Development of a sunscreen by thermal compatibility study using Schinopsis brasiliensis Engler extract as preservative

Extracts of medicinal plants are the starting point for the development of drugs and/or cosmetics obtained as plant active pharmaceutical ingredient. In the development of a pharmaceutical product is necessary the physical-chemical study of the formulation candidate, which will aim to provide possible incompatibilities between the active ingredients and excipients, which can affect the final product. This study was an important step in the development of sunscreen, because it identified, among other characteristics, problems related to the excipient, and the stability of the formulation. Thus, the aim of this work was to evaluate the compatibility study to develop a sunscreen using Schinopsis brasiliensis Engler extract as a preservative. The extract was obtained by spray dryer, and binary mixtures were produced with the excipients used in the production of a sunscreen, which were analyzed by differential scanning calorimetry with temperature range from 25 to 400 A degrees C and heating rate of 10 A degrees C min(-1). In thermogravimetry the experiments were programmed at the temperature range from 25 to 900 using a heating rate of 10 A degrees C min(-1). Infrared and Fourier transform spectroscopy was recorded using KBr stressed disks in the range of 4000-500 cm(-1). The results showed evidence of incompatibility between the extract and carboxymethylcellulose, hydroxyethyl cellulose, glycerin, sorbitol, sodium bicarbonate and calcium carbonate. With the results obtained were selected the excipients that weren't incompatible with the extract. Thus, the formulation was produced with Carbopol 940, propylene glycol, triethanolamine, octyl methoxycinnamate and S. brasiliensis Engler extract as preservative.