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Please note that we are not a pharmacy or clinic, so we are unable to see patients and do not offer diagnostic and treatment services for individuals.


Mass Balance Studies

Mass balance studies are performed to determine the excretion rates and pathways of the parent compound and its metabolites. Our company employs talented and highly trained scientists focused on all aspects of rare disease drug development and research. We have the capabilities and resources to provide professional communication and problem-solving support to accelerate mass balance studies.

Introduction to Mass Balance Studies

The purpose of mass balance studies is to reveal the amount of a compound absorbed into the systemic circulation, focusing more on how a drug candidate is processed in the body to be eliminated from the body.  

Mass balance studies are typically used to measure the excretion of radiolabeled compounds in urine, feces, bile, and exhaled breathed. Species for preclinical radioactive mass balance studies should be selected based on the results of metabolite studies and species for toxicology studies. This radioactive study is generally performed on a small number of individuals at an early stage. If active or reactive metabolites are found, the study can be postponed as appropriate.

1-3-3-2-5 Mass Balance Studies-1 Fig.1 Typical strategies for compound mass balance studies. (Miyatake, D., et al., 2018)

Applications of Mass Balance Studies

Mass balance studies are an important component of regulatory submissions. Mass balance studies can be used to compare the dose and recovery from radioactive administration, to understand the absorption and metabolism of drugs, and to provide suggestions on the rationality of animal types for toxicological testing, which are of certain help to the pharmacological or toxicological effects of drugs and the development of subsequent clinical trials.

Our Services

  • Mass Balance Studies in Animal Models
    Providing a variety of isotopes including 3H or 14C to perform mass balance studies in a variety of animal species including rats, mice, dogs, monkeys, rabbits, minipigs, and guinea pigs.
    Providing reasonable routes of administration, usually through intravenous and/or oral administration, and set different time points for sample collection according to customer requirements.
  • Radioactive Analysis of Matrices

Standard Matrices

Employing talented and highly trained scientists, our company provides efficient methods to support radioactive analysis of standard matrices such as blood, plasma, urine, feces, etc.

Alternative Matrices

Our company provides radioactive analysis of bile, expired air, PBMCs, dialysate, CSF, vomitus, tissue biopsies and other matrices to provide a complete picture of compound excretion pathways and rates.

Project Workflow

1-3-3-2-5 Mass Balance Studies-3

Why Choose Us?

Our company has focused on all aspects of rare disease research for many years, particularly in mass balance studies. We have the capabilities and resources to provide professional communication and problem-solving support to ensure that we can quickly respond to the changing needs of your research projects. If you are interested in our services, please feel free to contact us for more information.


  • Miyatake, D., et al., "A phase I, open-label, single-dose micro tracer mass balance study of 14C-labeled ASP7991 in healthy Japanese male subjects using accelerator mass spectrometry." Drug Metabolism and Pharmacokinetics 33.2 (2018): 118-124.

All of our services and products are intended for preclinical research use only and cannot be used to diagnose, treat or manage patients.

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