Pharmacokinetics of tetracycline encapsulated in bovine carrier erythrocytes.

Tetracycline was encapsulated in erythrocytes with a dialysis technique. The effect of drug concentration (0.2 mg/ml of erythrocytes) on encapsulation of [14C]sucrose and [3H]tetracycline was reduction of the tetracycline encapsulation, but not [14C]sucrose. Carrier erythrocytes containing tetracycline reinjected in calves were studied for their pharmacokinetic constants. The drug half-life was 6.7 hours, with an overall elimination constant of 0.104 hour-1.