Understanding the Concept:
Semisolid topical formulations like cleansing creams must possess appropriate rheological properties to ensure smooth application and spreadability on the skin surface.
Excipient Functional Profiling:
• Isopropyl Myristate: A low-viscosity synthetic oil and ester emollient. It reduces the greasy feel of heavy oil-in-water or water-in-oil creams, thins the formulation, and improves spreadability across the skin, leaving a non-occlusive film.
• Ozokerite: A natural mineral wax used as a thickening agent or structuring wax to stiffen cream formulations, which reduces spreadability if used in excess.
• Stearic Acid: A fatty acid used as a structuring agent, solidifying factor, or emulsifier component that builds viscosity.
• Xanthan Gum: A hydrocolloid polymer used as a thickener and stabilizer in the aqueous phase, which increases viscosity and can limit spreadability.
Thus, Isopropyl myristate is the ideal ingredient to improve spreadability.