Systematically Optimized Imiquimod-Loaded Novel Hybrid Vesicles by Employing Design of Experiment (DoE) Approach with Improved Biocompatibility, Stability, and Dermatokinetic Profile.

The present research work explored the possibility of harnessing the benefits of vesicular carriers for overcoming imiquimod-associated complaints or side effects. Hybrid vesicles were prepared by the most common and easily scalable method, i.e., thin film hydration. The chaffing of myriad of factors, both process and material related, affecting the desirable attributes of conceived vesicles, was performed through Taguchi design. Based upon the analysis of Pareto chart and prior experiences, concentration of phospholipid and poloxamer 407 was selected for optimization by 2 levels, 13 run central composite design (CCD). The optimized hybrid vesicles contained 1% w/v phospholipid and 3% w/v poloxamer 407. The optimized hybrid vesicles were incorporated into the 3% w/v carbopol 940 gel and characterized for morphology, physicochemical properties, and rheological behavior. The release (%) and skin retention (% of total dose) across rat skin from gel at same amount of formulation was more than Imiquad®. The gel delivered the loaded cargo, preferably, in the viable region of skin and formed local depot in confocal microscopic studies. The gel followed one compartment open body dermatokinetic model in rat skin. There was not any harmful effect on the mice skin after repeated applications. The gel was stable at room conditions for 1 year.