A study of sulfadimidine-beta-cyclodextrin mixtures

A physical mixture and a kneaded product containing sulfadimidine and beta- cyclodextrin were prepared. The morphology of these products and of the sul fadimidine bulk substance were studied by scanning electron microscopy (SEM ). The thermoanalytical behaviour of the samples was investigated. The exis tence of an inclusion complex in the products could not be proved. However an increase in dissolution rate was observed. The reason in the case of the physical mixture lies in the regular distribution of the active agent crys tals and the beta-cyclodextrin crystals, and in the case of the kneaded pro duct in the formation of new recrystallized particles.