Formulation and evaluation of self nanoemulsifying drug delivery system of nifedipine

Abstract

Oral route is the most preferred route of drug administration due to its easy accessibility, intake, and wide range of choices making it economical. Currently, greater than 60% of marketed drugs are oral products. Over 90% of therapeutic compounds given orally areknown to possess oral bioavailability limitations. Therefore, there is a need to explore various approaches that can be used to improve oral drug bioavailability besides using physical and chemical means. The objective of this study is to prepare a formulation i.e. self microemulsifying drug delivery system (SMEDDS) of nifedipine with the intention to improve the increase dissolution rate (solubility). This will ensure the quick absorption and uniform bioavailability of nifedipine. Selection of oils, surfactants and co-surfactants was done by determining % transparency and on the basis of compatibility studies by FTIR spectra analysis. Different SMEDDS formulation were prepared of different ratio of oil:surfactantmix (1:9,2:8,3:7,4:6,5:5,6:4,7:3,8:2,9:1) and different ratio of surfactants : cosurfactants. Pseudo ternary phase diagram were constructed by water titration method to obtain a particle micro-emulsion region (on the basis of clarity and transparency). The formulation B-I was optimized because of maximum transparency (87.35%) and maximum % drug entrapment (95.32%). The average droplet size and zeta potential was found 86.05 and -0.189. The solubility of nifedipine increase in SMEDDS formulation upto72.17%.From in vitro dissolution study it was proved that SMEDDS formulation releases drug at faster rate, thus the objective of increase solubility and hence the better dissolution rate for uniform bioavailability via SMEDDS formulation of nifedipine was successfully achieved.