Solvents, not grouped in Class-1, Class-2 and Class-3, are often required to attain desirable properties of drug substances, products and excipients. Their use is particularly important in drug substances where a specific polymorph determines the bioavailability of drug product. How the limit of of such solvents is determined in pharmaceuticals, is the topic and content of this video. Further what other strategies are made available to regulatory personnel to justify such solvents' limits in pharmaceuticals.

https://www.youtube.com/watch?v=ura6XdNSI7Q&t=9s