Dissolution Properties and Bioavailability of Phenytoin from Ground Mixtures with Chitin or Chitosan

Abstract

With a view to application of chitin and chitosan to pharmaceutical preparations, the dissolution and bioavailability of ground mixtures of phenytoin with chitin or chitosan were investigated. Ground mixtures of phenytoin with chitin, chitosan and crystalline cellulose in 1: 2 weight ratio were prepared by co-grinding in a ball mill. The X-ray diffraction patterns suggested that the size of crystals of phenytoin was decreased in the ground mixtures. The dissolution rate of phenytoin from the ground mixtures was significantly greater than that from physical mixtures or intact phenytoin powder. The ground mixture with chitosan showed fastest dissolution, followed by that with chitin and then that with crystalline cellulose. The dissolution of phenytoin from tablets of the ground mixture with chitin or chitosan was greater than that from tablets of the physical mixture, while that from tablets of the ground mixture with crystalline cellulose was significantly smaller than that from tablets of the physical mixture. It was confirmed that the ground mixture of phenytoin-chitosan gave enhanced bioavailability of phenytoin in beagle dogs. © 1983, The Pharmaceutical Society of Japan. All rights reserved.