The board and its duly authorized agents and employees may inspect controlled premises and practitioners’ offices during business hours and in a lawful manner upon presenting appropriate credentials for the purpose of examining: (a) Any books, inventories, records or other documents required to be kept by a registrant under the provisions of this act or regulations issued pursuant thereto;

(b) all pertinent equipment, finished and unfinished material, containers and labeling found therein and, all other things therein, including but not limited to processes, controls and facilities; and

(c) inventory any stock of any controlled substance therein and obtain samples thereof upon payment therefor.