Electrosprayed chitosan microcapsules as delivery vehicles for vaginal phytoformulations

The design of novel delivery systems to treat vaginal fungal infections is a topic of high interest. Chitosan, being itself antimicrobial and having good mucoadhesive properties, is an excellent candidate as a delivery matrix for active compounds. In this work, chitosan microcapsules containing dry extracts of Argentinean medicinal plants with proved biological properties (Larrea divaricata, L. cuneifolia, L. nitida, Zuccagnia punctata and Tetraglochin andina) were developed through electrospraying and compared with conventionally used tablets containing the same extracts. Total phenolics, loading efficacy, physical properties, morphology and particle size, molecular organization, water sorption capacity, release of bioactive compounds and biological properties were assessed. The encapsulation process or the inclusion in tablets did not degrade the bioactive compounds of the extracts. The release of phenolic compounds from chitosan microcapsules was faster than from tablets. The fingerprint of released phenolic compounds from microcapsules and tablets was similar to that from the dry extracts and the antioxidant and antifungal capacity remained unchanged. The FT-IR analysis suggested interactions between the chitosan and the extracts, which explained why the microcapsules kept the integrity in slightly acidic media. Increased solubility of the extracts when incorporated in the microcapsules was seen in simulated vaginal fluid, potentially increasing the bioavailability of bioactive compounds in the vaginal environment. This work highlights the potential of the chitosan-based delivery systems for phytomedicines with antifungal and antioxidant activity to be used in vulvovaginal candidiasis.