Formulation optimization of sterilized xanthones-loaded nanoemulgels and evaluation of their wound healing activities

Xanthones (XTs) are bioactive compounds found in mangosteen trees (Garcinia mangostana Linn.). They are used as an active ingredient in various health products. However, there is a lack of data of their application in wound healing. In particular, the topical products of XTs for wound healing; they should be sterilized to minimize the risks of wound infection from contaminated microorganisms. This study thus aimed to optimize the formulation of sterilized XTs-loaded nanoemulgel (XTs-NE-G) and to investigate their wound healing activities. The XTs-NE-Gs were prepared by mixing various gels containing sodium alginate (Alg) and Pluronic F127 (F127) into a XTs-nanoemulsion (NE) concentrate according to the face-centered central composite design. The results showed that the optimized XTs-NE-G was A5-F3 containing 5% w/w Alg and 3% w/w F127. It enhanced the proliferation-, migration rates of skin fibroblasts (HFF-1 cells) with an optimal viscosity. After blending the XTs-NE concentrate and the gel that was previously sterilized by a membrane filtration and an autoclaving technique, respectively, the sterilized A5-F3 was obtained. The sterilized A5-F3 still had effective bioactivities towards the HFF-1 cells. It promoted re-epithelialization, collagen deposition and inflammation suppression in the mice’ wounds. It could thus be accepted for further investigation in clinical studies.