Case Studies for the Use of Silicone Chemistry in Topical Formulations

This report demonstrates the benefits of silicone-based polymers for enhancing pharmaceutical drug delivery to skin, by means of three independent studies. The first revealed that an anhydrous semisolid formulation with a cross-linked silicone polymer offers faster and higher skin delivery of the nonsteroidal anti-inflammatory drug ibuprofen (IBP) compared to similar formulations based on organic excipients, as well as to a commercial benchmark. The second study focused on ascorbic acid (AA), a depigmenting agent used to treat hyperpigmentation disorders. This study combined a cross-linked silicone polymer and a silicone emulsifier to develop an anhydrous glycerinin-silicone system that stabilized AA for a significantly longer time compared to a commercial benchmark. Preservation of the chemical stability of the drug was shown to have a direct impact on its depigmenting activity. The third study focused on betamethasone dipropionate (BDP), a corticosteroid used to treat itching in chronic skin disorders. This study showed that a silicone resin crosspolymer film-forming emulsion provides significantly higher substantivity than a commercial benchmark based on an oil-inwater emulsion without impacting the delivery of BDP to skin.