Simultaneous determination of albendazole and praziquantel in rat plasma by HPLC-UV

A simple, sensitive and easy high-performance liquid chromatographic [HPLC] method has been developed and validated for the simultaneous estimation of albendazole [ABZ] and praziquantel [PRQ] using diazepam as an internal standard in rat plasma. Extraction of ABZ, PRQ and Diazepam in rat plasma was carried out by a process which involves precipitation of proteins called protein precipitation. Protein precipitation method was done by using 8.25% v/v perchloric acid. Chromatographic separations were performed using an Enable C18 column [250 mm × 4.6 mm, 5 μm: Spinco Biotech Pvt. Ltd]. The mobile phase consisted of acetonitrile: water [60:40, v/v] at a flow rate of 1.0 mL min^-1 at an ambient temperature for plasma samples. The above method was developed and validated over the range from 50-8000 ng mL^-1 for both ABZ and PRQ in the rat plasma. The recovery of ABZ was found to be 97.81 to 105.28%, whereas PRQ recoveries ranged from 96.80 to 102.63% in the rat plasma. Acceptable Intra-day and inter-day assay precision [<15% R.S.D.] and accuracy [<15% R.S.D.] were observed over 50–8000 ng mL^-1 for ABZ and PRQ in rat plasma. This method can be effectively applied to the pharmacokinetic study of albendazole and praziquantel in rat plasma to determine all the pharmacokinetic parameters.