Tyrosinase inhibitor-loaded microsponge drug delivery system: new approach for hyperpigmentation disorders

Objective: The aim of the present investigation was to design and formulate appropriate form of glabridin, using microsponge drug delivery system. Method: Microsponges were prepared by emulsion solvent evaporation method and characterized by drug loading, infrared spectroscopy and scanning electron microscopy. In?vitro diffusion studies of gel formulation were performed using ethanol: phosphate buffer (1:1) mixture as receptor medium. Animal studies were carried out using brownish guinea pigs with UV-induced pigmentation model. Results: Prepared microsponges were predominantly yellowish, free-flowing and spherical in shape. The infrared spectra revealed the absence of drug polymer interaction. Scanning electron microscopy (SEM) and porosity studies confirmed spherical and porous nature. In?vitro release studies data depicted highest correlation with Higuchi treatment. Animal studies also supported the better depigmenting activity as compared to plain gel. Conclusion: Glabridin microsponge-loaded gel could be efficacious in treating various hyperpigmentation disorders.