Formulasi baru liposom tetraeter lipid (EPC-TEL 2,5) hasil sonikasi dan stabilitasnya dalam larutan NaCL dan MgCl2 150 mOsm pH 7 = A novel formulation of liposome tetraether lipid (EPC-TEL 2,5) after sonication and their stabilities in NaCl and MgCl2 150 mOsm neutral solution