I’m not sure that’s the case, but in any event the DOJ could absolutely charge an individual with violating 28 USC 331 (which is the FDCA’s forbidden acts provision) and seek a prison term or fine against that individual under 28 USC 333. That latter section pretty clearly contemplates individual violation of the laws because corporations can’t be imprisoned.
Regardless of who enforces the law, the point is that the individual and the corporation aren’t really facing distinguishable labeling requirements such that you could say the individual enjoyed more First Amendment protection than the corporation for misbranding drugs.
