Ensaio de degradação forçada e análise do teor de Cumarina em xarope de Cumaru (Amburana cearensis Fr All)

Abstract

Phytotherapy is the therapy that uses medicinal plants or plant derivatives, and is based on knowledge and popular use. Linked to this therapy, there are herbal products, which are those derived from the active plant raw material, and may have curative, prophylactic and palliative properties. Coumaru syrup (Amburana cearensis Fr All) 5% is a phytotherapeutic product produced by Farmácia Escola UFC that uses in its composition the hydroalcoholic tincture of the tonka bean stem bark. Some important phytoconstituents found in the stem bark include isocamppheridium, amburosides A and B, protocatechuic acid and coumarin, the latter being responsible for the peculiar odor. Coumarin is also identified as one of the main constituents responsible for the pharmacological activity of the species. Based on the hypothesis that quality control is essential for the quantification of the constituents of a herbal medicine, the present study aimed to carry out the forced degradation test of coumaru syrup and the analysis of the coumarin content by High Performance Liquid Chromatography (HPLC). Methodologically, this is an experimental study of a quantitative nature. For that, initially, a calibration curve was made for the analytical method with coumarin solutions, obtaining an R2 of 0.9999. For the forced degradation test in acidic, oxidizing and alkaline media, it was found that, in the first two conditions, there was an increase in the coumarin content in relation to the control sample, while in the last condition, no peak related to coumarin was observed in the chromatograms, indicating loss of substance. With the degradation test data in hand, kinetics of degradation were proposed for the product and, comparing the results obtained, it was concluded that the order two kinetics was the most adequate, since it had better values of R2, in addition to presenting degradation rates more consistent with expectations. Due to the results obtained, a change was also proposed in the HPLC analytical method used and evidence of linearity and precision was found, with R2 value =0.9929 and minimum values of standard deviation and relative standard deviation. In addition, physical-chemical quality control tests were also carried out for the coumaru syrup, such as substance identification, pH, viscosity, density and organoleptic characteristics, for which all the results obtained were coherent for the formulation. Thus, the present work demonstrated that it is possible to analyze the coumarin content in coumaru syrup by HPLC after exposing the product to conditions of forced degradation.