drugn product degradent

[D WARD <davidward99@btinternet.com> (by way of John Dolman<info@the-dolman-consultancy.com>)]

Dear Jayakumar,
 
There are two types of impurities commonly found in
APIs
 
Impurities from the manufacturing process: Raw materials,
by-products, intermediates and solvents. these are dependant on the
manufacturing process used.
 
The other type of impurities are degradants: resulting from
the chemical breakdown of the API itself. Degradants are not dependant on
the manufacturing process, but may depend on the polymorphic state of the
API in some cases, which itself could be a function of the manufacturing
process. 
The mechanism of degradation may also depend on storage conditions
(temperature and moisture).
But generally for a given API you should see a fixed set of degradation
products.
 
Regards
David