restricted limits

Solvents are widely used during the manufacturing, purification and processing of pharmaceutical substances. The residues of these solvents must be removed to the extent possible, as they do not have any therapeutic effect but can cause undesirable effects in the consumers. These solvent residues concentration should not exceed the limits prescribed in the ICH guidelines.  This present review work is emphasized on various techniques (Loss on drying, karl fischer titration, Thermogravimetric analysis, Near- IR spectroscopy, Thermal desorption GC-MS, Gas chromatography, Nuclear magnetic resonance spectroscopy) that are being used to remove the residual solvents with their merits and demerits.