Polyoxyethylene Sorbitan Monostearate, an ester derived from the saturated fatty acid stearic acid (C18:0), serves multiple roles in pharmaceutical formulations, including as a surfactant, emulsifier, solubilizer, and wetting agent. As a pharmaceutical excipient—an inert substance that enhances the stability, solubility, and processability of drug formulations—it plays a crucial role in affecting the absorption, distribution, metabolism, and elimination (ADME) processes of drugs [1] [2].