Development and validation of HPLC method for veterinary antiprozoals; selamectin, doramectin and fenbendazol

A reliable and selective liquid chromatography–ultraviolet detection method for determination of antiprotozoals (selamectin, doramectin and fenbendazol) has been described. HPLC separation of active constituents was achieved on various C18 columns using methanol, acetonitrile, 0.1% phosphoric acid, acetic acid and distilled water as mobile phase, with UV detection at 243, 245 and 224 nm. The analytical procedure has been successfully identified. The method was validated for specificity, linearity, accuracy, repeatability and intermediated precision. All calibration curves showed good linearity (R 2 of 0.9999) within the concentrations ranges (0~200, 0~200 and 50~400 μg/mL). The accuracy and repeatability showed 99%, 100%, 100% and below 0.4%, 0.5%, 0.6%, respectively. The precision tests conducted for 3 days in three different concentrations with standard also revealed below 3.5%, 2.4% and 2.7%. The method has also been applied successfully to monitor post-market 5 veterinary products of which active ingredient are selamectin, doramectin and fenbendazol. There were no non-compliant products.