The synthesis of active pharmaceutical ingredients (API) may require multiple reaction steps that produce undesirable reaction byproducts or utilize various solvents that have to be removed from the finished product.
Method USP 467 classifies residual solvents into three classes according to toxicity; class 1 solvents are to be avoided unless there is strong justification, class 2 solvents are those that should be limited due to toxicity concerns, class 3 solvents are less toxic and ideally used were practical.
This application note explains:
- How to measure solvents and by products with headspace gas chromatography
- FID performance at the concentration limits for solvents