Development of a spectrophotometric method for the assay of Diclofenac potassium

Diclofenac potassium is a nonsteroidal anti-inflammatory drug and a prostaglandin (PG) synthetase inhibitor. The objective of this study was to develop a spectrophotometric method for the assay of diclofenac potassium. A series of diclofenac potassium solutions were prepared ranging from 200 ppm to 12.5 ppm. After preparation of a standard stock solution of 200 ppm in 100 ml of water, different dilutions were made (100ppm, 50ppm, 25ppm and 12.5ppm). At the wavelength 242nm, the absorbance of the standard preparation and dilutions was measured using a UV spectrophotometer. In this study a precise and accurate method was developed. The validation of the developed method for the assay of diclofenac potassium was done by various parameters that included linearity, accuracy test and precision. The method showed good reproducibility and good recovery with % RSD less than 2. The method was found to be simple, economical, rapid, specific, precise and accurate.