New and Sensitive Spectrofluorimetric Method for the Determination of Non-Steroidal Anti inflammatory Drugs, Etodolac and Diclofenac Sodium in Pharmaceutical Preparations through Derivatization with 7-fluoro-4-nitrobenzo-2-oxa-1,3-diazole

Abstract

A rapid, accurate and sensitive method was developed and validated for the determination of non-steroidal anti-inflammatory drugs, etodolac and diclofenac sodium in pharmaceutical preparations. The proposed method was based on the reaction of these drugs with 7-fluoro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-F) in buffer of pH 8.5 to yield a yellow, fluorescent product. The method was validated for specificity, linearity, limit of detection, limit of quantification, precision, accuracy, recovery and robustness. Beer's law is obeyed over the concentration range of 40 - 600 ng/mL for etodolac, 25 - 500 ng/mL for diclofenac sodium, respectively. The detection limits were found to be 0.071 ng/mL for etodolac, 0.055 ng/mL for diclofenac sodium, respectively. Statistical analysis of the results has been carried out revealing high accuracy and good precision. The proposed methods were successfully applied for the determination of the drugs in their pharmaceutical preparations with good recoveries. The developed methods were sensitive, accurate and simple. The results obtained by the proposed method were comparable with those obtained by the official method.