Novel Topical Formulations for Hyperpigmentation: Recent Advances and Therapeutic Perspectives

Hyperpigmentation is a common skin disorder in which melanin is overproduced and accumulated leading to development of dark spots on the skin. It can be caused due to various reasons like exposure to uv rays, changes in hormonal levels-inflammatory conditions, genetic factors and skin damage. Various topical drugs like hydroquinone, kojic acid, arbutin, azelaic acid, glycolic acid, niacinamide and vitamin-C have been widely employed in the treatment of hyperpigmentation. However, they suffer from several disadvantages including low solubility, instability, low permeability and causes adverse effects like irritation and allergy. Various advancements have been made in the field of topical drug delivery systems that focus on providing stability, controlled release and permeability of the active drug. Emulgel formulation is gaining popularity as a topical formulation as it combines the advantages of both emulsions and gels, thus improving drug loading, easy spreading properties, stability and patient compliance. Advanced drug delivery systems like liposomes, nanoemulsions, niosomes, solid lipid nanoparticles and nanostructured lipid carriers have shown potential to overcome the shortcomings of conventional drug delivery systems. The present review describes the mechanism of melanogenesis, widely used depigmenting agents and its various drawbacks. Various formulations, permeation enhancers and recent advancement in topical drug delivery have been discussed in this review. Limitations and future perspectives for stable, effective and patient friendly topical formulations for the treatment of hyperpigmentation.