Preparation and Characterization of Microwave-assisted Candesartan Cilexetil Solid Dispersions

The aim of the present study was to enhance the solubility & dissolution rate of a poorly soluble, BCS class II drug candesartan cilexetil (CC), using its solid dispersions (SDs) with polyethylene glycol (PEG) 6000 & hydroxypropyl methylcellulose (HPMC) E5. Solid dispersions were prepared by melting, solvent evaporation & microwave method. The dispersions were evaluated for various  in vitro  parameters such as solubility study, dissolution study, fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), X-ray powder diffraction (XRD) & scanning electron microscopy (SEM). Solubility & dissolution rate of CC was significantly higher in microwave assisted solid dispersions in comparison with pure drug, melting & solvent evaporation generated solid dispersions. Results of DSC, XRD and SEM study showed transformation of crystalline form of CC to amorphous form in microwave assisted solid dispersions. Thus, microwave technology offers a simple, efficient, solvent free promising alternative method to prepare solid dispersion of CC with significant enhancement of the solubility & dissolution rate. Keywords: Microwave, candesartan cilexetil, solubility, dissolution rate