Glutaraldehyde-treated carrier erythrocytes for organ targeting of methotrexate in dogs.

Chemotherapeutic doses of methotrexate (MTX) were encapsulated in as little as 1 ml of canine carrier erythrocytes. Carrier erythrocytes prepared by a dialysis technique contained more than 3.0 mg of MTX/ml of cells. In vivo pharmacokinetic studies indicated that most of the drug leaked from the circulating MTX-loaded erythrocytes. In dogs, glutaraldehyde treatment of MTX-loaded erythrocytes prevented drug leakage and targeted more than 50% of the drug to the liver.