Another combination product on the market is a catheter with antimicrobial coating. They are used to lower the risk of catheter colonization and infection. The Foley catheter, for example is describe as “flexible tubular device that is inserted through the urethra and used to pass fluids to or from the urinary tract.” These type of devices are classified as Class II and I think they should be regulated under CDRH. Changes to the device should be made in line with 21 CFR 807.87 and significant changes may require 510k submission. The FDA also may require additional information such as a rationale for the modification, any bench, animal, clinical, functional, in vitro, and/or any other testing data to support marketing claims. Significant changes to the antimicrobial agent that is used on the catheter is the subject of an approved new drug application NDA as per CDER guidance.

https://www.fda.gov/MedicalDevices/ucm080884.htm