Preparation and evaluation of sustained release niacin and green tea extract bilayer tablets

Abstract

The aim of present study was to formulate and evaluate the Niacin and Green Tea Extract Sustained release matrix bilayer tablets. Both the sustained release layer contains Hydoxypropylmethyl cellulose, a cellulose polymer derivative used as retardant material and Polyvinyl pyrollidone used as a binder along with other excipients like Colloidal Silicondioxide, Microcrystalline Cellulose and Stearic acid. The effects of process conditions such as flow properties of granules and physical parameters of the tablets on the characteristics of sustained release bilayer tablets were investigated. The in-vitro drug release studies were evaluated using USP-II (Paddle type), carried out in Hydrochloric acid buffer at pH 1.2 as dissolution media for two hours followed by phosphate buffer pH 6.8 as a dissolution media for ten hours. The release rate of Niacin and Green Tea Extract was around 30% in pH 1.2 after two hours and not less than 90% after ten hours in pH 6.8 followed by two hours in pH 1.2 when the drug to polymer ratio is 1:0.2.