Mass balance excretion studies

Mass Balance studies in laboratory animals using radiolabeled novel compounds represents a standard part of the development process for new drugs. From this type of study the total fate of drug-related material is obtained: mass balance, routes of excretion, and with additional analyses, metabolic pathways.

  • Investigate the plasma pharmacokinetics (PK) and excretion of both the unchanged novel compound and the total radioactivity (drug and metabolites)
  • Allows elucidation of the metabolic fate of a novel drug
  • Provide fundamental information about the rates and routes of elimination of a novel compound

This is a vital component of regulatory submissions. The main objective of a Mass Balance study is the maximum recovery of the radioactive dose in urine and feces. The radiolabeled novel compound must be prepared, characterized, administered and the biological samples must be collected and analyzed properly to obtain reliable and meaningful results.

We perform various mass balance studies in multiple species (rodents and non-rodents) with numerous isotopes including 14C, 3H, and 125I (others can be used). Your novel compound can be administered via intravenous or oral, and excretion of radioactivity is monitored in urine, feces, and occasionally bile and CO2. If required samples of blood, urine, feces as well as tissues can be collected both pre- and post-dose to meet your specific needs. We offer standard or customized mass balance services to meet your programs requirements.