Second Derivative Spectrophotometric Determination of the Degradation Products of Diclofenac Sodium in Gel-Ointment

Abstract

A second derivative spectrophotometric method has been developed for the determination of the degradation products from diclofenac sodium in gel-ointment. The amplitudes in the second derivative spectra at 260 and 265 nm were selected to determine oxindol. A linear relationship between derivative amplitudes and a concentration of compounds was found. The detection limit of oxindol was estimated to be 0.01% with respect to the gel-ointment. The method is rapid, simple, specific and does not require any preliminary separation or treatment of the samples. The proposed method is statistically validated and found to be accurate, sensitive and reproducible.

Key Words:

• Derivative
• Spectrophotometry
• Diclofenac Sodium
• determination of degradation products
• Oxindol