1993 Volume 16 Issue 10 Pages 965-969
The efficiency of encapsulation of doxorubicin (DOX) into liposomes containing HCO60 was studied. Empty egg phosphatidylcholine (PC) liposomes containing various amounts of HCO60 were passed through a polycarbonate membrane filter (0.1 μm). Closed vesicles were formed even with liposomes containing 90 wt% HCO60. DOX was encapsulated efficiently (more than 1 mg DOX/8 mg lipids) using a pH-gradient method. HCO60 accelerated the leakage of DOX from liposomes into phosphate buffer at temperatures above 25°C. HCO60 suppressed the leakage of DOX from egg PC/cholesterol (7/3, w/w) liposomes into phosphate buffer containing 50% fetal bovine serum (FBS). Studies on the interaction between liposomes and serum components using zeta potential and turbidity suggest that HCO60 prevents the liposomes from interacting with serum components.