Chlortetracycline hydrochloride is a salt prepared from chlortetracycline taking advantage of the basic dimethylamino group which protonates and readily forms the salt in hydrochloric acid solutions. The hydrochloride is the preferred formulation for pharmaceutical applications. Like all tetracyclines, chlortetracycline shows broad spectrum antibacterial and antiprotozoan activity and acts by binding to the 30S and 50S ribosomal sub-units, blocking protein synthesis.