Preparation and in-vitro evaluation of sustained release phenytoin sodium matrix tablets prepared by co-evaporation method using different polymers

Sustained-release matrix tablets of Phenytoin sodium was developed and evaluated. Tablets were prepared by co-evaporation method using hydroxy propyl methyl cellulose (HPMC), carboxymethyl cellulose (CMC) and polyvinylpyrrolidon-K90 (PVP-K90), the hydrophilic polymers as release sustaining materials. Formulations were designed using drug to polymers ratio 1:1, 1:1.5, 1:2 with the aim to develop twice daily sustained release matrix tablets. Physical characterization of both granules and tablets were evaluated. USP dissolution apparatus I was used for the In-vitro drug release study of the tablets. Drug release data was evaluated using various models like Zero-order, First-order, Higuchi model, Korsmeyer model and Hixson-Crowell model. The resulting matrix tablets prepared with all the polymers used in drug to polymer ratio fulfilled all the official requirements for a tablet dosage form except dissolution, while HPMC with drug to polymer ratio 1:2 extend the release of the drug up to 12 hours.