Mapping the impact of polar aprotic solvent on microstructure and dynamic phase transition in glycerol monooleate/ oleic acid system

INTRODUCTION: The impact of incorporating a polar aprotic solvent, dimethyl sulfoxide (DMSO) to glycerol monooleate (GMO)/ oleic acid (OA) system was evaluated briefly, on purpose to map its influence on gel microstructure and dynamic phase transition in controlling performance of polyene antifungal drug delivery system.
METHODS: An in-situ gelling fluid precursor system (IGFPS) exhibiting inverse lyotropic liquid crystalline (LLC) phases was developed by simple solution add- mixture method. Polarized light microscopy (PLM), small angle X-ray scattering (SAXS), Differential scanning calorimeter (DSC) and oscillatory rheological assessments were performed to ascertain microstructural modulations. The developed system was examined for minimum gelling volume, gelling time, swelling behavior, mucoadhesion, in-vitro antifungal activity and in-vitro drug release.
RESULTS: SAXS study identifies coexistence of Im3m cubic phase with HCP P63/mmc hexagonal structures. SAXS and DSC data highlight DMSO’s unique ability to work both as a kosmotropic or chaotropic solvent and to be a function of its concentration. In-vitro antifungal test results point out the concentration of DMSO to be a controlling factor in drug release and diffusion. In-vitro drug release kinetic studies reveal most of the gel samples to follow matrix model and anomalous type release as implied by Peppas model.
DISCUSSION AND CONCLUSION: Finally, the antifungal IGFPS formulated were found to have the required low viscosity, responsive sol–gel phase transition, appreciative mechanical properties and desirable antifungal effect with sustained drug release performance.