Reversed-phase high-performance liquid chromatography of ketorolac and its application to bioequivalence studies in human serum.

A reversed-phase high-performance liquid chromatographic assay was used to study the bioequivalence of the anti-inflammatory drug (+/-)-ketorolac in human volunteers. Following deproteinization of human serum with 5% zinc sulphate solution, ketorolac was chromatographed on a 10-microns octadecylsilica column using acetonitrile-water as mobile phase and ultraviolet detection at 313 nm. Under these conditions the method was reproducible with a coefficient of variation of less than 5%. The assay procedure was linear in the range 0.25-1.5 micrograms/ml, with a sensitivity of 0.01 micrograms/ml ketorolac. The recovery of ketorolac from serum ranged from 90 to 95%.