It is an affirmative defense to prosecution or liability under this chapter that:
(1) the abusable synthetic substance was approved for use, sale, or distribution by the United States Food and Drug Administration or other state or federal regulatory agency with authority to approve the substance's use, sale, or distribution; and
(2) the abusable synthetic substance was lawfully produced, distributed, sold, or offered for sale by the person who is the subject of the criminal or civil action.