Abstract: Lecithin-type liposomes are stabilized with quaternized alkyated polymers, such as steardimonium hydroxyethylcellulose, to provide excellent stability for cosmetic and pharmaceutical formulations. Temperature, storage, solvent, and acidity stability are described. The stabilized liposomes can serve as vectors for alpha-hydroxy acids and showed no aggregation even after 4 months of storage at pH 2.

Abstract: A protective cosmetic particulate gel delivery system for a topically applied active agent employs an agar gel and a restraining polymer to retain the actve agent in the gel. The particles have an average particle diameter of at least 0.05 mm while the restraining polymer has a molecular weight of at least 50,000 daltons and has retention groups to bind the active agent. The restraining polymers can be selected from the group consisting of polyquaternium 24, laurdimonium hydroxyethylcellulose, cocodimonium hydroxyethylcellulose, steardimonium hydroxyethylcellulose, quaternary ammonium substituted water-soluble polysaccharides, alleyl quaternary celluloses and polypeptides having or provided with retention groups to retain the active agent. The gel particles of the invention are manually crushable on the skin to increase the surface area of the gel particle material and expose the restraining polymer to the skin or other body surface for release of the active agent.