Liposomal doxorubicin is a cytotoxic anthracycline antibiotic. Liposomal doxorubicin binds with DNA and inhibits nucleic acid synthesis. The uniqueness of this form of doxorubicin is that it is encapsulated in long-acting STEALTH® liposomes composed of phospholipid that help to protect the drug from detection by the mononuclear phagocyte system. This allows the drug to circulate longer in the system and penetrate the altered, and often compromised, vasculature of tumors.