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Oxytetracycline is a tetracycline analog isolated from the actinomycete Streptomyces rimosus. Oxytetracycline is an antibiotic indicated for treatment of infections caused by Gram positive and Gram negative microorganisms such as Mycoplasma pneumoniae, Pasteurella pestis, Escherichia coli, Haemophilus influenzae, and Diplococcus pneumoniae. It is used in studies on the oxytetracycline-resistance gene (otrA). Oxytetracycline hydrochloride is used to study phagosome-lysosome (P-L) fusion in P388D1 cells and antibiotic susceptibilities of Mycoplasma bovis isolates.
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Yellow Crystalline Solid
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Oxytetracycline hydrochloride is a salt prepared from oxytetracycline taking advantage of the basic dimethylamino group which protonates readily to form the salt in hydrochloric acid solutions. The hydrochloride is the preferred formulation for pharmaceutical applications. Like all tetracyclines, oxytetracycline shows broad spectrum antibacterial and antiprotozoan activity and acts by binding to the 30S and 50S ribosomal sub-units, blocking protein synthesis.
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Oxytetracycline hydrochloride appears as odorless fluffy yellow solid or yellow powder. Bitter taste. (NTP, 1992)
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Early in 1950, Finlay et al.182 reported the isolation of oxytetracycline(Terramycin) from S. rimosus. This compoundwas soon identified as a chemical analog of chlortetracycline that showed similar antibiotic properties. The structureof oxytetracycline was elucidated by Hochstein et al.183 andthis work provided the basis for the confirmation of thestructure of the other tetracyclines.
Oxytetracycline hydrochloride is a pale yellow, bitter,crystalline compound. The amphoteric base is only slightlysoluble in water and slightly soluble in alcohol. It is odorlessand stable in air but darkens on exposure to strong sunlight.The hydrochloride salt is a stable yellow powder that ismore bitter than the free base. It is much more soluble inwater, 1 g dissolving in 2 mL, and more soluble in alcoholthan the free base. Both compounds are inactivated rapidlyby alkali hydroxides and by acid solutions below pH 2. Bothforms of oxytetracycline are absorbed rapidly and equallywell from the digestive tract, so the only real advantage thefree base offers over the hydrochloride salt is that it is lessbitter. Oxytetracycline hydrochloride is also used for parenteraladministration (intravenously and intramuscularly).
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Oxytetracycline hydrochloride is hygroscopic. Water soluble. Undergoes slow hydrolysis in the presence of water. Concentrated aqueous solutions at neutral pH hydrolyze on standing.
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Oxytetracycline hydrochloride is sensitive to light. Oxytetracycline hydrochloride may be unstable at temperatures above 77° F. Oxytetracycline hydrochloride darkens on exposure to sunlight or to moist air above 194° F. Concentrated aqueous solutions at neutral pH hydrolyze on standing. Oxytetracycline hydrochloride undergoes hydrolysis in the presence of water. Oxytetracycline hydrochloride may be incompatible with alkalis.
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Flash point data for Oxytetracycline hydrochloride are not available. Oxytetracycline hydrochloride is probably combustible.
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