Abstract

COMPARATIVE STUDY ON THE DISSOLUTION PROFILES OF COMMERCIAL MODIFIED RELEASE FORMULATIONS OF NIFEDIPINE

Rajni Bala* and Kamaldeep Singh

Abstract

A controlled release formulation of Nifedipine (NF) was developed on modified pharmacokinetic principles where time of delivery is longer than dosing interval (Sood, 2001). Dissolution profile of NF was compared with all modified release formulations (Test) marketed in India. USP apparatus II (paddle type) at 50 rpm was employed to perform dissolutions studies. Phosphate buffer at pH 6.8 containing 1% w/v sodium lauryl sulphate (SLS) was used as dissolution medium. Samples were withdrawn at different time points over a period of 24 hours and percentage release of drug was calculated. The factor f2 of Food and Drug Administration (FDA)’s guideline was applied for qualitative determination of similarity between pair dissolution profiles. Results indicated that no test formulations were similar to NF formulation (f2 below 50). In order to show pharmacokinetic advantage of NF formulation over other, three best formulations were selected (based on similarity factor) and further subjected to dissolution testing at different pH. Along with NF formulation, all selected test formulations showed pH independent release (f2 above 50). Finally, in vivo performance of all selected formulations were predicted and compared with in vivo performance of NF formulation.

Keywords: Nifedipine (NF), sodium lauryl sulphate (SLS).