Module 3 2019

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% • Pre approval protocol should carry requirements for correlation coefficient and y intercept • Can handle intercept statistically – or empirically • Analysis of residuals can prove helpful

Question: Is linearity important?

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