Title: FORMULATION AND EVALUATION OF SIMVASTATIN GASTRORETENTIVE DRUG DELIVERY SYSTEM USING NATURAL POLYMERS
Author(s): Thakur, R.P. Yadav, Z. Qureshi, S. Khatri and M.A. Khan
Gastro retentive drug delivery system is also known as novel drug delivery system. They have controlled delivery of drugs which continuously releasing the drug for a prolonged period of time. These are includes floating system, swelling and expanding system, bio/mucoadhesive system, high density system and other delayed gastric emptying device. The main concepts used to design pharmaceutical dosage forms with prolonged gastric residence times. The objective of this work was to formulate and evaluate floating drug delivery system of simvastatin by using natural polymer to modify its pharmacokinetic profile. The various floating microsphere (FF1 – FF8) was prepared by non aqueous solvent evaporation method by using various concentrations of the natural polymer chitosan and sodium alginate. The prepared microspheres were characterized for various parameters like rheological properties, floating behavior, SEM and entrapment efficiency. Floating microspheres were successfully prepared by modified solvent evaporation technique. Microsphere showed passable flow properties. The % yield of microspheres was up to 65-81 %. Mean particle size was found to be in the range 650-1034µm. Entrapment efficiency of different formulations were in the range of 63.50-86.00%. In dissolution medium the swelling property was found in the range of 14.5-19.9%. The cumulative drug release was observed to be in the range of 34.380-66.363%. On the basis of result, it can be concluded that the microspheres produced from chitosan and sodium alginate by using non-aqueous solvent evaporation method is an excellent delivery system that has good release behavior for actively releasing drug in the stomach due to its gastro-retentive (floating) ability and therefore, this system would provide a safe and effective strategy for treatment of ulcers of the stomach or other diseases of the gut.
KEYWORDS: Gastro retentive drug delivery system (GRRDS), Simvastatin, Polymers, Floating microspheres, Drug release.