Tetracycline Degradation Products in Commercially Available Tetracycline-7-3H

Enterohepatic Circulation of Tetracycline in Rats

“…The report by Lanman et al (20) on the purity of tritiated tetracycline hydrochloride samples available commercially instigated a thorough examination of the purity of the samples used in the present study. These workers found that two commercially available radioactive samples contained only 5 0 4 0 % pure tetracycline hydrochloride; the rest consisted of the degradation products, anhydrotetracycline and 4-epitetracycline.…”

“…(20). Usually, these tracers are mixed with nonlabeled, chemically pure materials which may behave differently in the biological system.…”