The partial filling of a prescription for a controlled substance listed in Schedules III, IV or V is permissible within six (6) months after date thereof provided that the following occurs:
The remaining portion of a partially filled prescription may be filled within seventy-two (72) hours of the first partial filling; however, if the remaining portion is not or cannot be filled within the seventy-two (72) hour period, the pharmacist shall so notify the prescribing individual practitioner. No further quantity may be supplied beyond seventy-two (72) hours without a new prescription.
D.C. Mun. Regs. tit. 22, r. 22-B1311