Formulation strategy for low absorption window antihypertensive agent

Abstract

In the present study a hydrodynamically balanced system of celiprolol hydrochloride was developed as single unit fl oating capsule. Various grades of low density polymers were used for formulation of this system. They were prepared by physical blending of celiprolol hydrochloride and the polymer in varying ratios. The formulation was optimized on the basis of in vitro buoyancy and in vitro release in citrate phosphate buffer at pH 3.0. Effect of various release modifi ers was studied to ensure the delivery of drug from the hydrodynamically balanced system capsule over a period of 12 h. Capsule prepared with HPMC K4 M and liquid paraffi n gave the best in vitro percentage release and was taken as optimized formulation. By fi tting the data in zero order, fi rst order and Higuchi model it could be concluded that the release followed zero order release, as the correlation coeffi cient was higher for zero order release. It could be concluded from R 2 value for Higuchi model and K-Peppas model that drug release followed fi ckian diffusion mechanism.