Abstract
The dissolution of phenytoin were studied from various phentyoin-montmorillonite combinations. Firstly, phentoin-montmorllionite combinations were obtained by precipitating phenytoin from two different solvents on to montmorillonite using drug to montmorillonite ratios. Secondly, physical mixtures of phenytoin and montmorillonite were prepared in were compressed into tablets and the dissolution rates were determined. The dissolution rates of phenytoin with the dissolution rates of the combinations. The montmorillonite increased the dissolution rate of phenyton from all the combinations to such an extent that the dissolution rates compressed well with those obtained form phenytoin sodium.
The bioavailability of phentyoin from three different phenytoin-montmorillonite mixutres were compared well the bioavailability from a phenytoin sodium capsule in four volunters. More phenytoin were absorbed from the phenytoin-montrillonite mixtures than from the phenytoin sodium. The absorption rate of phenytoin from the three different montmorillonite mixtures were fastef than from the phenytoin sodium capsule for the first hour, after administtration. After one hour the phenytoin blood levels from the phenytoin-montmorillonite mixtures started to level of to reach lower peak concentrations in plasma than that obtained from phenytoin-montmorillonite mixtures (1:1 and 1:9 ratios) was more than that absorbed form phenytoin sodium. The advantages of combining phenytoin and montmorillonite for the improvement of the bioavailability of phenytoin have clearly been demonstrated.