Formulation, characterization and in vitro evaluation of floating microspheres of famotidine as a gastro retentive dosage form

Abhishek Kumar Jain, C P Jain, Y S Tanwar, P S Naruka


different polymers, i.e. acrycoat S100 and cellulose acetate. The size or average diameter (davg) and surface morphology of the prepared microspheres were recognized and characterized by the optical and scanning electron microscopic methods, respectively. In vitro drug release studies were performed and the drug release kinetics were evaluated using the linear regression method. Effects of the stirring rate during preparation, polymer concentration on the size of the microspheres and drug release were also observed.The prepared microspheres exhibited prolonged drug release (18 h) and remained buoyant for more than
12 h. The mean particle size increased and the drug release rate decreased at a higher polymer concentration. No significant effect of the stirring rate during preparation on drug release was observed. In vitro studies demonstrated a diffusion-controlled drug release from the microspheres. The objective of the present study was to develop floating microspheres of FM in order to
achieve an extended retention in the upper gastrointestinal tract, which may result in enhanced absorption and thereby improved bioavailability. The prepared microspheres were evaluated for particle size, in vitro release and buoyancy and incorporation efficiency.The effect of various formulation variables on the size and drug release was investigated. In vitro drug release studies were performed and the drug release kinetics were evaluated using the linear regression method. FM was obtained as a gift sample from Intas Pharmaceuticals, Ahmedabad, India. Polyvinyl alcohol was obtained from S.D. Fine Chemicals Ltd., Mumbai,
India. Dichloromethane, acrycoat S100, cellulose acetate and Tween 80 were obtained from Central Drug House (P) Ltd., Delhi, India. All other chemicals/reagents used were of analytical grade. A UV/visible spectrophotometer was used for drug analysis. Experimental results were expressed as mean ± SD. Chi-square test and one-way analysis of variance (ANOVA) were applied to check significant differences in drug release from different formulations. Differences were considered to be statistically significant at P = 3.23, DF = 1, i.e. P < 0.05. The prepared floating microspheres exhibited prolonged drug
release, i.e. <18 h, and the floating time was <12 h in 0.1 N HCl.The mean particle size of the prepared floating microspheres increased but the drug release rate from the microspheric-coated layer decreased as the polymer concentration increased. No significant effect of the stirring rate during preparation on drug release was observed. In vitro data obtained for floating microspheres of FM showed excellent floatability, good buoyancy and prolonged drug release. Microspheres of different size and drug content could be obtained by varying the formulation variables. Diffusion was found to be the main release
mechanism.Thus, the prepared floating microspheres may prove to be potential candidates for multiple-unit delivery devices
adaptable to any intragastric condition.

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Seth PR, Tossounian J. The hydrodynamically balanced system HBSTM:

A novel drug delivery system for oral use. Drug Development of

Industrial Pharmacy 1984;10:313-39.

Moes AJ. Gastroretentive dosage forms. Crit Rev Ther Drug Carrier Syst


Deshpande A, Rhodes CT, Shah NH, Malick AW. Controlled-release drug

delivery systems for prolonged gastric residence: An overview. Drug

Development of Industrial Pharmacy 1996;22:531-9.

Whitehead L, Fell JT, Collett JH, Sharma HL, Smith AM. Floating dosage

forms: An in vivo study demonstrating prolonged gastric retention.

J Control Release 1998;55:3-12.

Talukder R, Fassihi R. Gastroretentive delivery systems: A mini review.

Drug Dev Ind Pharm 2004;30:1019-28.

Rouge N, Leroux JC, Cole ET, Doelker E, Buri P. Prevention of the sticking tendency of floating minitablets filled into hard gelatin capsules. Europian Journal of Pharmaceutics and Biopharmaceutics 1997;43:165-71.

Sato Y, Kawashima Y, Takeuchi H, Yamamoto H. In vivo evaluation

of riboflavin-containing microballoons for floating controlled drug

delivery system in healthy human volunteers. Journal of Controlled

Release 2003;93:39-47.

Kawashima Y, Niwa T, Takechi H, Hino T, Itoh Y. Hollow microspheres

for use as floating controlled drug delivery systems in the stomach.

Journal of Pharmaceutical Sciences 1992;81:135-40.

Soppimath KS, Kulkarni AR, Rudzinski WE, Aminabhavi TM.

Microspheres as floating drug-delivery systems to increase gastric

retention of drugs. Drug Metab Rev 2002;33:149-60.

Muthusamy K, Govindarazan G, Ravi TK. Preparation and evaluation

of lansoprazole floating micropellets. Indian Journal of Pharmaceutical

Sciences 2005;67:75-9.

Thanoo C, Sunny MC, Jayakrishnan A. Oral sustained-release drug

delivery systems using polycarbonate microspheres capable of floating

on the gastric fluid. J Pharm Pharmacol 1993;45:21-4.

Joseph NJ, Lakshmi S, Jayakrishnan A. A floating-type oral dosage formfor piroxicam based on hollow polycarbonate microspheres: In vitro and in vivo evaluation in rabbits. J Control Release 2002;79:71-9.

Stithit S, Chen W, Price JC. Development and characterization of buoyant theophylline microspheres with near zero order release kinetics.

J Microencapsul 1998;15:725-37.

Lee JH, Park TG, Choi HK. Development of oral drug delivery system

using floating microspheres. J Microencapsul 1999;16:715-29.

Gladiziwa U, Klotz U. Pharmacokinetics and pharmacodynamics

of H2 receptor antagonists in patients with renal insufficiency.

Clin Pharmacokinet 1993;24:319-32.

Struebel A, Siepmann J, Bodmeier R. Multiple units gastroretentive

drug delivery systems: A new preparation method for low density

microspheres. J Microencapsul 2003;20:329-47.

The United States Pharmacopoeia. 24th ed. Vol. 1. United States

Pharmacopoeial Convention. Rockville: 2000. p. 1941-3.

Singh N, Kim KH. Floating drug delivery systems: An approach to

oral controlled drug delivery via gastric retention. J Control Release


Dinarvand R, Mirfattahi S, Atyabi F. Preparation, characterization and

in vitro drug release of isosorbide dinitrate microspheres. Journal of

Microencapsulation 2002;19:73-81.

Abrol S, Trehan A, Katare OP. Formulation, characterization, and

in vitro evaluation of silymarin-loaded lipid microspheres. Drug Deliv




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