Pharmaceutical topical gel containing fraction of Stryphnodendron adstringens: validation by UV method
Stem bark extracts from Stryphnodendron adstringens inhibits the growth of Candida albicans in vitro, and are popularly used in the treatment of vaginal candidiasis. However, no report on assay methods for validation for its quality control is available. This study validated a fraction with antifungal activity and vaginal gel containing it, for quantitative determination of phenolic compounds using spectrophotometry in the ultraviolet region. The method using the Folin-Ciocalteu reaction was analyzed for linearity, specificity, quantification and detection limit, precision, accuracy and robustness. The results of the pre-validation indicated the best conditions for the dosage setting parameters as read at 760nm after 30min of reaction, using pyrogallol as reference substance. Based on statistical analysis, the method satisfies the conditions, showing that the linear model does not present error due to lack of adjustment. Furthermore, variance analysis shows that the regression is significant and lower values of parameters like standard error of slope and intercept indicated high precision of the proposed methods. Goodness of fit of the regression equations was supported by high regression coefficient values and lower calculated F-values. The spectrophotometric UV-VIS method described was validated successfully for the determination of polyphenols in topical gel. This methodology complies with the analytical application demands and to secure the reliability of the results and proved to be precise, accurate, reproducible, robust, and easy to perform.
Financial support: CNPq, Fundação Araucária, FINEP, and CAPES.