KINETIC SPECTROPHOTOMETRIC DETERMINATION OF TAPENTADOL
A simple, inexpensive, accurate and sensitive spectrophotometric method and kinetic assay have been established to determine tapentadol in pure form, tablets and urine samples. The method is based on the reaction of tapentadol with ferric ions in an acidic solution in the presence of ferricyanide to give water-soluble Prussian blue dye with a maximum absorption wavelength of 735 nm, with a maximum reaction time of 40 minutes. Several experimental factors affect the colour intensity and stability time approaches. The reaction was identified as a first-order pseudo-reaction by calculating the initial rate, and the results of the fixed- time method (at 30 min) are more suitable for quantification and used to construct the calibration curves. The correlation between concentration and absorbance was linear. Moreover, varies from 2 to 12 μg/mL and has a detection limit of 0.1737 μg/mL and a quantification limit of 0.5264 μg/mL. The molar absorption coefficient and Sandel sensitivity were 1.5484 x 10 4 L.mol-1.cm-1 and 0.01430 μg.cm-2, respectively. A comparison of spectrophotometric data with a well-established fixed time kinetic demonstrated that the fixed time technique offers good accuracy, precision, low detection and quantification limitations, and is time efficient. These procedures were effectively used to analyze tapentadol in its pure form, tablet form, and urine sample, which were not observed in literature before
Keywords: Kinetic Spectrophotometric; Tapentadol: Ferric Chloride,Potassium- Ferricyanide.