; and (B) such article is designated in such system as a drug, device, dietary supplement, or other product that is regulated under this Act. (2) Articles covered Subject to paragraph (1), for purposes of this section, an article described in this paragraph may be treated by the Secretary as a drug if it— (A) is or contains an ingredient that is an active ingredient that is contained within— (i) a drug that has been approved under section 505 of this Act; or (ii) a biological product that has been approved under section 351 of the Public Health Service Act; (B) is or contains an ingredient that is an active ingredient in a drug or biological product if— (i) an investigational use exemption has been authorized for such drug or biological product under section 505(i) of this Act or section 351(a) of the Public Health Service Act; (ii) substantial clinical investigation has been instituted for such drug or biological product; and (iii) the existence of such clinical investigation has been made public