The use of spray freeze drying for dissolution and oral bioavailability improvement of Azithromycin

Azithromycin is a poorly water-soluble drug with a low bioavailability. The main purpose of this investigation was to increase the solubility and dissolution of Azithromycin by the preparation of its solid dispersions, using the spray freeze drying (SFD) technique. The physicochemical properties of solid dispersions and interactions between the drug-polymer were evaluated using UV-Vis, FT-IR, DSC and PXRD. The surface morphology of the samples was observed by SEM. In order to carry out an assessment of the drug released, the dissolution test was performed. The in vitro drug released profiles were studied and it was found that the dissolution rate of the solid dispersion SFD sample (SFD-SD) was higher than the intact drug. In addition, the saturation solubility of the SFD-SD was significantly higher than the pure drug. The FT-IR spectra showed there was no chemical incompatibility between the drug and polyvinyl alcohol (PVA). The DSC thermograms revealed no possible physical interaction between the drug and the carrier. The surface morphology of samples showed the amorphous state and the distribution of the drug within the carrier particles. The dissolution of the SFD-SD formulation was increased up to 8.9 times more than pure drug utilizing the SFD technique. (C) 2017 Elsevier B.V. All rights reserved.