Phytotherapeutic laboratories require access to methodologies that guarantee quality control for their products when these items are not already registered in pharmacopeias or official monographs. As such, the present study sought to validate analytical methodologies for quantifying natural flavonoids contained in extracts of "pata-de-vaca" (Bauhinia cheilantha [Bong.] Steudel) using visible light spectrophotometry and a rutin standard (µg/ml). All of the parameters required by ANVISA were evaluated. The specificity test revealed a maximum absorption peak at 420 nm. The methodology was considered linear and of high quantification sensitivity (2.51 µg/ml). The methodology also proved to be robust, and had high recovery levels (98.36%). The results obtained for repeatability, intermediate precision (intra- and inter-day), and reproducibility all certified the precision of the method, with values between 0.31 and 3.58%; the methodology was also considered exact (95.71-105.50%). This study demonstrated that the proposed methodology can be considered specific, precise, reproducible, exact, of low cost, and easy to perform.
Spectrophotometry; Rutin; Bauhinia cheilautha; Flavonoids; Phytotherapics
