Screening for residual solvents

Solvents can be used during the synthesis of active ingredients and during the production of medicinal products, and these may not be removable completely from the end-product. Some of these solvents can be highly detrimental to health, which is why their use is entirely forbidden in the European Union (EU). For others, strict threshold values are in place.

The European Pharmacopoeia (Ph. Eur.) limits the amount of residual solvents in active ingredients, excipients and finished products (Ph. Eur. 5.4). The solvents are grouped into Classes 1 – 3, depending on their potential danger to health and their environmental compatibility. Class 1 contains solvents with a carcinogenic risk or a risk for the environment. Class 2 contains solvents with non-genotoxic carcinogenic toxicity and other solvents with irreversible (neurotoxic, teratogenic) and significant reversible toxicity. Solvents with low toxic potential fall into Class 3.

Tests offered

The method used by InphA is suitable for screening active ingredients and excipients for the presence of residues of the following solvents:

  • Class 1: Benzene, 1,1-dichlorethylene, 1,2 dichlorethane, carbon tetrachloride, 1,1,1-trichlorethane,
  • Class 2: Acetonitrile, chlorobenzene, chloroform, cyclohexane,  cis 1,2-dichlorethene, trans 1,2-dichlorethene, dichlormethane, 1,2-dimethoxyethane, 1,4-dioxane, n-hexane, methanol, methylbutylketone (2-hexanone), methylcyclohexane, nitromethane, pyridine, tetrahydrofuran, tetralin, toluene, 1,1,2-trichlorethene, xylene.

Testing material

Active ingredients and excipients.