Validation of an analytical procedure--control of residual solvents in pharmaceutical substance.

In this study elements of validation of headspace GC method of determination of residual methanol, n-pentane, ethanol, tert-butylamine, 2propanol, acetonitrile, dichloromethane and toluene in pharmaceutical substance are presented. Validation of the method included: selectivity, system precision, method precision, accuracy (recovery), limits of detection and quantitation (in substance), robustness and linearity. Acceptable levels of these solvents are included in guideline Q3C issued by ICH (1) and must not exceed: methanol 3000 ppm, n-pentane, ethanol, 2propanol 5000 ppm, acetonitrile 410 ppm, dichloromethane 600 ppm, and toluene 890 ppm. Specification limit has been established for tertbutylamine at the level of 1000 ppm.