In the present study, a simple, precise and accurate high performance liquid chromatography with photodiode array detector was developed for the simultaneous estimation of ivermectin & fenbendazole in bulk and tablet dosage forms. A Zorbax C8 column (250 cm × 4.6 mm × 5 μm) with mobile phase consisting of 0.1 M potassium dihydrogen orthophosphate and methanol (60:40 v/v) having pH 4.5 (adjusted with orthophosphoric acid) was used. The flow rate was 1.2 ml/min and the effluents were detected at

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... 68 nm. The retention times of ivermectin and fenbendazole were found to be at 3.296 min and 7.257 min, respectively. The linearity of the selected drugs was obtained in the range of 2-6 μg/ml (ivermectin) and 60-80 μg/ml (fenbendazole). The results of analysis have been validated according to ICH guidelines. The results for all validation parameters were found to be within the acceptance limit. Ivermectin and fenbendazole were degraded under acidic, alkaline, oxidative, thermal and photolytic degradation conditions. All the peaks of degraded products were well resolved from the peaks of ivermectin and fenbendazole. The developed and validated method can be employed as a stability-indicating, as it could efficiently separate ivermectin and fenbendazole from their degradation products.