12. Prohibition or regulation of the disposal of drugs. If in the opinion of the Chief Commissioner it is necessary or expedient so to do, he may, by order in writing--
prohibit the disposal of any drug except in such circumstances and under such conditions as may be specified in the order;
direct the sale of any drug to any such dealer or class of dealers and in such quantities as may be specified in the order; and make such further orders as appear to him to be necessary or expedient in connection with any order issued under this section.