Control of synthetic impurities

Maximum daily dose (g/day) Reporting threshold (%) Identification threshold s Qualification threshold s 

Higher reporting thresholds should be scientifically justified. 

Examination of the chromatograms shows that some impurities are unique to one particular manufacturer while others are common to more than one manufacturer although the relative amounts may vary widely. Note also that the total impurities values range from 0.10% to 1.00%. The very large peak at retention time of 21.1 min is fluoxetine. 

ICH Q3 A(R) [8] provides a clear guidance for the control of the organic impurities. Table 1.1 describes the hmits or thresholds for the reporting, identification, and qualification of the impurities based on the maximum daily dose of the drug substance administered per day. 

Attempts at structural identification of the compound are expected for impurities above the identification threshold. The evaluation of biological safety is expected above the qualification threshold. 

---