Nanoemulsion loaded polymeric hydrogel for topical delivery of curcumin in psoriasis

Curcumin is a natural compound with multiple molecular targets that causes inhibition of factors involved in pathogenesis of psoriasis but low solubility and poor skin penetrability limit its efficacy. The current study aimed to increase the solubility and skin penetrability of curcumin after topical application. The curcumin nanoemulsion was optimized by low-energy emulsification method and converted into nano-emulgel using cross-linked polyacrylic acid (carbopol 934) as a gelling agent. To achieve high loading, transcutol-HP (105.40 +/- 3.84 mg/g) and acconon-MC8-2 (104.73 +/- 2.85 mg/g) were explored as potential solubilizer for curcumin. Despite the high solubility of curcumin in acconon-MC8-2, it showed physical incompatibility while transcutol-HP found to be compatible with labrafac PG being an oil system for the development of nanoemulsion in presence of tween 20 (surfactant) and solutol-HS15 (co-surfactant). The droplet size of developed formulation was 10.57 nm with low PdI (0.094) and negative zeta potential (-18.7 mV). The release of curcumin from nanoemulsion follows Korsmeyer-Peppas kinetic with fickian diffusion and exhibited 4.87-fold increase in permeation of curcumin from developed nano-emulgel. The nano-emulgel formulation exhibited quicker and early healing in psoriatic mice compared to curcumin, and betamethasone-17-valerate gel. The results showed that curcumin nanoemugel is a promising candidate for the better long-term management of psoriasis.