Development and characterization of a new non-aqueous self-double-emulsifying drug delivery system for topical application of rutin

Abstract

Abstract Rutin has obvious scavenging properties on oxidizing species, whereas its topical application is restricted due to its poor solubility in both water and many oils. This study aimed at development of a new non-aqueous self-double-emulsifying drug delivery system (N-SDEDDS) co-stabilized by hydrophobic bentonite and nonionic surfactants for topical application of rutin. The new formulation was prepared through a two-step process, and characterized mainly by morphology, stability, drug release, and in vitro skin permeation behavior. Apparently, the mixed-emulsifier system could significantly improve the stability of N-SDEDDS. Meanwhile, the optimized formulation also showed good self-emulsification efficiency, and upon dilution with water to form oil-in-oil-in-water (O/O/W) double emulsions. Further, the rutin-loaded N-SDEDDS displayed sustained release profile (53.79% in 12\u202fh) and was stable for 3\u202fmonths\u202fat 4\u202f°C and 25\u202f°C. Significantly higher skin permeation of rutin from N-SDEDDS (flux value 0.211\u202f±\u202f0.064 μg/(cm2 · h)) was achieved, as compared to aqueous solution (0.098\u202f±\u202f0.015 μg/(cm2 · h)). Higher magnitude of rutin retention in the skin layers was also noted with N-SDEDDS ((31.16\u202f±\u202f5.81)%) vis-a-vis aqueous solution ((20.32\u202f±\u202f3.36)%). These studies demonstrated the N-SDEDDS might be an efficient carrier for topical application of rutin which was neither water-soluble nor oil-soluble.