PROCESS-INDUCED CRYSTALLITE SIZE AND DISSOLUTION CHANGES ELUCIDATED BY A VARIETY OF ANALYTICAL METHODS

The purpose of this work was the study, by multiple analytical techniq ues, of the physico-chemical changes and the dissolution behaviour of various recrystallized forms obtained through different recrystallizat ion methods. Scanning electron microscopy, differential scanning calor imetry, powder X-ray diffraction and infra-red spectroscopy were appli ed to evaluate the samples. These analytical techniques showed changes in particle morphology, and ruled out the possibility of the existenc e of polymorphs, pseudopolymorphs, totally amorphous forms or chemical structural changes. The powder X-ray diffraction technique showed gre at reductions in the drug crystallite sizes induced by both recrystall ization methods. The decreased drug crystallite sizes can explain the faster dissolution rates of the recrystallized samples as compared to the non-recrystallized drug acetylsalicylic acid (ASA), or to the phys ical mixtures of drug (ASA) and carrier (mannitol). (C) 1998 Elsevier Science B.V. All rights reserved.