Tetracycline hydrochloride is a derivative of tetracycline, a broad-spectrum antibiotic belonging to the tetracycline class. Chemically, it is tetracycline compounded with hydrochloric acid to enhance solubility. Like its parent compound, tetracycline hydrochloride inhibits bacterial protein synthesis by binding to the bacterial ribosome, exerting bacteriostatic effects against a wide range of gram-positive and gram-negative bacteria, as well as certain protozoa.