Impurity Specification Limit Calculation

Thresholds Specification Limit for Drug Substance in % Specification Limit for Drug Product in %
Reporting Threshold - -
Note: LOQ (Limit of Quantification) should ideally be lower than or equal to the reporting threshold.
Identification Threshold - -
Note: Unknown impurities must be below or equal to the identification threshold.
Qualification Threshold - -
Note: Qualification Threshold is typically the limit for known impurities; above this, safety qualification is required.
Calculation Details
ICH Q3 Guidelines Reference
Daily Dose ≤ 2g: Reporting: 0.05%, Identification: 0.10%, Qualification: 0.15%
Daily Dose > 2g: Reporting: 0.03%, Identification: 0.05%, Qualification: 0.10%
Genotoxic Impurities: Follow ICH M7 guidelines (ppm levels)
Residual Solvents: Follow ICH Q3C guidelines