Can a generic manufacturer use a different ingredient/excipient while still submitting drug as a generic?

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The generic needs to have the same API (Active Pharmaceutical Ingredient) composition (qualitative and quantitative) as the one of the brand leader.
There is no obligation to have the same composition in excipients, even though some generic companies prefer to stick to the same excipients as long as they have the same dosage form.
ex.: immediate release film-coated tablet,  there is no problem to use Lycoat or ReadiLycoat instead of HPMC or PVA  based coating system as long as it has the same functionality.

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Does Roquette as a manufacturer has to perform identification tests?

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