The administering or dispensing directly, but not prescribing, of any controlled substance listed in any schedule to a drug dependent person for the purpose of continuing his or her dependence upon the drugs in the course of conducting an authorized clinical investigation in the development of a treatment and rehabilitation program for drug dependent persons shall be deemed to be within the meaning of the term "in the course of professional practice," provided that:
R.I. Gen. Laws § 21-28-3.21