ABSTRACT
Inclusion complexes of nicardipine HCl [NIC] with beta-cyclodextrin [beta-CD] and hydroxypropyl-beta-cyclodextrin [HP-beta-CD] were prepared using different methods: co-evaporation, kneading and co-precipitation. Inclusion complexation in aqueous solution and in solid state was studied by the solubility method, Fourier transform-infrared spectroscopy [FTIR], Differential scanning calorimetry [DSC] and X-ray diffractometry [XRD]. The solubility of [NIC] increased as a function of cyclodextrin concentration, showing B s and AL type diagrams for [beta-CD] and [HP-beta-CD], respectively. The dissolution rate of [NIC] / cyclodextrin complexes were investigated and compared with those of the physical mixtures and pure drug. The dissolution efficiency of [NIC] increased by complexation with cyclodextrins to 2.8-2.9 fold than [NIC] alone. Oral bioavailability in rabbits increased to 6 fold by complexation with [beta-CD]