A Multi-Component Solvent System for the Analysis of a Candidate Antimalarial by Normal Phase HPLC

Abstract

The new candidate antimalarial WR 180,409·H₃PO₄ (DL-threo-α-(2-piperidyl)-2-trifluoromethyl-6-(4-trifluoromethylphenyl)-4-pyridinemethanol phosphate) and its internal standard, WR 184,806·H₃PO₄ (DL-2,8-bis(trifluoromethyl)-4-1-hydroxy-3-(N-t-butylamino)propyl]-quinoline phosphate) are both hydrophobic, highly lipid soluble compounds. Organic extracts of biological fluids of these compounds can be separated and analyzed by normal phase systems. These organic extracts can be chromatographed by means of a Waters μ Bondapak CN column utilizing an organic solvent system composed of two major components (ethylene dichloride and hexane), one minor component (acetonitrile) and two trace modifiers (formic acid and water). Alterations in the proportions of the major components induce predictable shifts in the retention of the antimalarial and its internal standard, while alterations in the proportions of the minor component with respect to these major components induce predictable changes in column selectivity. If the trace modifiers are stabilized in proportionate amounts, proper concentrations of the major components will isolate the antimalarial and internal standard fraction from significant interference while simultaneous alteration of the amount of minor component will effect separation of the antimalarial from the internal standards.