Validation of an uv-visible method for the assay of diclofenac sodium: Its use in decontamination rate of this active ingredient by natural adsorbents [Validation d'une méthode de dosage du diclofénac sodique par uv-visible: Application à la décontamination de ce principe actif par des adsorbants naturels]

A simple,accurate and precise uv-visible method for the determination of diclofenac was developed,optimized and validated. also,the method was used for the quantification of the active ingredient in pharmaceutical formulations and especially to monitor the ability of some natural adsorbents to decontaminate solutions loaded with diclofenac sodium. the proposed method is based on a reaction with the sodium diclofenac and nitric acid 14 m,resulting in a yellow colored compound which was extracted with ethyl acetate. the maximum absorbance was measured at 353 nm. beer's law is fulfilled within a concentration range of 5 to 30 μg/ml of diclofenac sodium with a correlation coefficient r = 0.9982. the limits of detection and quantification are 1.012 μg/ml and 3.067 μg/ml respectively. the method was validated in compliance with ich requirements q2r1 and those of the french society of pharmaceutical science and technology 1992 (sfstp). validation criteria (linearity,accuracy,precision and limit of quantification and detection) were used to judge the reliability of the method and therefore,it was used to evaluate the rate decontamination using natural adsorbents. the montmorillonite absorbent can be considered as the best one according to its excellent rate decontamination recovery (84% in 5 min). while the activated shale,the activated carbon and the kaolinite gave the following rate 80.3%,29.3% and 14% in the same time (5 min) respectively. natural adsorbents tested can be used for the decontamination of solutions loaded with active ingredient as the diclofenc sodium.