Rubi,
per ISO 10993-1:2018 (or 2009), you have to evaluate the biocompatibility of the _final_ device according to its intended use as it comes into patient contact. Testing, including a cytotoxicity test, is only warranted if your existing data does not allow you address all trelevant biologiocal endpoint via material characterization - refer to Table A.1.
Cytotoxicity testing of raw material alone is typically not sufficient to establish biocompatibility of your medical device.
What kind of equivalence do you want to show?
HTH,
Gerhard