improved chromatographic method for determination of sodium diclofenac in injectable solution and prediction of chemical stability

two modified methods for assaying sodium diclofenac were developed by gc and hplc. diclofenac was converted into methyl ester derivative by methyl iodide in acetone. the ester was extract and subjected to glc with flame ionization detector. %5 se-30/chrom w-hp (80-100 mesh) was used as a column in gc. for reversed phase hplc, the mobile phase was methanol and water (55-45). the separation was performed on an analytical 300×3.9 mm i.d. ?-bondapak phenyl column using uv detector (274 nm). o-(4-chlorobenzoyl)benzoic acid and mefenamic acid were used as internal standard for gc and hplc method respectively. the stability of diclofenac was examined by results obtained from two chromatographic methods at high temperature. the described hplc and gc methods were successfully applied for the prediction of the shelf life period of diclofenac.