Development of Curcumin loaded chitosan polymer based nanoemulsion gel: In vitro, ex vivo evaluation and in vivo wound healing studies

In the present study, various nanoemulsions were prepared using Labrafac PG + Triacetin as oil, Tween 80 as a surfactant and polyethylene glycol (PEG 400) as a co-surfactant. The developed nanoemulsions (NE1-NE5) were evaluated for physicochemical characterizations and ex-vivo for skin permeation and deposition studies. The highest skin deposition was observed for NE2 with 46.07% deposition amongst all developed nanoemulsions (NE1-NE5). Optimized nanoemulsion (NE2) had vesicle size of 84.032 ± 0.023 nm, viscosity 78.23 ± 22.2 cps, refractive index 1.404. Nanoemulsion gel were developed by incorporation of optimized nanoemulsion (NE2) into 1–3% chitosan and characterized by physical evaluation and rheological studies. Chitosan gel (2%) was found to be suitable for gelation of nanoemulsion based on its consistency, feel and ease of spreadability. The flux of nanoemulsion gel was found 68.88 μg/cm²/h as compared to NE2 (76.05 μg/cm²/h) is significantly lower suggesting limited skin permeation of curcumin form gel. However, the retained amount of curcumin on skin by gel formulation (980.75 ± 88 μg) is significantly higher than NE2 (771.25 ± 67 μg). Enhanced skin permeation of NE2 (46.07%) was observed when compared to nanoemulsion gel (31.25%) and plain gel (11.47%). The outcome of this study evidently points out the potential of curcumin entrapped nanoemulsion gel in wound healing.