Analytical Method for the Simultaneous Determination of Albendazole and Metabolites Using HPLC-PDA: A Validation Study.

Albendazole is an anthelmintic drug commonly used in animals and humans against nematodes. A sensitive, accurate, precise, and time-saving high-performance liquid chromatography (HPLC) method for the simultaneous determination of albendazole and metabolites (albendazole sulfoxide and albendazole sulfone) in cattle plasma has been developed and validated. A solid-phase extraction (SPE) was carried out. Separation was performed with an XBridge^® C18 column (4.6 mm × 250 mm, 5 µm) with gradient elution of acetonitrile:ammonium acetate buffer 0.025 M with pH adjusted to 6.6. The flow rate was 1.2 mL/min, and the PDA detector was set at 292 nm. Calibration curves were linear in the range from 0.025 to 2.0 µg/mL for the three compounds evaluated, with correlation coefficients ≥ 0.99. For the lower limit of quantification (LLOQ), within- and between-run precision and accuracy were satisfactory, with coefficients of variation (CV) ≤ 15.1% and deviations ≤ 117.7%, respectively. The method fulfilled all validation criteria established by the European Medicines Agency guideline (EMA/CHMP/ICH/172948/2019).