Acta Pharm. 52 (2002) 149-159
Formation of carbamazepine complexes with hydroxypropyl-beta-cyclodextrin and dimethyl-beta-cyclodextrin in solution was studied by the phase solubility method. Solid complexes were prepared using the freeze and spray drying techniques. The complexes were evaluated by the DSC analysis. Complexation led to an improvement in the dissolution rate of carbamazepine. The interfacial model system was employed to measure the transfer rate constants from the aqueous to the organic phase of carbamazepine alone or in the complex form. The observed first-order transfer rate constants showed that the complexation with cyclodextrins decreased the transport of carbamazepine from the aqueous to the organic phase. Oil in water emulsions containing carbamazepine or hydroxypropyl-beta-cyclodextrin complexes were prepared and evaluated. Comparing the release rate constants of carbamazepine from emulsions the increasing value of the release rate constants were observed when complexes were added to the formulation.
Keywords: carbamazepine inclusion complexes, hydroxpropyl-, dimethyl-beta-cyclodextrin, stability constant, transfer rate constant, o/w emulsion