Aplicação da cromatografia líquida de alta resolução com deteção por díodos (HPLC-DAD) para a determinação de sulfadiazina e sulfadoxina no soro

Introduction. Monitoring serum drug levels in children with congenital toxoplasmosis is essential for determining therapeutic efficacy. This study aimed to standardize the quantification of two sulfonamides, sulfadiazine (SDZ) and sulfadoxine (SDX), using high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD). Key attributes such as linearity, precision, accuracy, selectivity, limit of detection (LOD), and limit of quantification (LOQ) were evaluated, alongside secondary attributes like drug stability and matrix effects. Methodology. The quantification of SDZ and SDX was performed using HPLC-DAD, evaluating: linearity: Confirmed a linear correlation between analytical signal and drug concentration, precision: Evaluated using relative standard deviation (%RSD), accuracy: Determined by recovery percentages, selectivity: Ensured no significant interference from the biological matrix, LOD and LOQ: Assessed for method sensitivity. Results. The method demonstrated a clear linear relationship between concentration and instrumental response. Precision was within acceptable ranges for bioanalytical studies, with %RSD indicating consistent results. The accuracy was satisfactory with recovery percentages slightly below 90%, which was acceptable considering the complexity of the biological matrix. LOD and LOQ were consistent with previously reported values, confirming high sensitivity. Conclusions. The HPLC-DAD method is reliable, robust, and sensitive for monitoring sulfadiazine and sulfadoxine levels in serum. While recovery percentages were slightly below 90%, the method’s performance was satisfactory considering the biological matrix. This method is suitable for therapeutic monitoring and can aid in assessing treatment efficacy in congenital toxoplasmosis.