Formulation and evaluation of phenytoin sodium sustained release matrix tablet

Abstract

Epilepsy is a very common disorder, characterized by seizures, which take various forms and result from episodic neuronal discharges, the form of the seizure depending on the part of the brain affected. There is no recognition cause, although it may develop after brain damage, such as trauma, infection or trauma, and other kinds of neurological diseases. Epilepsy is treated mainly with drugs, though brain surgery may be used for severe cases. Sodium channel blockers are generally used in the treatment of seizures, e.g.: phenytoin, carbamazepine, sodium valproate. The aim of this study is to develop sustained release matrix tablet of phenytoin sodium using eudragit- RL100, eudragit-RS100, HPMC-E15, ethyl cellulose (N-14), Chitosan and HPMC as release controlling factor and to evaluate drug release parameters as per various release kinetic models. The formulated tablets were also characterized by physical and chemical parameters and results were found in acceptable limits. Different dissolution models were applied to drug release data in order to evaluate release mechanisms and kinetics. Criteria for selecting the most appropriate model were based on linearity (coefficient of correlation). Based on "n" value (0.168) the drug release was follows Fickian diffusion. Also the drug release mechanism was best explained by Higuchi order (correlation value is 0.9063) by using this polymer. © 2012 Madhavi N, et al.