Abstract

FORMULATION AND EVALUATION OF MULTI-LAYER MATRIX TABLETS OF ANTIHYPERTENSIVE DRUG CAPTOPRIL

Ghanshyam Yadav*, Mayank Bansal, Prem Shankar Mishra, Nishi Thakur, Pragati Khare

Abstract

The present study is carried out to formulate and evaluate multi-layer matrix tablets using hydrophilic polymer, xanthan gum and chitosan as carrier and xanthan gum as retardant in multilayer tablets. Captopril was choosen as a model drug because of its higher water solubility. Matrix tablets were prepared by wet granulation technique using PVP as a binder. Multi-layer matrix tablets of captopril were prepared by compressing on both side of the core granules containing drug with 200mg of xanthan gum granules containing 65% of xanthan gum as release retardant layers. The multi-layer matrix tablets were evaluated for hardness, thickness, friability, drug content uniformity and were subjected to invitro drug release studies. The properties of the polymer used and the structure of each formulation appear to considerably affect drug release and its release rate. The multilayer matrix formulations exhibit lower drug release compared to matrix alone. This was due to the fact that the barrier-layers hindered the penetration of liquid into the core. The mean correlation co-efficients with all matrix formulations for first order release kinetics were found slightly higher when compared to those of zero order release kinetics indicating that the drug release from all the formulations followed first order kinetics. Layering with xanthan gum granules on the matrix core, provided linear drug release with zero order kinetics. FT-IR and DSC studies confirmed that there was no interaction between drug and excipients used in the formulation.

Keywords: Xanthan gum, Chitosan, Captopril, Multi-layer matrix tablets, controlled drug delivery.