Chemical stability of diclofenac sodium injection.

The stability of diclofenac sodium injection was studied by means of a stability-indicating high-performance liquid chromatography assay method that was developed in our laboratory. There was a direct relationship between the peak heights and the concentrations. The percent relative standard deviation based on five injections was 0.9. The products of decomposition and the excipients present in the dosage form did not interfere with the developed assay method. The injection was stable for at least 23 days when stored in clear glass vials at room temperature. Contrary to the recommendation in the literature, the injection may not be stored at the refrigerated temperature. The physcial appearacne and the pH value of the injection did not change during the study period.