Stability Indicating LC Method for the Determination of Ketoprofen in Presence of its Impurity.

The analytical chemistry has to be a part of the progress of the researches on the contamination of the water by medicines; she has to establish processes of validated analyses, for the detection and the dosage of diverse pharmaceutical substances. On this matter the proposed analysis concerns the detection and the dosage of the ketoprofen within all products of damages. A high performance liquid chromatographic method for the determination of ketoprofen in the presence of one related impurity and its degradation products is described. The method is based on the use of an C18 phase column (SUPERCOSIL TM LC-18-DB) and a mobile phase of acetonitrilepotassium phosphate acid (0.05 M, pH 4.5) - water (43: 2: 55, v/v/v)with 0,3 millimoles of Octyl Sulfate of sodium (OSS),all at pH 4,5. All peaks are eluted in <15 min. The method was demonstrated to be precise, accurate and specific. Degradation study showed that the drug is stable in basic medium while it degrades under oxidative conditions and acidic medium. The results indicated that the proposed method could be used in a stability assay.