if we changed excepient in formula, then its need to do validation ???
There are FDA guides which address the issue of changing excipient quantity
As i know for change in Vendor supplier ( change in manufacturer) we do the Process validation , if we change the one of excepient of formula , then must be validation done for that product .
pls comment on my point .
See the FDA SUPAC Guidance documents, they include the answers
Yes change of excipients is also validated