Pharmacokinetics (PK) of a liposomal encapsulated fraction containing doxorubicin and of doxorubicin released from the liposomal capsule after intravenous infusion of Caelyx™/Doxil®.

The article cites a research study that investigates the plasma levels as well as the cellular up take of encapsulated and free doxorubicin. Caelyx was administered i.v. to patients with different refractory malignancies. Also spontaneous urine fractions were collected and the volume of each fraction were analyzed. Toxicity of doxorubicin may preclude adequate dosing and diminish its therapeutical effect on relapse, or lead to drug resistance. Amount of doxorubicin in the liposomes exceeds the water solubility of doxorubicin.