Formulation and Evaluation of Floating Drug Delivery of an Anti-Hypertensive Drug

Nifedipine is an anti-hypertensive drug which belongs to the dihydropyridine (DHP) class of calcium channel blockers (CCBs). The drug has short half-life of 2 hours and exhibits low bioavailability (45-55%). Hence the purpose of this study is to design Floating drug delivery system so as to prolong the gastric residence time as well as the drug release. Floating hollow micro particles (Microballoons) of Nifedipine were prepared using Eudragit S100 as polymer by solvent evaporation method. The effect of variables like drug to polymer ratio and volume of solvents on the physical characteristics of micro particles was investigated. The particle size distribution of the micro particles was determined using optical microscopy. The % drug loading and % entrapment efficiency of the micro particles were estimated by UV spectrophotometry. The surface morphology
of micro particles was evaluated using scanning electron microscopy. In vitro buoyancy studies were performed in USP Type II (rotating paddle) dissolution apparatus. In vitro dissolution studies were performed in USP Type I dissolution apparatus with 0.1 N HCl (pH 1.2). Micro articles of F2 were found to demonstrate an average particle size of 227μ, prolonged buoyancy and complete drug release in 8 hours. Therefore, it can be concluded that F2 would be most suitable formulation which is likely to deliver most of the drug following oral administration.