The provisions of sections 18-18-419 to 18-18-424 shall not apply to practitioners licensed, registered, or otherwise authorized under the laws of this state to possess, administer, dispense, or distribute a controlled substance, if the distribution, possession, dispensing, or administering of the imitation controlled substance is done in the lawful course of his professional practice.
C.R.S. § 18-18-424
For the "Colorado Licensing of Controlled Substances Act", see part 2 of article 80 of title 27.