Physical stability of cholesterol derivatives combined with liposomes and their in vitro behavior.

The purpose of this study was to investigate the physical stability and drug release of two cholesterol derivatives (4-cholesterocarbonyl-4'-(N,N,N-triethylamine butyloxyl bromide, CTBBA, and 4-cholesterocarbonyl-4'-(N,N'-diethylamino-butyloxy, CDBA), when combined with doxorubicin (DOX)-loaded liposomes in vitro. CTBBA-liposome revealed a positive charge at a pH between 3 and 10, as indicated by the ζ-potential. DOX-encapsulated CTBBA-liposomes possessed better physical stability both in PBS and in fetal bovine serum (FBS) added to PBS.