In vitro and in vivo Evaluation of Glibenclamide using Surface Solid Dispersion (SSD) Approach

The aim of this study is to enhance the solubility of poorly water soluble drugs via the Surface Solid Dispersion (SSD) strategy using glibenclamide as a model drug. The drug was solubilized by surfactants and/or polymers then adsorbed onto the surface of extremely fine carriers to increase its surface area and to form the SSD. Characterization of SSD was carried out using differential scanning calorimetry, X-ray diffraction, infrared spectroscopy, scanning electron microscopy and in vitro drug release. F5 showed the highest drug release with r>0.99. Furthermore, both DSC and X-ray diffraction showed a decrease in the melting enthalpy and reduced drug crystallinity consequently in SSDs. However, infrared spectroscopy revealed no drug interactions with the carriers. A bioequivalence study using six male volunteers showed a significant difference (p = 0.006) between the mean Cmax estimates from F5 tablets (391.21±2.36 ng/mL) and Daonil tablets (296.3± 3.18 ng/mL). The t max was 2±0.173 h for the experimental group and 2.5±0.2 h for the control group, which suggests that enhanced solubility accelerates the absorption of the drug. The two formulas were shown to be bioequivalent due to lack of significant difference between their mean AUC0-24. The results indicate that surface solid dispersion may serve as a successful strategy for enhancing solubility of poorly water soluble drugs.