Reduced UV-induced degradation of doxorubicin encapsulated in polyethyleneglycol-coated liposomes.
OBJECTIVE
The aim of this study was to investigate the stability of doxorubicin encapsulated in polyethyleneglycol-coated liposomes (Doxil) under UV-A light.


METHODS
High performance liquid chromatography and a fluorimetric method were used to quantify doxorubicin in bulk solution and doxorubicin in Doxil formulation.


RESULTS
The photodegradation of Doxil was significantly lower in comparison to the photodegradation of the free drug and showed no concentration dependency at the measured concentration range of 5-50 microg/ml. During and after UV-A irradiation, there was no leakage of the drug from liposomes to the medium. After induced leakage of doxorubicin from the liposomes by the ionophore nigericin, the degradation kinetics of Doxil were identical to that of free doxorubicin.


CONCLUSIONS
High intraliposomal doxorubicin concentration and intraliposomal acidic pH are the two critical factors that protect DXR in Doxil from UV-A degradation.
Bandak
S
S
Sharet Institute of Oncology, Hadassah Hebrew University Medical Center, Jerusalem, Israel. suzan@md2.huji.ac.il
Ramu
A
A
Barenholz
Y
Y
Gabizon
A
A
D000970:Antineoplastic Agents / Q000378:metabolism / Q000528:radiation effects*; D002214:Capsules; D004317:Doxorubicin / Q000378:metabolism / Q000528:radiation effects*; D004337:Drug Carriers / Q000528:radiation effects; D008081:Liposomes / Q000528:radiation effects; D010714:Phosphatidylethanolamines / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D014466:Ultraviolet Rays
D000970:Antineoplastic Agents; D002214:Capsules; D004337:Drug Carriers; D008081:Liposomes; D010714:Phosphatidylethanolamines; C107570:polyethylene glycol-distearoylphosphatidylethanolamine; D011092:Polyethylene Glycols; D004317:Doxorubicin