Formulation Development and Characterization of Bigels Containing Curcumin for Topical Skin Delivery.

Abstract

Curcumin, a pleiotropic molecule, has been reported to modulate skin health and functions owing to its anti-inflammation, wound healing, antimicrobial, and anti-aging effects. Curcumin, a lipophilic molecule, exhibits poor skin penetration that results in decreased efficacy in treating skin diseases. In this study, a bigel containing curcumin was formulated to enhance skin deposition of curcumin. Generally, bigels are composed of hydrogel (HG) and organogel (OG) and feature the ideal characteristics of both systems. The HG contained HPMC 2% w/v, and the OG contained Span® 60, almond oil, and curcumin (0.25%) mixed in different HG:OG proportions from 90:10 to 10:90. Three ratios of HG:OG, BG50 (50:50), BG40 (60:40), and BG30 (70:30) successfully formed yellowish turbid smooth bigels. The bigels were characterized as an o/w system with microdroplet size (7.10-30.60 µm) under a microscope. All bigel formulations showed pseudoplastic behavior and had low oil leaching. Skin permeation experiments revealed that BG30 provided the highest curcumin accumulation in the stratum corneum, and viable epidermis and dermis, which was higher than the control OG for 1.61 ± 0.17 and 3.63 ± 0.89-fold, respectively. All bigels were nontoxic on the murine fibroblast cell line L929 at 62.5-1,000 μg/mL of curcumin. B30 provided the highest wound healing effect as determined by the L929 scratch assay. The % migration increased to 70.11 ± 1.11 at 24 h and to 100% at 48 h. These findings suggest that BG30 could be potentially used to deliver curcumin intended for topical applications.