Novel Green RP-HPLC Method for Simultaneous Determination of Sodium Diclofenac and Benzyl Alcohol as Bulk Mixtures and in Pharmaceutical Injectable Forms

Background: Determination of active substances in dosage forms besides the inactive ingredients, including preservatives is required as a complete analytical procedure. Therefore, a new practical, accurate, and green RP-HPLC method was developed to determine Sodium Diclofenac and Benzyl Alcohol simultaneously in bulk and pharmaceutical injectable forms. Material and Methods: The method is based on using of Ethanol: Sodium acetate 0.1%, pH =7(50: 50) v/v as mobile phase, and C8 5μ(4.6*150mm) Inert Sustain GL Sciences column at room temperature 〖25〗^° C, the flow rate was 1mL/min, the UV detector was set at 254 nm and the injection volume was 10 μL. Moreover, the greenness of the method was evaluated using the AGREE tool. Results and Discussion: The validity of the developed method is achieved according to ICH guidelines, it revealed good linearity over the concentration range of 20-100 ppm for Sodium Diclofenac and 50-150 ppm for Benzyl Alcohol with the correlation coefficients were obtained〖 R〗^2=0.9998,0.9999 respectively. The LOD and LOQ were 1.65 and 5.00 ppm for Sodium Diclofenac and 1.21 and 3.66 ppm for Benzyl Alcohol. The Precision was studied as intra- and inter-day with relative standard deviations not more than 2%, and the accuracy by mean recoveries ranged between 100.06 – 101.10% for Sodium Diclofenac and 100.10 -101.83% for Benzyl Alcohol. The developed method was successfully applied to determine both compounds in marketed injectable forms. Finally, the AGREE tool revealed a high degree of greenness for the developed method. Conclusion: The results showed that the developed method is green and suitable for the precise, accurate and rapid determination of Sodium Diclofenac and Benzyl Alcohol in bulk drugs and ampoules. Keywords: RP- HPLC, Sodium Diclofenac, Benzyl Alcohol, Injectable Forms, Method Validation, Greenness Assessment.