Desenvolvimento de gel vaginal fitoterápico baseado em manteiga de Astrocaryum murumuru Mart contendo óleorresina de Copaifera reticulata Ducke para o tratamento de vaginose

Abstract

Copaiba is a plant widely used in Amazonian folk medicine, studies have evidenced several biological activities, mainly antimicrobial. However, scientific evidence is still needed about the phytotherapic use. The aim of this work was to develop a liquid-crystalline phytotherapic vaginal gel based on butter extracted from the oleaginous species Astrocaryum murumuru Mart containing oil-resin of Copaifera reticulata Ducke, for the treatment of bacterial vaginosis. The copaíba oil-resin (ORCR) was collected in the Tapajós National Forest and its chemical composition was analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). The antibacterial activity of the ORCR was performed by the disc diffusion technique and the minimum inhibitory concentration (MIC) by microdilution against strains related to vaginosis. Five formulations with fixed amount of surfactant, and different proportions of water, murumuru butter and ORCR (50, 100, 250 and 500mg/g) were obtained. After 24 hours of preparation, all formulations were subjected to polarized light microscopy in order to characterize the liquid-crystalline phase. The antimicrobial activity of the formulations was evaluated by agar well diffusion test. Afterwards, the accelerated stability study was carried out under different storage conditions (25 and 45ºC ±2ºC), where the influence of antibacterial activity and the optical properties was evaluated. In the chemical composition of the ORCR, the following majorities were determined: β-Cariophylene 32.43%, β-Bisabolene 11.28% and α-Humulene 8.41%. In the disc diffusion test the strains of Gardnerella vaginalis and Staphylococcus Epidermitidis were the most sensitive to the ORCR, presenting a MIC of 500 μg/mL, with bacteriostatic activity. After 24 hours of preparation, only the formulations containing 100 mg/g and 50 mg/g of ORCR showed cylindrical textures, characteristic of liquid-crystal of hexagonal phase structure. The formulations containing 100 mg/g and 50 mg/g of ORCR showed antimicrobial activity against all tested strains, the higher the ORCR concentration in the formulations, the higher the inhibition halos. During the 60 days of the accelerated stability study in different storage conditions no significant changes in the organoleptic characteristics of the formulations were observed, in addition, there was no disintegration of the hexagonal phase. However, the formulations stored at 45°C±2ºC showed a decrease in antimicrobial activity from the 30th day. Therefore, all results showed the formulation F6-M55A05 containing 100mg /g of ORCR as a potential candidate for clinical use as a topical liquid-crystalline phytotherapic gel for the treatment of vaginosis.