CONCENTRATION AND PERSISTENCE OF TETRACYCLINE AND CHLORTETRACYCLINE IN BONE

¹ Experimental Therapeutics Research, Lederle Laboratories, American Cyanamid Company, Pearl River, New York

A quantitative study on the adsorption of tetracycline and chlortetracycline by bone and the effects of dosage levels and routes of administration was carried out. Both chemical and radiochemical methods were employed. The bones of rats receiving a single high oral dose retained only small amounts of antibiotic. A cumulative deposition was noted for animals on long-term drug-diet regimes but no deleterious effects were recorded. Single intravenous and intraperitoneal administrations indicate that the retention was an immediate consequence of the physical contact of the antibiotic with bone and that, once deposited, a portion was retained for long time intervals.

The heretofore little recognized function of bone as a depot site for a drug and the contribution of this deposition to the dynamics of retention of the drug in the body is noted.