Resveratrol-Loaded Microsponge Gel for Wound Healing: In Vitro and In Vivo Characterization

The study was aimed to formulate resveratrol (RSV) loaded microsponges to deliver drug at the wound site and incorporate it in the Moringa oleifera Lam. (Moringaceae) gel base to provide an appropriate moist environment for wound management. RSV, a stilbenoid that activates sirtuins and cell-signaling regulators involved in the process of wound healing.

Microsponges were prepared by oil in oil emulsion solvent diffusion method by optimizing the independent variables; drug: polymer ratio and volume of internal phase solvent and their effects on entrapment efficiency and particle size. Formulation batches were evaluated for drug content, production yield, entrapment efficiency, and in vitro drug release. The microsponges were further incorporated into M. oleifera gum gel, which was then evaluated for spreadability, viscosity, ex vivo diffusion study and in vivo studies using an excision wound model in rats.

Scanning electron microscopy revealed spherical and porous nature of the microsponges in vitro-release study of the optimized batch of RSV microsponges showed 80.88% drug release within 8 h. Differential scanning calorimetry results revealed no drug and polymer interaction during the formation of microsponges. An ex vivo diffusion study through goat skin revealed sustained release of RSV through porous microsponges embedded in the gel base at the wound site. An in vivo study performed using an excision wound model showed wound healing and closure within day 8. Histopathology showed increased re-epithelization and reduced ulceration in RSV microsponge gel-treated group compared with sham operated.

RSV microsponge gel delivered the drug at the wound site and the gel base provided a moist environment and influenced cell adhesion, thereby promoting faster wound healing.