Role of Stearic\nAcid toward the Gelation of Cocoa\nButter and Wheat Germ Oil-Based Oleogels: Preparation, Physical Properties,\nand Application in Topical Mupirocin Delivery

Oleogel (OG) is one of the popular sources of unsaturated\nfatty\nacids that replace hazardous saturated fatty acids, synthesized by\nstructuring edible oils using gelators. In our present investigation,\nwe prepared OGs by varying the ratios of cocoa butter (CB), wheat\ngerm oil (WGO), and a fixed amount of stearic acid (SA) for topical\ndrug delivery application. The critical gelation concentration of\nCB in WGO was found to be 3% (w/w) in the presence of 7.75% (w/w)\nSA. Various characterization techniques were employed for the developed\nOGs, including bright-field and polarized light microscopy, crystallization\nkinetics, X-ray diffraction (XRD), and rheology. Micrographs captured\nby using polarized light and bright-field microscopes illustrated\nthe crystalline structure of the OGs. OGs displayed a network of needle-shaped\narrangements due to the presence of SA and CB. XRD results demonstrated\nthe formation of a β′ polymorph structure inside the\nOG and rheological data proves that the OG formulation with 20% (w/w)\n CB (OG 20) forms the strongest OG among all formulations. Moreover,\nthe crystallization kinetics was studied to observe the development\nof solid fat crystals in OGs. The in vitro release of mupirocin from\nthe OGs was best described by the Korsmeyer–Peppas and Peppas–Sahlin\nmodels, indicating that drug diffusion occurred via Fickian mechanism.\nAdditionally, OGs were investigated and explored for potential topical\ndrug delivery applications through ex vivo permeation studies.