ABSTRACT
The guideline recommends the use of less toxic solvents and describes levels considered to be toxicologically acceptable for some residual solvents. Residual solvents in drug substances, excipients, and drug products are within the scope of this guideline. The new term permitted daily exposure is defined in the present guideline as a pharmaceutically acceptable intake of residual solvents to avoid confusion due to differing values for acceptable daily intake's of the same substance. Residual solvents are typically determined using chromatographic techniques such as gas chromatography. Any harmonized procedures for determining levels of residual solvents as described in the pharmacopoeias should be used if feasible. Residual solvents are unavoidable components in pharmaceutical production and will often be a part of drug products. Manufacturers of pharmaceutical products need certain information about the content of residual solvents in excipients or drug substances in order to meet the criteria of this guideline.
