topical delivery

Over the past decade, numerous limitations of conventional dosage forms had attracted researchers to find a rational and appropriate drug delivery system. Microsponges were developed and studied as a novel programmable delivery system which is intended to deliver drug in controlled release pattern. It also aims epidermal localization of topical drug therapy to reduce their side effects by limiting systemic absorption through skin. Drug loaded microsponges are microporous beads, typically 10-25 µm in diameter which can entrap a wide variety of actives and can be formulated as creams, lotions, gels, ointments, powders, soaps. Microsponge formulations can increase product stability, enhance aesthetic qualities, and provide formulation flexibility and stability. Moreover, their non-antigenicity, non-toxicity, non-mutagenicity and non-biodegradability make them favourable candidates. Microsponge approach has also been applied in oral therapy, bone, tissue & cartilage engineering and showed remarkable results. This article provides description about the nature of microsponges, their characteristics, preparation, applications and commercial market status globally.

  Due to the lower risk of systemic side effects topical treatment of skin disease appears favourable, yet the stratum corneum counteracts the penetration of xenobiotics into viable skin. Particulate carrier systems may mean an option to improve dermal penetration. Since epidermal lipids are found in high amounts within the penetration barrier, lipid carriers attaching themselves to the skin surface and allowing lipid exchange between the outermost layers of the stratum corneum and the carrier appear promising. Besides liposomes and niosomes, ufasomes have been tested for their potential topical/transdermal delivery. Unsaturated fatty acid vesicles (ufasomes) are suspensions of closed lipid bi-layers that are composed of fatty acids, and their ionized species (soap) which are restricted to narrow pH range from 7 to 9. In ufasomes, fatty acid molecules are oriented in such a way that their hydrocarbon tails are directed toward the membrane interior and the carboxyl groups are in contact with water. The advantage of ufasomes over liposomes is the ready availability and lower cost of fatty acid. In this review special focus is laid upon the interactions of active ingredients and the lipid matrix as well as the quantification of dermal penetration. Key words: ufasome, topical delivery