ABSTRACT:
The objective of this study was to develop an oral microemulsion formulation of the antihypertensive drug to enhance its bioavailability. The microemulsions were formulated by using Tween 20 as a surfactant, PEG 400 as co-surfactant and peppermint oil. Excipient ratio i.e. surfactant: co-surfactant ratio was kept 2:1, 3:1, 5:1. Microemulsions were characterized by particle size analysis and viscosity, after applying an experimental design. The formulation containing less surfactant: co-surfactant and less oil possessed less particle size and less viscosity. On the basis of appropriate parameters, formulation F7 was selected as an optimized batch optimized batch F7 was analyze for in vitro drug release study, zeta potential, physical stability. Batch F7 shows negative zeta potential which assures a good physical stability of the formulation. Dissolution study was carried out in 0.1 N HCl pH 1.2, and phosphate buffer pH 7.4% Drug release at 24 h for microemulsion formulation in the 0.1 N HCl pH 1.2, and phosphate buffer pH 7.4 was found to be 91.32% and 92.44% respectively, i.e. almost 90% release at all pH conditions within 24 h. So it was concluded that pure drug require maximum time for compete drug release than Microemulsion. Physical stability study of optimized batch F7 was carried out for 1 month. It was concluded that no change in formulation was observed after 1 month and observed for the change in Physical appearance, pH, average Particle size, and Zeta potential. It was observed that there was no change in the physical appearance Furthermore, there was no significant change observed.