Formulation and in-Vitro Characterization of Abacavir Sulphate Effervescent Floating Tablets

Abstract

fter oral administration of Abacavir, rapid absorption occurs from upper part of gastro intestinal tract with peak concentrations occurring at 0.63 - 1 hr after dosing. Conventional drug therapy with tablets produce relatively rapid and high peak blood levels that requires frequent administration to maintain effective range of plasma drug levels. This conventional therapy leads to reduced effectiveness with poor therapeutic management. To overcome the inadequacy of conventional therapy with tablets, floating sustained release Abacavir tablets were developed. Floating sustained release Abacavir Sulphate tablets were prepared by using direct compression method. Tablet were formulated using Ethyl Cellulose with hydrocolloids like Hydroxypropyl Methylcellulose (HPMC K4M) and Carbopol 974P as release retarding polymers, Sodium bicarbonate (NaHCO3) and Citric acid as effervescent agents. Tablets were then evaluated for various physical parameters including hardness, thickness, weight variation, friability, drug content, in-vitro buoyancy, Swelling index and Invitro gastro retentive drug release were conducted. Drug and excipient compatibility studies show that they are compatible with each other. The optimized formulation (F9) shows the hardness of 5.7kg/cm2, tablet thickness of 2.74mm, 0.45% of friability, in-vitro buoyancy was up to 6 hours and % drug release was 90.56% in 6 hours. Drug release kinetics was found to follow non-fickian diffusion. Hence, F9 is considered as optimized formulation based on invitro buoyancy and % drug release.