SIMPLIFIED LIQUID-CHROMATOGRAPHY ASSAY FOR THE QUANTITATION OF HALOFANTRINE AND DESBUTYLHALOFANTRINE IN PLASMA AND IDENTIFICATION OF A DEGRADATION PRODUCT OF DESBUTYLHALOFANTRINE FORMED UNDER ALKALINE CONDITIONS

The development of a new and simplified, validated LC assay for the qu antitation of halofantrine and desbutylhalofantrine in plasma is descr ibed. The methodology employs an inexpensive, rapid and simple liquid- liquid extraction procedure in combination with previously reported ch romatographic conditions. The method has been employed to study aspect s of the pharmacokinetics of orally administered halofantrine in beagl e dogs and some preliminary data are presented. During development of the extraction procedure, degradation of desbutylhalofantrine was obse rved under non-acidic conditions in the extraction solvent (tert-butyl methyl ether) and we also report the structural elucidation of the br eakdown product and the conditions required to avoid this degradation.