## Facts

- PREVOR, a French company, developed Diphoterine™ Skin Wash (DSW) for workplace use to reduce injuries from accidental chemical exposure.
- DSW was marketed outside the United States as a medical device and registered or licensed as a device in multiple jurisdictions.
- DSW is a pressurized canister that sprays a mostly water-based liquid (about 96% water and 4% diphoterine) onto skin.
- DSW’s intended uses were to (1) wash acids and bases off skin by physical/mechanical removal and (2) neutralize and dilute acids and bases.
- PREVOR asserted DSW’s primary effect was mechanical (about 90%), with a secondary chemical effect (about 10%).
- FDA determined DSW was a drug–device combination product with a drug primary mode of action (PMOA), requiring regulation through the drug pathway (including an NDA) rather than the device pathway.
- PREVOR challenged the designation as inconsistent with the FDCA’s drug/device definitions and inadequately explained under the Administrative Procedure Act (APA).

## Issues

1. Whether FDA acted arbitrarily and capriciously under the APA by designating DSW as a combination product with a drug PMOA.
2. Whether FDA reasonably applied the FDCA’s “drug” and “device” definitions and the PMOA framework to DSW based on the administrative record.

## Decision

- The court granted PREVOR’s motion for summary judgment and denied FDA’s cross-motion.
- The court held FDA acted arbitrarily and capriciously in designating DSW as a drug–device combination product with a drug PMOA.
- The court set aside the designation and remanded the matter to FDA for further consideration consistent with the court’s reasoning.

## Legal Principles

- Under the APA, agency action must be set aside if it is arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law.
- An agency must provide a reasoned explanation showing a rational connection between the facts found and the choice made, and must address important aspects of the problem.
- The FDCA distinguishes “devices” from “drugs” in part by whether the product achieves its primary intended purposes through chemical action within or on the body and/or is dependent on metabolism.
- For combination products, FDA must identify and explain the product’s PMOA and apply a coherent, consistently stated standard for determining which mode of action is primary.

## Conclusion

The court vacated FDA’s drug-PMOA designation for DSW because FDA did not adequately explain why chemical effects were “primary” over mechanical washing, did not apply a clear and consistent PMOA standard, and did not connect the record evidence to its classification decision; the matter was remanded to FDA for reconsideration.


Prevor v. Food & Drug Admin., 895 F. Supp. 2d 90 (D.D.C. 2012)