Module 3 Presentations

07/05/2024

Drug Substance Assay Selectivity

• “Ability to assess unequivocally the analyte in the presence of components which may be expected to be present” • Dependant on method application • May require a combination of two or more methods • Retention time recording of structurally related impurities, degradation products etcrecorded during method development • Peak purity assessment can be carried out during stress testing studies using either (simply) LC DAD and/or LC-MS or multiple methods

The Organisation for Professionals in Regulatory Affairs

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Drug Substance Assay Linearity

• “The linearity of the analytical method is its ability (within a given range) to obtain test results which are directly proportional to the concentration (amount) of analyte in the sample” • For a drug substance assay • ICH recommends 5 concentrations minimum over the range 80-120%

Question: Is linearity important?

The Organisation for Professionals in Regulatory Affairs

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