Caracterização, Desenvolvimento e Validação de Método Analítico para Determinação de Pirroloquinolina Quinona em Formulações Orais e Injetáveis de Uso Humano

Abstract

Pyrroloquinoline quinone (PQQ) has attracted increasing scientific and commercial interest due to its antioxidant, anti-inflammatory, and neuroprotective properties, and is often marketed as a dietary supplement. Given the scarcity of studies focused on the physicochemical characterization of the raw material and the validation of specific methods for its quantification, this study aimed to develop and validate a simple, fast, and efficient spectrophotometric method for the determination of PQQ in pharmaceutical formulations for oral and injectable use. Additionally, complementary analytical techniques such as FTIR-ATR, NMR, TG/DTG, DSC, and XRD were employed to characterize the substance. The proposed method showed linearity in the range of 5.0 to 25.0 µg/mL (r > 0.9999), with limits of detection and quantification of 0.12 and 0.36 µg/mL, respectively. Precision and accuracy were within the recommended limits, with RSD < 1.9% and recovery between 98.0% and 102.0%. Selectivity was confirmed by the absence of interference from common excipients. The method also proved to be robust against experimental variations and was successfully applied to the analysis of commercial samples. These results confirm the applicability and reliability of the proposed method, contributing to the quality control and safety of dietary supplements containing PQQ. Keywords: PQQ; method validation; UV-vis spectrophotometry; physicochemical characterization; dietary supplements.