INCLUSION COMPLEXATION OF TOLBUTAMIDE WITH BETA-CYCLODEXTRIN AND HYDROXYPROPYL-BETA-CYCLODEXTRIN

Inclusion complexes of tolbutamide with beta-cyclodextrin and hydroxyp ropyl-beta-cyclodextrin were prepared using different methods: kneadin g, coprecipitation and freeze-drying. Inclusion complexation in aqueou s solution and in solid phase state was studied by the solubility meth od, X-ray diffractometry, thermal analysis and Raman spectroscopy. The solubility of tolbutamide increased as a function of cyclodextrin con centration, showing B-S and A(L) type diagrams for beta-cyclodextrin a nd hydroxypropyl-beta-cyclodextrin, respectively. The dissolution rate of tolbutamide/cyclodextrin complexes were investigated and compared with those of the physical mixtures and pure drug. The dissolution rat e of tolbutamide from the inclusion complexes was much more rapid than tolbutamide alone.