.91

53.22

1.670

1.726

5

2.23

0.698

54.06 ± 0.67

45.94

1.732

1.662

6

2.44

0.778

59.90 ± 0.85

40.1

1.777

1.603

7

2.64

0.845

62.92 ± 0.46

37.08

1.798

1.569

8

2.82

0.903

65.97 ± 0.76

34.03

1.819

1.531

9

3.00

0.954

72.09 ± 1.26

27.92

1.857

1.445

10

3.16

1.000

79.90 ± 1.42

20.1

1.902

1.303

11

3.31

1.041

82.96 ± 0.59

17.04

1.918

1.231

12

3.46

1.079

89.17 ± 1.28

10.83

1.950

1.034

Log Time

Log Cum. Log Cum. % drug % Drug released retained 0.000 0.000

All values are represented as mean ± standard deviation (n=3)

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Table 5.7: In-vitro release data of Flurbiprofen microspheres (F4) Time (T) Hrs 0

Square root of Time 0.00

0.000

Cum.% Drug release ± SD 0.000

Cum.% Drug retained 0.000

0.5

0.70

-0.301

24.10 ± 0.46

75.9

1.382

1.880

1

1.00

0.000

31.27 ± 0.39

68.73

1.495

1.837

2

1.41

0.301

37.06 ± 0.39

62.94

1.568

1.798

3

1.73

0.477

41.55 ± 0.19

58.45

1.618

1.766

4

2.00

0.602

47.39 ± 0.84

52.61

1.675

1.721

5

2.23

0.698

52.21 ± 0.47

47.79

1.717

1.679

6

2.44

0.778

59.44 ± 0.47

40.56

1.774

1.608

7

2.64

0.845

66.04 ± 0.24

33.96

1.819

1.530

8

2.82

0.903

71.92 ± 0.35

28.08

1.856

1.448

9

3.00

0.954

78.05 ± 0.37

21.95

1.892

1.341

10

3.16

1.000

80.78 ± 0.49

19.22

1.907

1.283

11

3.31

1.041

83.99 ± 0.01

16.01

1.924

1.204

12

3.46

1.079

87.81 ± 1.53

12.19

1.943

1.086

Log Time

Log Cum. Log Cum. % drug % Drug released retained 0.000 0.000

All values are represented as mean ± standard deviation (n=3)

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Figure 5.8: Cumulative % release of Flurbiprofen microspheres

Table 5.8: Kinetic values obtained from in-vitro release profile for Flurbiprofen microspheres

Formu lation Code

Zero order kinetic data(r2)

First order kinetic data(r2)

Higuchi Matrix kinetic data(r2)

F1

0.9190

0.07896

0.9884

0.973

0.2115

F2

0.9290

0.06747

0.9758

0.943

0.2236

F3

0.9359

0.01035

0.9814

0.959

0.2212

F4

0.9366

0.01492

0.9874

0.962

0.2457

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Peppas kinetic data ( r2 and n value)

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120

cum % drug release

100

80

F1 F2 F3 F4

60

40

20

0 0

5

10

15

20

25

30

Time(hrs)

Figure 5.9: Zero order plots of Flurbiprofen microspheres

Log % cum drug retained

2.0

1.5

F1 F2 F3 F4

1.0

0.5

0.0 0

5

10

15

20

25

30

Time(hrs)

Figure 5.10: First order plots of Flurbiprofen microspheres

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120 100

cum % drug release

80

F1 F2 F3 F4

60 40 20 0 1

2

3

4

5

6

Square root of time

-20 -40

Figure 5.11: Higuchi diffusion plots of Flurbiprofen microspheres

Log % cum drug release

2.5

-0.5

2.0

1.5

F1 F2 F3 F4

1.0

0.5

0.0

0.5

1.0

1.5

Log T

Figure 5.12: Peppas exponentional plots of Flurbiprofen microspheres

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5.1.4 Preparation of Cross-Linked Gelatin Capsules These capsule bodies were capped with untreated caps and stored in a polythene bag 5.1.5 Physical test •

Dimension

Average capsule length
Before formaldehyde treatment (untreated cap and body)

: 23.5 mm


After formaldehyde treatment (treated body and untreated cap) : 22.6 mm Average diameter of capsule body
Before formaldehyde treatment
After formaldehyde treatment

:

7.9 mm :

7.5 mm

:

20.6 mm

Average length of capsule body
Before formaldehyde treatment
After formaldehyde treatment •

:

19.5 mm

Solubility studies for the treated capsules When the capsules were subjected to solubility studies in different buffers for 24 hrs, the following observation were made

a) In all the case of normal capsules, both cap and body dissolved within fifteen minutes. b) In the case of formaldehyde treated capsules, only the cap dissolved within 15minutes, while the capsule remained intact for about 24 hours. 5.1.6 Quantity test for free formaldehyde The formaldehyde capsules were tested for the presence of free formaldehyde. The sample solution was not more intensely colored than the standard solution inferring that less than 20µg free formaldehyde is present in 25 capsule Department of Pharmaceutics, Bharathi College of Pharmacy

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RESULTS RESULTS

FORMULATION OF PULSATILE (MODIFIED PULSINCAP) DRUG

DELIVERY SYSTEM 5.2.1 Coating of pulsincap Table 5.9: Composition for modified pulsatile device on the basis of design summary Formul. No.

Wt.of empty Body(mg)

Wt.of micro sphere(mg)

Wt.of polymer used(mg)

Total weight With cap (mg)

Wt. after CAP coating (mg)

F5

67.5

355

20

442.5

451.34

F6

67.4

355

30

452.4

460.08

F7

68.5

355

40

463.5

473.25

HPMC: Hydroxy Propyl Methylcellulose.

5.2.2 Evaluation of modified pulsincap •

IR- Study From the spectra of pure drug and the combination of drug with polymers, it

was observed that all the characteristics peaks of Flurbiprofen were present in the combination spectrum, thus indicating compatibility of the drug and polymer.

Figure 5.13: I.R. Spectrum of physical mixture of Flurbiprofen and HPMC

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Thickness of Cellulose Acetate Phthalate Table 5.10: Coating thickness Formulation

Thickness of Coating (mm*)

F5

0.065

F6

0.053

F7

0.060

*Average of triplicate sets

•

Weight variation The filled capsules pass the weight variation test as their weights are within the

specified limits. Table 5.11: Weight variation Formulation

Weight variation (mg*)

F5

447.97

F6

456.21

F7

477.27

*Average of triplicate sets

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In vitro release profile Table 5.12: In-vitro release data of F5 containing 20mg HPMC

0.000

Log Cum. % drug released 0.000

Log Cum. % Drug retained 0.000

0.000

100

0.000

2.000

0.301

0.000

100

0.000

2.000

1.73

0.477

0.000

100

0.000

2.000

4

2.00

0.602

2.39 ± 0.25

97.61

0.378

1.989

5

2.23

0.698

5.70 ± 0.09

94.3

0.755

1.974

6

2.44

0.778

27.54 ± 0.53

72.46

1.439

1.860

7

2.64

0.845

32.51 ± 0.32

67.49

1.512

1.829

8

2.82

0.903

39.02 ± 0.78

60.98

1.591

1.785

9

3.00

0.954

43.09 ± 046

56.91

1.634

1.634

10

3.16

1.000

47.11 ± 0.16

52.89

1.673

1.723

11

3.31

1.041

55.17 ± 0.29

44.83

1.741

1.651

12

3.46

1.079

64.30 ± 0.30

35.7

1.808

1.552

13

3.60

1.113

66.50 ± 0.51

33.5

1.822

1.525

14

3.74

1.146

73.04 ± 0.80

26.96

1.863

1.430

15

3.87

1.176

75.96 ± 0.27

24.04

1.880

1.380

Time (T) Hrs

Square root of Time

Log Time

Cum.% Drug release ± SD

Cum.% Drug retained

0

0.00

0.000

0.000

1

1.00

0.000

2

1.41

3

All values are represented as mean ± standard deviation (n=3)

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Table 5.13: In-vitro release data of F6 containing 30mg HPMC

0.000

Log Cum. % drug released 0.000

Log Cum. % Drug retained 0.000

0.000

100

0.000

2.000

0.301

0.000

100

0.000

2.000

1.73

0.477

0.000

100

0.000

2.000

4

2.00

0.602

0.000

100

0.000

2.000

5

2.23

0.698

4.52 ± 0.12

95.48

0.655

1.979

6

2.44

0.778

26.98 ± 0.21

73.02

1.431

1.863

7

2.64

0.845

31.11 ± 0.12

68.89

1.492

1.838

8

2.82

0.903

34.96 ± 0.56

65.04

1.543

1.813

9

3.00

0.954

44.02 ± 0.22

55.98

1.643

1.748

10

3.16

1.000

49.14 ± 0.51

50.86

1.691

1.706

11

3.31

1.041

55.9 ± 0.22

44.1

1.747

1.644

12

3.46

1.079

63.12 ± 0.89

36.88

1.800

1.566

13

3.60

1.113

65.06 ± 0.17

34.94

1.813

1.543

14

3.74

1.146

68.58 ± 0.05

31.42

1.836

1.497

15

3.87

1.176

72.01 ± 0.25

27.99

1.857

1.447

Time (T) Hrs

Square root of Time

Log Time

Cum.% Drug release ± SD

Cum.% Drug retained

0

0.00

0.000

0.000

1

1.00

0.000

2

1.41

3

All values are represented as mean ± standard deviation (n=3)

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Table 5.14: In-vitro release data of F7 containing 40mg HPMC Log Log Cum.% Cum. Cum. Drug % drug % Drug retained released retained 0.000 0.000 2.000

Time (T) Hrs

Square root of Time

Log Time

Cum.% Drug release ± SD

0

0.00

0.000

0.000

1

1.00

0.000

0.000

100

0.000

2.000

2

1.41

0.301

0.000

100

0.000

2.000

3

1.73

0.477

0.000

100

0.000

2.000

4

2.00

0.602

0.000

100

0.000

2.000

5

2.23

0.698

0.42 ± 0.05

95.48

-0.376

1.979

6

2.44

0.778

5.72± 0.23

94.28

0.757

1.974

7

2.64

0.845

19.02 ± 0.34

80.98

1.279

1.908

8

2.82

0.903

28.98 ± 0.22

71.02

1.462

1.851

9

3.00

0.954

32.99 ± 0.56

67.01

1.518

1.826

10

3.16

1.000

38.07 ± 0.90

61.93

1.580

1.791

11

3.31

1.041

43.55 ± 0.27

56.45

1.638

1.638

12

3.46

1.079

51.25 ± 0.33

48.75

1.709

1.687

13

3.60

1.113

54.03 ± 0.39

45.97

1.732

1.662

14

3.74

1.146

56.87 ± 0.36

43.13

1.754

1.634

15

3.87

1.176

59.92 ± 0.51

40.08

1.777

1.602

All values are represented as mean ± standard deviation (n=3)

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Figure 5.14: Cumulative % release of Flurbiprofen microspheres containing HPMC as hydrogel plug

Table 5.15: Kinetic values obtained from in-vitro release data for Flurbiprofen microspheres

F5

0.9589

0.945

Higuchi Matrix kinetic data(r2) 0.923

F6

0.9503

0.943

F7

0.9306

0.942

Zero order First order Formulation kinetic kinetic Code 2 data(r ) data(r2)

Peppas kinetic data (r2 and n value) 0.880

2.622

0.930

0.821

2.724

0.937

0.926

2.459

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120

cum % drug release

100

80

F5 F6 F7

60

40

20

0 0

5

10

15

20

25

30

Time(hrs)

Figure 5.15: Zero order plots of formulation containing HPMC as hydrogel plug

Log % cum drug retained

2.5

2.0

F5 F6 F7

1.5

1.0

0.5

0.0 0

5

10

15

20

25

30

Time(hrs)

Figure 5.16: First order plots of formulation containing HPMC as hydrogel plug

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RESULTS RESULTS

120 100

cum % drug release

80

F5 F6 F7

60 40 20 0 1

2

3

4

5

6

Square root of ti me

-20 -40

Figure 5.17: Higuchi diffusion plots of formulation containing HPMC as hydrogel plug

Log % cum drug release

3

2

1

F5 F6 F7

0 0.5

1.0

1.5

Log T -1

Figure 5.18: Peppas exponentional plots of formulation containing HPMC as hydrogel plug

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CHAPTER 6

DISCUSSION

6. DISCUSSION In the current research, pulsatile drug delivery system containing eudragit microspheres with subsequently lower dose of Flurbiprofen for colon specific delivery was developed and evaluated. 6.1.1 Preformulation studies •

Standard calibration curve of Flurbiprofen Standard calibration curve of Flurbiprofen was carried out in 1.2 pH, 6.8 pH and

7.4 pH buffer at 247 nm. The r2 value in the entire medium shows nearly 1, which signifies linearity. (Fig 5.1 to 5.3 and Table 5.1) •

IR Studies Drug-polymer interaction study was carried out for pure drug and physical

mixtures of drug and polymers. Flurbiprofen was used in this study which contains carboxylic acid function responsible for a broad hump 3200 cm-1 .The aromatic C-H peaks was observed at 3076, 3063, 3032 cm-1. The broad carboxylic acid absorption is noticed at 1701 cm-1.

These data are in concurrent with the structure of the drug

molecular. (Fig 5.4). The physical mixture showed identical spectrum with respect to the spectrum of the pure drug, indicating there is no chemical interaction between the drug molecule and polymers. (Fig 5.5)

6.1.2 Preparation of Flurbiprofen microspheres Microspheres of Flurbiprofen were prepared using Eudragit L-100/S-100 by emulsion solvent evaporation method as shown in Table 4.3. In this method, the organic phase was slowly poured in liquid paraffin and the emulsion was stabilized by Span- 80. Department of Pharmaceutics, Pharmaceutics, Bharathi College of Pharmacy Pharmacy

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DISCUSSION

The organic phase evaporated and finally spherical, smooth–walled, rigid and discrete microspheres were formed. (Fig 5.6) 6.1.3 Evaluation of Flurbiprofen microspheres •

Particle size With increase in polymer concentration, the mean particle size of the

microspheres significantly increased and was range was between 164.62 to 249.92 µm. The reason for this is, as the polymer concentration increases, viscosity of medium increase and resulting in enhanced interfacial tension. Shearing efficiency is also diminished at higher viscosities. This may be resulting in the formation of large particles. (Table 5.2) •

Flow properties The value of θ for prepared microspheres was between 18° 75” - 23° 36” which

indicates reasonable flow and all the batches were found to fit with respect of flowability. (Table 5.2) •

Percentage yield Percentage yield of the formulation was carried out and was found to be within

the range between 86.56 to 91.54 %. (Table 5.3) •

Drug Content Drug content of the formulation was carried out and was found to be within the

range between 82.79 to 96.19%. (Table 5.3)

•

Scanning Electron Microscopy Scanning electron microscopy confirms the outer surface of F3 formulation was

smooth and dense, while the internal surface was porous. The shell of microspheres also Department of Pharmaceutics, Pharmaceutics, Bharathi College of Pharmacy Pharmacy

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DISCUSSION

showed some porous structure it may be caused by evaporation of solvent entrapped within the shell of microspheres after forming smooth and dense layer. (Fig 5.7) •

In-vitro release studies The In-vitro release studies of prepared Flurbiprofen microspheres were carried in

pH 6.8

buffer as a diffusion medium for a period of 12 hrs. As the amount of polymer

concentration increased, drug release from the formulations decreased. The release showed a biphasic release with an initial burst effect. At the end of first 30 min. drug release was 28.39%, 26.23%, 26.36% and 24.10% for F1 to F4 respectively.

The

mechanism for the burst release can be attributed to the drug loaded on the microcapsule or imperfect entrapment of drug.

The cumulative % release for F1, F2, F3 and F4 were found to be 95.91%, 92.06%, 89.17%, and 87.81% at the end of 12th hrs. (Tables 5.4 to 5.7 and Fig 5.8) The R2 values for zero order kinetics of F1, F2, F3 and F4 were 0.9190, 0.9290, 0.9359and 0.9366 respectively indicate the drug follows zero order release.(Table 5.8 an Fig 5.9) The R2 values for First order kinetics of F1, F2, F3 and F4 were 0.07896, 0.06747, 0.01035 and 0.01492respectively indicate the drug follows zero order release (Table 5.8 an Fig 5.10) To find out the drug release mechanism, the in-vitro data were subjected to Higuchi diffusion. The Higuchi diffusion plots of all the formulations were linear. Hence it confirms release follows Higuchi diffusion mechanism. (Table 5.8 and Fig 5.11)

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DISCUSSION

The formulations were subjected to peppas plots, results found fairly linear and slope value was calculated (n value) which was in ranges of 0.2115 to 0.2457 indicating the drug was released by Fickian diffusion mechanism. (Table 5.8 and Fig 5.12) 6.1.4 Preparation of Cross-Linked Gelatin Capsules Formaldehyde treatment of hard gelatin capsules The bodies of hard gelatine capsules were made insoluble by formaldehyde treatment.

This was done by exposing the bodies of the capsules to vapours of

formaldehyde; the caps were not exposed leaving them water-soluble. The capsules were tested for physical and chemical changes caused by exposure to vapours of formaldehyde. 6.1.5 Physical test •

Dimensions On formaldehyde treatment, the ‘00’ size capsule bodies showed a significant

decrease in length and diameter. •

Solubility studies When the capsules were subjected to studies in different buffers, the untreated

caps disintegrated within 10 mins in all the media whereas the treated bodies remained intact for about 24 hrs. •

Quantitative test for free formaldehyde The sample solution was less intensively coloured when compared with standard

inferring that less than 20 µg/ml of free formaldehyde is present in 25 capsules bodies (as per the I.P )

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6.2

DISCUSSION

FORMULATION OF PULSATILE (MODIFIED PULSINCAP) DRUG

DELIVERY SYSTEM

6.2.1 Coating of pulsincap Microspheres equivalent to 150 mg of Flurbiprofen were filled into the treated bodies and plugged with HPMC at different concentrations. The filled capsules were completely coated with 5% CAP solution. These pulsatile drug delivery systems were further evaluated. (Table 5.9) 6.2.2 Evaluation of modified pulsincap •

IR studies Drug-polymer interaction study was carried out for physical mixture of pure

drug(Flurbiprofen) and HPMC.The results rule out the incompatibility between drug and polymer ( Fig 5.13) •

Thickness The thickness of the CAP coating was measured by using screw gauge. The

values ranged from 0.053-0.065 mm. (Table 5.10) •

In-vitro release studies The dissolution studies, depicits the enteric coat of the cellulose acetate phthalate

was intact for nearly two hours in pH 1.2, but dissolved in intestinal pH, leaving the soluble cap of capsule, which also dissolved in pH 7.4 phosphate buffer. The exposed HPMC polymer plug which absorbed the surrounding fluid, star swelling and release the drug through the swollen matrix. After complete wetting of the plug, it formed a soft mass, which was then easily ejected out of the capsule body; releasing the eudragit microspheres into simulated colonic fluid (pH 6.8 phosphate buffer).

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DISCUSSION

In all the formulations, there was absolutely no drug release in pH 1.2, thus indicating the efficiency of 5% CAP for enteric coating. Very slight release was observed in pH 7.4 phosphate buffer. The F5, F6, F7 formulation at the end of 15th hrs shows the drug release of 75.96 %, 72.01 % and 59.92 % respectively. As the concentration of polymer increases the drug release decreases. (Tables 5.12 to 5.14 and Fig 5.14) The r2 value in higuchi plot confirms the drug release by Higuchi diffusion mechanism. The formulations were subjected to peppas plots by taking log cum % drug released versus log time. The plots are found fairly linear and the ‘r2’ values are near to 1 and also slope value was calculated (n value) which was in ranges of 2.459 to 2.724, indicating the drug was released by Super Case II transport diffusion mechanism. (Table 5.15 and Figs 5.15 to 5.18)

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CONCLUSION

7. CONCLUSION The results obtained from the study of “Design and evaluation of chronotherapeutic drug delivery system of flurbiprofen ” provide the following conclusion •

The particle size increased significantly as the amount of polymer increased.

•

The flow properties of all the prepared microspheres were good as indicated by low angle of repose (θ < 40º).The good flow properties suggested that the microspheres produced were non-aggregated.

•

As the entrapment efficiency was good in all the cases, suggest that optimized parameters were used in the method of preparations.

•

The In-vitro drug release of microspheres exhibits two type release pattern for all microspheres with initial burst release effect, which may be attributed to the drug loaded onto the surface of the particles.

•

On the basis of, particle size, drug content, Scanning Electron Microscopy, IRstudy, in-vitro release studies and its kinetic data, F3 was selected as an optimized formulation for designing pulsatile device.

•

The 1:2 ratio of Eudragit L-100 and S-100 are suitable for preparation of microspheres for colonic targeting.

•

The solubility studies of formaldehyde treated empty gelatine capsule bodies, signifies that they are intact for 24 hrs, and hence suitable for colon targeting.

•

Hence, finally it was concluded that the prepared pulsatile drug delivery system can be considered as one of the promising formulation technique for preparing colon specific drug delivery systems and hence in chronotherapeutic management of arthritis.

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SUMMARY

8. SUMMARY

Over the past two decades there has been a growing appreciation on the importance of circadian rhythms on GIT physiology and on disease states, together with the realization of the significance of time-of-day of the administration on resultant pharmacodynamics and pharmacokinetics parameters. The colon is a site where both local and systemic delivery of drug can take place. By targeting the drug to the colon the efficacy of the drug will be improved. In the present study, by keeping the objective of treating rheumatoid arthritis, an attempt was made to design and prepare chronotherapeutic, colon specific drug delivery system in order to target the drug to the colon. Flurbiprofen microspheres were prepared using Eudragit L/S 100 in ratio 1:2 by emulsion solvent evaporation method. Four formulations (F1 to F4) were prepared by varying the ratio of the drug and polymer. IR-study reveals there is not significant interaction between drug and polymers. The prepared formulations were subjected to various evaluation parameters like particle size, flow properties, percentage yield, drug content, scanning electron microscopy and in-vitro drug release studies. From the results, the formulation F3 emerges as the optimum formulation to design time and pH dependent, pulsatile drug delivery system. In the next step, the capsule bodies were made insoluble by formaldehyde treatment and these were subjected to various physical and chemical test such as dimension measurement, solubility studies and qualitative for free formaldehyde. Department of Pharmaceutics, Bharathi College of Pharmacy.

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SUMMARY

The microspheres equivalent to 150 mg of drug was filled in to the formaldehyde treated capsule bodies and plugged with HPMC at different concentration (20, 30 and 40 mg). The joint of the capsule body and cap was sealed with small amount of 5 % ethycellulose ethanolic solution. Then these filled capsules were completely coated with 5 % cellulose acetate phthalate solution. These pulsatile formulations were subjected to various tests such as thickness of CAP coating, weight variation and in vitro release studies. From the in vitro release studies of chrontherapeutic device, it was observed that with all the formulations, there was absolutely no drug release in simulated gastric fluid (acidic pH 1.2) for 2 hrs. Negligible amount of drug release was observed in simulated intestinal fluid (pH 7.4 phosphate buffer), where the dissolution were carried out for 3 hrs. At the end of 15 hrs the cumulative drug release for F5, F6 and F7 formulations was 75.96, 72.01 and 59.92 respectively. The result obtained promises the development of chronotherapeutic system for time and pH dependant drug release for the treatement of rheumatoid arthritis. Further work is to establish the therapeutic utility of this system by pharmacokinetics and pharmacodynamic studies on human beings.

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BIBLIOGRAPHY

9. BIBLIOGRAPHY

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BIBLIOGRAPHY

reduced burst effect and low ethycellulose content J Microencapsulation 2003;20 (3): 289-302. 64. Nizar Al-Zoubi, Alkhatib HS, Yasser Bustanji, Khaled Aiedeh, Starros Malamataris. Sustained-release of buspirone HCL by co spray-drying with aqueous polymeric dispersion. Eur J Pharma and Biopharm 2008;(69): 735-42. 65. Seshasayan A, Sreenivasa RB, Prasanna R., Ramana Murthy KV. Studies on Release of Rifampicin from modified pulsincap technique. Indian J Pharm Sci 2001:337–9.

Department of Pharmaceutics, Bharathi College of Pharmacy.

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CHAPTER 10

ANNEXURES

10. ANNEXURES

POSTER PRESENTATIONS 1. Vinay Kumar K V*, Dr. T. Sivakumar, Dr. Tamizh mani T. “Development of chrono pharmaceutical drug delivery system of flurbiprofen”. International Conference held on 20th & 21st August 2010 in PES College. MANUSCRIPT COMMUNICATION
Review article 1. Vinay Kumar K V*, T. Sivakumar, Tamizh mani T, Colon Targeting Drug Delivery System: A Review on Recent Approaches. International Journal of Current Pharmaceutical Research. (Communicated).
Research articles 1. Vinay Kumar K.V*, Sivakumar.T, Kavitha.K, Tamizmani.T Formulation and evaluation of flurbiprofen microspheres for colonic drug delivery system. International Journal of Current Research and Review. (Communicated). 2. Vinay Kumar K.V*, Sivakumar.T, Kavitha.K, Tamizmani.T. Formulation and evaluation of chronotherapeutic drug delivery system of flurbiprofen. Der Pharmacia Sinica. (Communicated).

Department of Pharmaceutics, Bharathi Bharathi College of Pharmacy

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