Quantitative analysis of, the principle soy isoflavones genistein, daidzein and glycitein, and their primary conjugated metabolites in human plasma and urine using reversed-phase high-performance liquid chromatography with ultraviolet detection

Soy isoflavones are becoming of increasing interest as nutritional agents w hich can be used to combat osteoporosis and hyperlipidemia, and are also be ing considered as potential cancer chemopreventive compounds. However, prio r to their formulation and distribution as therapeutic agents, thorough pha rmacokinetic and toxicological assessment needs to be completed in men and women in a variety of health conditions in order to ensure their therapeuti c efficacy and safety. At this time, studies of purified soy isoflavones ar e possible, and are being designed to fully evaluate the pharmacological ut ility of these preparations. In support of these studies, quantitative anal ysis of soy isoflavones in biological fluids can be accomplished with a wid e variety of methods and analytical instrumentation. However, the relativel y ubiquitous presence of high-performance liquid chromatography with ultrav iolet detection (HPLC-UV) in most analytical laboratories, the relative eas e of its operation, and the lesser expense of this instrumentation as compa red to more sophisticated techniques such as liquid chromatography-mass spe ctrometry, offers some distinct advantages for its use in pharmacokinetic s tudies. In this manuscript, the development and validation of an HPLC-UV me thod for the quantitation of the prinicipal soy isoflavones,,genistein, dai dzein, and glycitein, and their primary metabolites, in human plasma and ur ine is described. This analytical approach allows for pharmacologically rel evant concentrations of the analytes and their principle metabolites to be detected, and has been validated in close agreement with the US Food and Dr ug Administration's guidelines for the validation of methods to be used in support of pharmacokinetic studies. (C) 2001 Elsevier Science B.V. All righ ts reserved.