Desenvolvimento de hidrogel mucoadesivo de uso bucal, incorporado ao insumo farmacêutico ativo vegetal de Schinopsis brasiliensis Engler., com atividade antifúngica sobre Candida albicans

Abstract

Treatment alternatives for oral candidiasis are not without failures in efficacy. Long-term therapies, increased resistance to traditional or latest generation antifungals denote therapeutic fragility. In this context, natural products emerge as an antifungal alternative, especially regarding resistance to conventional therapy. Schinopsis brasiliensis Engler, Anacardiaceae family, is the main representative species of Schinopsis genus, native to Brazil. In traditional medicine it is used for anti-inflammatory, analgesic, hemostatic, antiseptic, antibacterial, and antifungal purposes. Thus, the aim of this study was to evaluate the antifungal potential of S. brasiliensis extract on Candida albicans (C. albicans) strains, to carry out a compatibility study with mucoadhesive excipients, to evaluate the antifungal activity and to characterize mucoadhesive hydrogels for oral use. For this, the antifungal activity was evaluated in different concentrations of the hydroethanolic extract of the leaves of S. brasiliensis and a pharmacological potency assay was carried out on C. albicans (ATCC 10231). The agar diffusion technique was used, cylinder method, using 5x1 factorial design. The compatibility study was performed with binary mixtures (MB) between pharmaceutical excipients and extract in the proportions 1:1, 1:2 and 2:1. The excipients used were: carbopol, chitosan, carboxymethylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose and pluronic F127. This study used Differential Thermal Analysis (DTA), Thermogravimetry (TG) and Fourier Transform Infrared Spectroscopy (FTIR). The hydrogels formulated with the compatible excipients were characterized for pH, viscosity and mucoadhesive strength and evaluated for antifungal activity. C. albicans was susceptible to the extract at the concentrations analyzed. The pharmacological potency was superior to the chemical marker gallic acid and the concentration of the extract for the hydrogel formulation was 50 mg mL-1. The TG and DTA curves of MB of the extract with excipients maintained thermal characteristics of the extract or excipient suggesting compatibility between them. These preliminary results may contribute to the development of a phytotherapeutic drug, for treatment of oral candidiasis supplementary to conventional therapy, as well as an alternative to treat cases of antifungal resistance.