(6) 'Drug' means (i) a substance recognized as a drug in the Official United States Pharmacopoeia/National Formulary; (ii) a substance intended for use in the diagnosis, cure, mitigation, treatment, or prevention of any illness, condition, or disease in humans or animals; (iii) a substance, other than food, intended to affect the structure or any function of the body of a human or an animal; or (i