Thimerosal Analysis in Ketorolac Tromethamine Ophthalmic Solution. Comparing Hplc and Colorimetric Techniques

Abstract

AbstractKetorolac tromethamine, a pyrrolopyrrole, is a nonsteroidal anti-inflammatory drug under development as a topical agent for treating ocular disorders associated with inflammation. Thimerosal is a commonly-used antimicrobial preservative in ophthalmic solutions. This report describes both stability-specific (HPLC) and non-specific (colorimetric) methodology for determining thimerosal stability in ketorolac ophthalmic solution.The HPLC technique used a reverse-phase Whatman RAC II (C8) column (5 micron particle size. 10 cm × 4.6 mm 1.0.) with a 30:67:3 by volume mixture of methanol:10mM acetate buffer (pH 4.5) and tetrahydrofuran as the mobile phase. Detection was at 254 nm.Thimerosal peak purity, in thermally stressed ketorolac ophthalmic solution 1s confirmed using absorbance ratio techniques. Accuracy and linearity data are presented.In addition, a colorimetric (dithizone) technique for quantifying total organic mercury in solution is described. Both the HPLC and colorimetric techniques were used...