A radiolabelled study may not represent the “real-world” use of the drug. Therefore, the ensuing total residue depletion data may not accurately predict real-world residue concentrations. To determine likely “real-world” drug residues, it is necessary to conduct a separate marker residue depletion study.  

Consult the guidance document on marker residue depletion studies to:

• understand why a marker residue depletion study is required in addition to a total residue study;
• learn about the characteristics of a well-performed marker residue depletion study;
• find relevant guidance documents regarding marker residue depletion study design and analytical methodology; and
• access a hypothetical data set to begin practicing drug residue depletion data analysis.