Lawyers representing outsourcing compounders are signaling they may sue FDA should it finalize guidance outlining its plans to evaluate whether there is a clinical need to compound a drug using bulk active pharmaceutical ingredients. The compounders throw a number of legal arguments at FDA, including that the guidance is effectively a rule and must go through notice-and-comment rulemaking, that making such determinations would allow FDA to practice medicine, and that treating 503A and 503B compounders differently is arbitrary and capricious...