Write a Note on Requirements for residual solvents in pharmaceutical products.
RESIDUAL SOLVENTS UNDER USP 467 (ICH Q3C) GUIDELINES
Residual solvents in pharmaceuticals are defined by the ICH as organic volatile chemicals that are used or produced in the manufacture of drug substances, excipients, or in the preparation of drug products. In general, solvents are not completely removed by practical manufacturing techniques. Solvents provide no therapeutic benefit, therefor all residual solvents should be removed to the extent possible to meet product specifications, good manufacturing practices, or other quality-based requirements. Appropriate selection of solvent for processing of a drug substance may enhance the yield, allow isolation of a preferred crystal form, improve purity, or enhance solubility. Therefore, the solvent can play a critical role in the synthetic process. Given the presence of solvents in most pharmaceutical processing steps, the content of solvents in pharmaceutical products should be evaluated.
Drug products should contain no higher levels of residual solvents than can be supported by safety data. Commonly used solvents have been grouped by toxicity under the ICH Q3C guidance.