RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES
KARNATAKA, BANGALORE.
ANNEXURE II
PROFORMA FOR REGISTRATION OF SUBJECT FOR DISSERTATION
1 / Name of the candidate and address /Ms. VANAJAKSHI. m
D/o Smt. Seethamma Muniswamaiah, no;36‘Amruthavarshini’ , near Dasappa line building,
Chikkabidarakallu, Jindal nagar, Tumkur road,
Bangalore-560 073.
2 / Name of the Institution / Acharya & B. M. Reddy college of
pharmacy
Soladevanahalli, Chikkabanavara post, Hesaraghatta Main Road,
Bangalore-560 090.
3 / Course of the study and subject / M. Pharm.
( Pharmaceutics )
4 / Date of admission / June - 2008
5 / TITLE OF THE PROJECT:-
FORMULATION AND EVALUATION OF MICROSPHERES OF A HYPOLIPIDEMIC DRUG
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6.1 / BRIEF RESUME OF INTENDED WORK :-
Need for the study :-
The purpose of this research is to formulate and systematically evaluate in-vitro performance of microspheres of a hypolipidemic agent. Hyperlipidemia is the presence of raised or abnormal levels of lipids and / or lipoproteins in the blood. Lipid and lipoprotein abnormalities are extremely common in the general population, and are regarded as a highly modifiable risk factor for cardiovascular disease due to the influence of cholesterol, one of the most clinically relevant lipid substances, on atherosclerosis. In addition, some forms may predispose to acute pancreatitis. 1
Simvastatin is a hypolipidemic drug belonging to the class of "statins". It is used to control hypercholesterolemia (elevated cholesterol levels) and to prevent cardiovascular disease. From recent research it has become apparent that simvastatin inhibit the progression of atherosclerosis beyond their effects on Low density lipoprotein. Simvastatin acts by inhibiting HMG-CoA reductase, the rate-limiting enzyme of the mevalonate pathway, the metabolic pathway responsible for the endogenous production of cholesterol. The drug is in the form of an inactive lactone that is hydrolized after ingestion to produce the active agent. It has a very low bioavailability of 5% and a shorter half life of 3 – 4 hrs.2
Conventional oral dosage forms such as tablets, capsules provide specific drug concentration in systemic circulation without offering any control over drug delivery and also cause great fluctuations in plasma levels. For drugs with short half-lives and with a clear relationship between concentration and response, it will be necessary to dose at regular, frequent intervals in order to maintain the concentration within the therapeutic range. Higher doses at less frequent intervals will result in higher peak concentrations with the possibility of toxicity. To obtain maximum therapeutic efficacy, it becomes necessary to deliver the agent to the target tissue in the optimal amount for the right period of time thereby causing little toxicity and minimal side effects. A well designed controlled drug delivery system can overcome the problems of conventional therapy and enhance the therapeutic efficacy of a given drug. There are various approaches in delivering a therapeutic substance to the target site in a sustained or controlled release fashion. 3
One such approach is using polymeric microspheres as carriers for drugs. Microspheres are characteristically free flowing powders consisting of proteins or synthetic polymers which are biodegradable in nature and ideally having a particle size less than 200 micrometer. Microsphere based drug delivery systems have received considerable attention in recent years. The most important characteristic of microspheres is the microphase separation morphology which endows it with a controlled variability in degradation rate and also drug release.
Micro encapsulation for oral use has been employed to control the drug release, and to reduce or eliminate gastrointestinal tract irritation. In addition, multiparticulate delivery systems spread out more uniformly in the gastrointestinal tract. This results in more reproducible drug absorption and reduces local irritation when compared to single-unit dosage forms. 3
6.2 / REVIEW OF LITERATURE:-
Sustained release casein–chitosan microspheres containing diltiazem hydrochloride were prepared with colloidal co-acervation technique in a completely aqueous environment. Formaldehyde was used for the surface hardening of the droplets by cross-linking and thus fixing the shape and surface morphology of the formed microspheres. The dissolution profiles of diltiazem from casein–chitosan microspheres showed retarded release pattern of the drug into distilled water. The retarded release of diltiazem was increased by increasing casein concentration, and stirring time. On the other hand, increasing chitosan concentration and using high initial drug loading showed a fast drug release.5
Chitosan microspheres containing furosemide were prepared from a w/o emulsion system using liquid paraffin as the external phase and a solution of chitosan in acetic acid as the disperse phase. Discrete spherical furosemide microspheres having a 350–690 μm diameter range were produced. Microsphere properties were affected by the preparation variables such as the type and concentration of chitosan, drug concentration, cross-linking process, the viscosity of oil and stirring rate during the preparation. The results were examined kinetically. Dissolution data indicated that the release followed the Higuchi matrix model.6
Captopril microspheres were prepared by spherical crystallization technique using acrylic polymer (Eudragit RL 100, Eudragit RS 100) and Ethyl cellulose as matrix. The microspheres were spherical with diameter 150-300μm and incorporation efficiency of 40-65%. In vitro release was carried out in phosphate buffer of pH 7.4 using dissolution apparatus USP XIX (basket model) and analyzed spectrophotometrically at 207nm. Increase in concentration of polymer decrease drug release rate and increase in stirring rate increase drug release. The most retardant effect was obtained using Eudragit RS 100. Dissolution data indicated that drug release follow Baker-Lonsdale spherical matrix model kinetics.7
Erythropoietin (EPO, a protein easily denatured and antigenized by contact with water-organic solvent interfaces) was microencapsulated into poly(lactic-co-glycolic acid) (PLGA) microspheres with minimal aggregation. This formulation process involved an aqueous-aqueous emulsion formed at reduced temperature. Single injection of these EPO-loaded PLGA microspheres to mice resulted in a red blood cell elevation equivalent to twelve injections of the solution formulation. An ELISA assay suggested that the mice injected with the EPO-loaded PLGA microspheres did not develop anti-EPO IgG more than those given solution form erythropoietin.8
Carbohydrate polymeric blend microspheres, consisting of sodium alginate and methylcellulose were prepared by water-in-oil (W/O) emulsion method. These microspheres were cross-linked with glutaraldehyde and loaded with nifedipine. Scanning electron microscopy picture of the microspheres suggested the formation of spherical particles. Swelling experiments on the microspheres provided important information on drug diffusion properties. The controlled release characteristics of the matrices for nifedipine were investigated in pH 7.4 media. Particle size and size distribution of the microspheres was studied by laser light diffraction particle size analyzer. Drug was released in a controlled manner upto 12h.9
A set of novel porous polysucrose microspheres were prepared by the inverse suspension polymerization using soluble polysucrose, epichlorohydrin as cross linker and dimethyl ether of polyethylene glycol as porogen. The Fourier transform infrared spectrometer (FTIR), optical microscope, scanning electronic microscope and laser diffraction method were utilized to characterize the structure and morphology of the porous microspheres. The results indicated that these beads had spherical shape with the mean particle size of around 340 lm, narrow distribution, and porous structure. The equilibrium water contents of these porous microspheres ranged from 92.1% to 96.6% with the increasing contents of porogen. The porosities ranged from 82.3% to 90.3% with the increasing hydroxyl contents from 19.3 to 21.8 mmol/g, and bovine serum albumin (BSA) was used as adsorbate model to examine the adsorption behavior of the porous microspheres. The saturated adsorption capacities of these microspheres ranged from 42.6 to 98.5 mg/g.10
Polylactic acid (PLA) microspheres were prepared as a biodegradable polymeric carrier for nimesulide. The preparation of this system was performed by the emulsion solvent-evaporation method. Size analysis of the micro particulate system showed that unloaded and loaded nimesulide-PLA microspheres had average diameters of about 42.9 nm and 2.1_m, respectively. Scanning electron microscopy (SEM) of loaded and unloaded microsphere samples showed that the particles shape were perfectly spherical, the loading efficiency of nimesulide in PLA microspheres was 70%. Thus, the microparticle system evaluated in this work showed the potential to act as a sustained release system for nimesulide: in vitro dissolution profiles showed the polylactic acid micro particles were able to sustain the release of the drug for a considerable period of time (28.7% within 108 h).11
Ethyl cellulose blends were produced using different precipitation techniques and impregnated with naproxen. Solvent-evaporation technique was used not only for the preparation of ethyl cellulose microspheres but also to encapsulate naproxen. Supercritical fluid (SCF) impregnation was also performed to prepare naproxen loaded microspheres. The microspheres, impregnated by the SCF technique, were prepared both by solvent-evaporation and by a supercritical antisolvent (SAS) process. In vitro release profiles at pH 7.4 and 1.2, of naproxen-loaded microspheres were evaluated and the results were modelled Fick’s law of diffusion and power law. Microspheres prepared by supercritical antisolvent have a higher loading capacity and present a slower release profile. The systems studied presented a release mechanism controlled by drug diffusion which complied Fick’s law of diffusion.12
Microspheres of Eudragit L100 and S100 containing Insulin, protease inhibitor and bile salts were prepared by solvent diffusion technique. There was no interaction between drug, polymers and adjutants which was evaluated by FTIR. In vitro release studies were carried out using metabolic shaker. The In vivo hypoglycemic effect was determined in rats by measuring the blood glucose level using a glucometer. In vivo showed prolonged hypoglycemic effect for 3h when compared with intravenous injection of bovine insulin.13
Doxycycline-loaded chitosan microspheres were developed using a novel water-in-oil emulsion technique, along with an ionic co-acervation technique. Microspheres were prepared by using chitosan, soya oil–n-octanol oil mixture as continuous phase and span 80 as emulsifier. The drug-loaded spheres were spherical with smooth surface morphology. The MTT assay showed that doxycycline-loaded microspheres were able to improve the percentage cell viability in comparison to the pure drug. Assessment of antibacterial activity showed that doxycycline was able to exhibit a minimum microbicidal concentration of against Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa, respectively. This investigation provides scope for using doxycycline-loaded chitosan microspheres for healing infected wounds.14
Monodisperse poly(lactide-co-glycolide) (PLGA) microspheres containing rifampicin (RFP), as hydrophobic model drug were prepared by solvent evaporation method with a membrane emulsification technique using Shirasu Porous Glass (SPG) membranes. Five kinds of rifampicin-loaded PLGA (RFP/PLGA) microspheres with different sizes were prepared by changing pore size of the membranes. Effect of polyethylene glycol (PEG) added to polyvinyl alcohol (PVA) solution (continuous phase) upon the monodispersity of microspheres was studied. PEG was used as a stabilizer for microspheres dispersing in PVA solution. The most suitable molecular weight of PEG as a stabilizer was 20,000. RFP/PLGA microspheres prepared with PEG20000 were apparently more uniform than those prepared without PEG. The yield of RFP/PLGA microspheres was 100%. The initial burst observed in the release of RFP from RFP/PLGA microspheres was suppressed by the addition of PEG.15
6.3 / OBJECTIVE OF THE STUDY:-
Following are the objectives of the present study.
1. To carryout the preformulation studies of drug/polymer interaction by FTIR.
2. To develop and formulate microspheres for simvastatin.
3. To evaluate physical characters of the formulated microspheres like drug entrapment study, particle size, swelling index, flow properties of the microspheres.
4. To carryout In vitro release studies of the microspheres.
5. To carryout short term stability studies of the best formulation as per the ICH guidelines 30 ± 2º C (65 ± 5% RH) and 40 ± 2º C (75 ± 5% RH).
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7.1 / MATERIALS & METHODS:-
SOURCE OF DATA:-
1.Review of literature from Journals such as;
· Indian Journal of Pharmaceutical Sciences.
· Journal of Controlled Release.
· International Journal of Pharmaceutics.
· Carbohydrate polymers.
· Drug Delivery technology.
· Indian Drugs.
· European journal of Pharmaceutical sciences.
2. World wide web.
3.J-Gate@Helinet.
7.2 / METHOD OF COLLECTION OF DATA:-
1. To construct standard calibration curve of simvastatin.
2. To carry out preformulation studies like drug/ polymer interaction by FTIR
3. Formulation of microspheres.
4. In vitro evaluation of physico-chemical properties of microspheres like:
· Drug Entrapment Efficiency.
· Particle Size and Swelling Index of Microspheres.
· Percentage Yield.
· Flow properties.
5. In vitro drug release of the formulation.
6. To carry out short term stability studies of the best formulation as per ICH guidelines at 30 ± 2º C (65 ± 5% RH) and 40 ± 2º C (75 ± 5% RH).
7.3 / Does the study require any investigation or investigation to be conducted on patient or other humans or animals?
“NO”
7.4 / Has ethical clearance been obtained from your institution in case of 7.3?
“NOT APPLICABLE”
8. / list of references;
1. http://en.wikipedia.org/wiki/Hyperlipoproteinemia.
2. http://en.wikipedia.org/wiki/simvastatin.
3. Jain NK. Controlled and Novel drug delivery. 1st ed. CBS publishers and distributors, New Delhi, p. 237-251.
4. Mathew T. Sam, Devi S. Gayathri, Prashanth V.V, Vinod B. NSAIDs as Microspheres. The Int J Pharmacol. 2008;6(1)
5. Bayomi MA, Al-Suwayeh SA, El-Helw AM, Mesnad AF. Preparation of casein- chitosan microspheres containing diltiazem hydrochloride by an aqueous
Co-acervation technique. Int J Pharm. 1998;73(4):187-92.
6. Akbuja J, Durmaz G. Preparation and evaluation of cross linked microspheres containing furosemide. Int J Pharm. 1994;111(3):217-22.
7. Jayaswal SB, Reddy TSR, Vijay Kumar Gupta. Preparation and Evaluation of Captopril microspheres by spherical crystallization. Indian Drugs. 1995;32(9):454-57.
8. Geng Y, Yuan W, Fei W, Chen J, He M, Jin T. Formulating erythropoietin-loaded sustained release PLGA microspheres without protein aggregation. J.controlled release. 2008;130(3):259-65.
9. Ramesh BV, Sairam M, Hosamani KM, Aminabhavi TM. Preparations of sodium alginate methyl cellulose blend microspheres for controlled release of nifedipine. Carbohydrate polymers. 2007;69(2):241-50.
10. Hou X, Wang X, Gao B, Yang J. Preparation and characterization of porous polysucrose microspheres. Carbohydrate polymers. 2008;72(2):248-54.
11. Freitas MN, Marchetti JM. Nimesulide PLA microspheres as a potential sustained release system for the treatment of inflammatory diseases. Int J Pharm. 2005;295(1-2): 201-11.
12. Duarte ARC, Costa MS, Simplicio AL, Cardosa MM, Catarina MMD. Preparation of controlled release microspheres using supercritical fluid technology for delivery of anti-inflammatory drugs. Int J Pharm. 2006;308(1-2):168-74.
13. Gowthamarajan K, Girraj KT, Senthil RD, Suresh B. Microspheres as Oral Delivery System for Insulin. Ind J Pharm Sci. 2003; 65 (2):176-9.
14. Shanmuganathan S, Shanmugasundaram N, Adhirajan N, Lakshmi RTS, Babu M. Preparation and characterization of chitosan microspheres for doxycycline delivery. Carbohydrate polymers. 2008;73(2): 201-11.
15. Ito F, Fujimori H, Honnami H, Kawakami H, Kiyoshi K, Makino K. Effect of polyethylene glycol on preparation of rifampicin-loaded PLGA microspheres with membrane emulsification technique. Colloids and Surfaces B: Biointerfaces 2008; 66(1):65-70.
9 / Signature of the candidate:
10 / Remarks of the Guide:
11 / Name and Designation of:
11.1 / Institutional Guide: / Mr. SHIVANAND KALYANAPPA
Assistant Professor
11.2 / Signature:
11.3 / Head of the Department: / Dr. ROOPA KARKI
Professor & HOD
Department of Pharmaceutics
Acharya & B.M. Reddy college of Pharmacy, Chikkabanavara post,
Hesaragatta main road, Soladevanahalli,
Bangalore-560 090.
11.4 / Signature
12 / 12.1 / Remarks of the Principal
12.2 / Signature /
Dr. DIVAKAR GOLI. M.Pharm, Ph.D
Principal
Acharya & B.M. Reddy college of pharmacy, Chikkabanavara post, Hesarghatta main road, Soladevanahalli, Bangalore-560090.13