Preparation and evaluation of topical nanoformulations for treatment of melasma

Abstract

An excess of melanin level in skin leads to an aesthetically undesirable skin disorder known as melasma, resulting in a wide search for effective treatments. Nevertheless, the aggressiveness of physical treatments, such as cryotherapy, chemical peels and laser therapy have shed thelights on the importance of topical treatments, in which the skin whitening agents have been considered. In fact, a multi-therapy approach is needed in most cases of hyperpigmentation. However, the poor chemical stability of the majority of whitening agents and the need to enhance their skin bioavailability have been the major concern of several studies focusing on nanocarrier systems as potential protectors. Recent research has demonstrated that using whitening agents in nanocarrier systems as a therapeutic approach is very promising for treatment of melasma.

Arbutin is a naturally occurring Beta-D-glucopyranoside derivative of hydroquinone, existing in the dried leaves of bearberry. Arbutin is widely used as a skin whitening or depigmenting agent as it acts by inhibiting melanosomal tyrosinase, which is the main cause for skin hyperpigmentation disorder. There are two isomeric forms for arbutin, alpha and beta isomers. Studies have shown that alpha-arbutin possesses an even stronger inhibitory effect on human tyrosinase activity as well as better stability compared to the beta isomer.