The liposomes have {HEAD ~ an inside/outside ion gradient} sufficient to retain the topoisomerase I inhibitor or topoisomerase I/II inhibitor within the liposomes at {TAIL ~ the specified concentration} 
The liposomes have { HEAD ~ an inside / outside ion gradient } sufficient to retain the topoisomerase I inhibitor or topoisomerase I / II inhibitor within the liposomes at { TAIL ~ the specified concentration }
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL