The present invention relates to phospho-lipid compounds of formula ##STR1## having solubilizing activity for water-insoluble or poorly water soluble active agents and their use in the delivery of active agents to cells and in the treatment of diseases, i.e., cancer and protozoal diseases. The compounds also exhibit direct therapeutic effects on some diseases. The inventive compounds can be formulated into liposomes containing phospholipids, alkylphospholipids and/or cholesterol. The compounds of the present invention may be prepared by reacting primary and secondary amines with epoxides.