stability indicating method

[gtma]

Could anyone tell me for a pre-clinical stage drug, if you need to seperate significant related substances from each other. What is your practise or objective in developing related substances method for pre-clinical stage?

Thanks

[DR]

I would suggest that you need to start forced degradation studies and development of a decent SI method now if there's a good chance that you will ever be going to clinical trials. While SI methods used to support stability during clinicals need not necessarily be fully validated, you should at least have some confidence in them (they should be "validatable" - they should resolve known process impurities from degradation products, and they should have passed some peak purity testing, and major deg. products and impurities should be ID'd).