Avaliação da eficácia de conservante natural em um protetor solar utilizando extrato de planta medicinal do semiárido brasileiro

Abstract

Schinopsis brasiliensis Engler; Aspidosperma pyrifolium Mart., Punica granatum L. and Poincianella pyramidalys (Tul.) L. P. Queiroz are plants present in the Caatinga with potential therapeutic and cosmetic use. The objective of this work was to obtain and phytochemically characterize the extracts of the four species, quantifying total polyphenols, flavonoids, condensed tannins and saponins. Based on this result, the brauna leaf extract was chosen because it has higher concentrations of flavonoids and polyphenols. Four gel formulations containing S. brasiliensis extract were developed, the first containing extract (I), the second with extract+preservative (II), the third with preservative only (III), and the last without extract and preservative (IV), in order to investigate the preservative potential of S. brasiliensis, and its potential photo-protective effect. For the research of contaminating pathogens, the deep sowing technique was followed, according to the method described by the Brazilian Pharmacopoeia, in order to determine the preservative potential of the nebulized extract of S. brasiliensis. When observing the microorganism Escherichia coli, there was a reduction in Log10 (CFU/g) from 7.69 to < 1, exerted by the antimicrobial potential of the extract present in formulation I, proving its antimicrobial action. The physical-chemical tests were carried out using techniques to determine spreadability, centrifugation, thermal stress, thermal analysis and organoleptic characteristics. There were no changes in visual aspects such as phase separation and lump formation. In the parameters used, such as pH, the values remained in an ideal range between 5.5 and 7. The DSC traced thermal profiles related to the thermal decomposition of samples from the freeze-thaw cycle, in which characteristic endothermic peaks were found that may be related to the loss of volatile constituents of the sample, such as water and etanol. For S. brasiliensis leaf, the results of the quantification of flavonoids and total polyphenols were in evidence, in concentrations of 70.03 and 386.75, respectively. The SPF of the formulations showed satisfactory values, with SPF 16 referring to formulation I, which can be evidenced, as it is closely related to the presence of brauna extract in this formulation, which explains this photoprotective potential. The extract of S. brasiliensis analyzed in the formulations showed antimicrobial behavior, further confirming its preservative potential. Thus, the viability of using a plant resource from the caatinga as a preservative agent in a cosmetic photoprotective formulation was demonstrated.