Preparation and Characterization of Microwave-assisted Candesartan Cilexetil Solid Dispersions

Abstract

The aim of the present study was to enhance the solubility and dissolution rate of a poorly soluble, BCS class II drug candesartan cilexetil (CC), using its solid dispersions (SDs) with polyethylene glycol (PEG) 6000 and hydroxypropyl methylcellulose (HPMC) E5. Solid dispersions were prepared by melting, solvent evaporation and 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) and scanning electron microscopy (SEM). Solubility and dissolution rate of CC was significantly higher in microwave-assisted solid dispersions in comparison with pure drug, melting and solvent evaporation-generated solid dispersions. Results of DSC, XRD and SEM studies 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 and dissolution rate.

Keywords: Microwave, candesartan cilexetil, solubility, dissolution rate