Preparation of Zaleplon Microparticles Using Emulsion Solvent Diffusion Technique

Abstract

Zaleplon is a BCS class II drug suffering from poor solubility. In a trial to improve its dissolution, emulsion solvent diffusion method (ESD) was used to prepare zaleplon microparticles using sodium lauryl sulfate (SLS) as surfactant. Optimization of drug system was achieved. Particle size values of the prepared microparticles were ranged from 6.57 μm to 20.30 μm with narrow particle size distribution range. Differential scanning calorimetry (DSC) and x-ray diffraction (XRD) were used for the characterization of the prepared systems. DSC and XRD patterns showed that the zaleplon microparticles possessed decreased crystallinity. Dissolution studies demonstrated that the systemized zaleplon microparticles exhibited significantly enhanced dissolution rate when compared to pure zaleplon. A correlation could be observed between the microparticle morphology and the dissolution rate, where zaleplon microparticles that exhibited the fastest dissolution profiles had a distinctive rod shape compared to the other systems. In contrast, pure zaleplon powder appeared as irregularly-shaped particles. In conclusion, the dissolution rate of zaleplon can be enhanced to a great extent by ESD technique.