Abstract

The objective of present work was to develop modified release tablets of isoniazid using hydroxylpropylmethylcellulose as a release-controlling agent. The low-viscosity grade hydroxylpropylmethylcellulose, medium-viscosity grade hydroxylpropylmethylcellulose, and high-viscosity grade hydroxylpropylmethylcellulose were used to prepare the matrix tablets. The tablets, prepared by direct compression, were subjected to physical characterization and in vitro drug release studies. The in vitro drug release was carried out using USP apparatus 1 at 50 rpm in 900 ml of acidic dissolution medium (pH 1.2) for 2 h, followed by 900 ml alkaline dissolution medium (pH 6.8). The polymer type did not affect the flow of powder blend and crushing strength of isoniazid tablets. The drug release rate was strongly influenced by the type of polymer and the concentration of polymer. The viscosity grade of hydroxylpropylmethylcellulose and the drug release was inversely correlated. To analyze the release mechanism Higuchi, zero-order, first-order, Hixson-Crowell, Weibull, and Korsmeyer-Peppas model were used. The optimized formulation followed the Weibull model. The use of simplified optimization methodology is demonstrated to evolve unified mathematical model.