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