Oxibendazole is a type of benzimidazole that is commonly used as an antiparasitic medication for both humans and animals. However, it is also a significant impurity found in albendazole, and it is crucial to follow the ICH Q3B criteria when analysing oxibendazole impurities. Therefore, it is recommended to use a simple, fast, sensitive, and precise RP-HPLC approach to identify oxibendazole impurities in bulk and pharmaceutical formulations of albendazole.To separate the oxibendazole impurity, acetonitrile and 10 nM potassium phosphate were used as a mobile phase. Orthophosphoric acid was used to accurately adjust the pH of the mobile phase to 2.03, ensuring optimal conditions. A nucleosil C18 column (250 x 4.6 mm, 5 µm) was used for the separation process, and it effectively provided the necessary separation. The gradient elution was set at a wavelength of 235 nm and a flow rate of 1 mL/min. The analytical technique was successfully designed and validated. The AQbD technique was used to optimize the analytical conditions for the suggested methodology, and the Design Expert 13® trial version was used for the central composite design optimization of analytical conditions. The procedure's linearity was verified using a regression coefficient of 0.999 within a working range of 0.5 to 3 μg/ml. Accuracy research showed results of 99.94–100.10% at 50, 100, and 150% levels of the working concentration. The oxibendazole impurity's average retention time was found to be 6.40 minutes, with a relative standard deviation of less than 2%, indicating high accuracy. The limits of detection (LOD) and quantification (LOQ) were found to be 0.073 and 0.091 μg/ml, respectively. Following the ICH Q2(R1) criteria, other validation criteria, such as robustness, were also evaluated. In conclusion, the proposed approach is suitable for analysing albendazole and oxibendazole in bulk and pharmaceutical formulations, making it ideal for detecting oxibendazole impurities.