The members of the Board, its inspectors and investigators are designated and constituted agents for the enforcement and carrying out of the provisions of this chapter, and for this purpose they are entitled to have free access at all times during business hours to all places where drugs, medicines or poisons or devices or appliances that are restricted by federal law to sale by or on the order of a physician are held or offered for sale and to all records of sale and disposition of drugs, medicines or poisons or devices or appliances that are restricted by federal law to sale by or on the order of a physician.