Human radiolabeled mass balance studies: objectives, utilities and limitations

摘要: The determination of metabolic pathways a drug candidate through the identification circulating and excreted metabolites is vitally important to understanding its physical biological effects. Knowledge metabolite profiles in animals humans essential ensure that animal species used toxicological evaluations new candidates are appropriate models humans. recent FDA final guidance recommends human oxidative whose exposure exceeds 10% parent AUC at steady-state should be assessed least one preclinical assessment. Additional testing on have higher than may required. laboratory generally accomplished by mass balance excretion studies which radiolabeled drugs administered these species. fluids collected, analysed for total radioactivity evaluated quantitative profile metabolites. Thus, not only determine rates routes but also provide very critical information In addition, required regulatory agencies approval process. Despite usefulness studies, there little concrete how perform or assess complex studies. This article examines objectives, utilities limitations could