Pharmaceutical Evaluation of Change of Phenytoin Dosage Form from Powder to Fine Granule

Abstract

Phenytoin (PHT) fine granule, which has the same bioavailability as the tablet, has recently been marketed. We projected a change of PHT dosage form from usual powder to fine granule. In view of the fact that 97% of PHT products prescribed and marketed are available in fine granules, 50% PHT preparations were produced in hospital pharmacy. 5 kinds of preparations using various lactoses as diluents were prepared and tested for their quality. Among them, the preparation from Aleviatin fine granule passing through a 42-mesh sieve and EFC lactose showed the best results in the mixing property and various sense tests. The change to this dosage form and its bioavailability tests were carried out by a cooperation of doctors and pharmacists. Serum PHT levels of all patients, assayed by EMIT method, showed a 20% to 30% increase after the administration of the new preparation (50% PHT fine granule with EFC lactose).