Section 21B. (a) For the purposes of this section, the following words shall have the following meanings unless the context clearly requires otherwise:

''Lock box'', a box with a locking mechanism that cannot be tampered with or opened without extreme force.

''Pharmacy'', a facility under the direction or supervision of a registered pharmacist which is authorized to dispense controlled substances; provided, however, that ''pharmacy'' shall not include an institutional pharmacy or a pharmacy department except as otherwise provided in 247 CMR.

''Prescription drug'', a drug which, under federal law, is required, prior to being dispensed or delivered, to be labeled with the statement ''Caution, federal law prohibits dispensing without prescription'' or a drug which is required by applicable federal or state law or regulation to be dispensed pursuant only to a prescription drug order.

(b) A pharmacy registered in the commonwealth to dispense schedule II, III, IV or V prescription drugs shall make available prescription lock boxes for sale at each store location. Pharmacies shall make customers aware of the availability of the lock boxes by displaying a sign on or near the pharmacy counter that: (i) is at least 4 inches by 5 inches; and (ii) includes the following statement in legibly printed font: ''Lock boxes for securing your prescription medications are available at this pharmacy''.