The invention relates to methods for obtaining liposomes externally modified with a targeting peptide able to selectively drive liposomal doxorubicin on membrane receptors over expressed in tumours.

The invention is based on a kit containing a first vial filled with a sterile, translucent, red dispersion of the liposomal doxorubicin drug; a second vial filled with a modified phospholipid with a reactive function such as DSPEPegmaleimide in lyophilized form; and a third vial filled with a peptide modified with an appropriate reactive function, in a 1:1 stoichiometric amount respect to modified phospholipid and in lyophilized form.

The kit could also contain an additional fourth vial with the targeting peptide modified with a chelating agent able to complex radioactive metal ions for diagnostic and imaging purposes. The patients to be treated with the peptide modified liposomal doxorubicin could be selected on the basis of the over expression of the targeting receptors.