California Code, Business and Professions Code - BPC § 4163

(a) A manufacturer, wholesaler, repackager, or pharmacy shall not furnish a dangerous drug or dangerous device to an unauthorized person.

(b) Except as provided in subdivision (c), dangerous drugs or dangerous devices shall be acquired from a person authorized by law to possess or furnish dangerous drugs or dangerous devices.  If the person acquiring the dangerous drugs or dangerous devices is a wholesaler, the obligation of the wholesaler shall be limited to obtaining confirmation of licensure of those sources from whom it has not previously acquired dangerous drugs or dangerous devices.

(c) Upon approval of the board, a reverse distributor licensed as a wholesaler may acquire a dangerous drug or dangerous device from an unlicensed source that was previously licensed with the board for the sole purpose of destruction of the dangerous drug or dangerous device.