Delivery of therapeutic doses of doxorubicin to the mouse lung using lung-accumulating liposomes proves unsuccessful.

Addition of solid doxorubicin or solutions to pre-formed liposomes proved to be the optimal method for incorporating the drug into liposomes whilst maintaining their size distribution and hence ability to accumulate in the lung. Liposomes prepared in this way lost doxorubicin only slowly on dialysis but dilution with an equal volume of saline at 37 degrees C resulted in the loss of 80% of the incorporated doxorubicin within 30 min. These liposomes were thus ineffective in altering doxorubicin disposition in vivo and produced no enhanced activity compared with free drug and a non-lung-accumulating carrier liposome in the EMT6 cell-Balb/c mouse model lung tumour.