Validation for change in Supplier

Can you advise please on the level of validation that is required for a change in excipient for tablet manufacturing?

I don’t think anyone would be able to give you sound direction based on just what you provided. The approach you should take is to assess the change for risk and perform a commensurate level of validation. Document your decision and rationale.

Refer Variation guidance of Europe and SUPAC Guidance of US.