Mass Balance, Excretion and Expired Air Collection

Mass balance is the term that used to balance the amount of drug administered with the amount of drug-related substances collected in human excreta (usually feces and urine, as well as expired air). Mass balance assays are also known as "C-14 studies" or "absorption, metabolism and excretion (AME) studies". And mass balance studies are often an important part of regulatory submissions.

The main objectives are usually:

  • Determine the mass balance of drug-related substances after administration
  • Calculate the percentage of metabolites in the circulation between drugs and blood
  • Identify the main excretory routesa of drug-related substances
  • Analyze whether compounds need to be evaluated for potential drug-drug interactions

Mass Balance, Excretion and Expired Air Collection

Creative Bioarray provides services for studying mass balance using radio-labeled compounds. We perform mass balance studies in mice, rats and dogs. In general, radio- labeled compounds are administered intravenously or orally, and excretion is monitored in urine, feces. The results of this assay can be used to characterize drug excretory routes, clearance rates and pharmacokinetics of drug-related substances.

Our services include:

  • Total radioactivity of all substrates (measured by liquid scintillation count and accelerator mass spectrometry)
  • Biological analysis (LC-MS/MS)
  • Metabolite spectrum
  • Metabolite identification

Our team has impeccable quality and reputable data, and we can support comprehensive research from the beginning of the study design and protocol to the release of the final clinical study report. If you have any special needs or questions regarding our services, please feel free to contact us to get support from our experienced experts. We look forward to working with you in the future.

For research use only. Not for any other purpose.