Preparation and characterization of polymeric microparticles loaded with Moringa oleifera leaf extract for exuding wound treatment

The aim of this study was to develop an innovative formulation, particularly useful for the treatment of exuding wounds. An extract from Moringa oleifera leaves (MOE), prepared by an eco-friendly method, was used as active ingredient. Its preliminary characterization showed that MOE is rich in quercetin-O-glucoside and quercetin-Omalonyl glucoside, responsible for the antioxidant, radical scavenging and antibacterial activities (toward Staphylococcus aureus, S. epidermidis, S. faecalis and S. pyogenes). Moreover, MOE showed the ability to stimulate keratinocytes growth. Thus, bioadhesive biocompatible polymeric microparticles loaded with such extract were developed and prepared in order to treat exuding wounds. The microparticles, obtained by spray drying, using chitosan as polymer, showed good swelling ability. This is useful to obtain the transition from microparticles to a continuous gel covering the wound, after deposition on it. This has the double function to protect the damage area and to promote the healing. The in vitro release study showed that the formed gel is able to release immediately MOE, in the first minutes after application, and to promote a sustained release within 24 h reaching an efficacious concentration against the most sensitive bacterial strains. These findings suggest that the developed microparticles represent an interesting tool for exuding wounds treatment.