Development of Liposomal Formulation of A Camptothecin Derivative

캄프토테신 유도체의 리포좀 제형 개발

CKD602, a camptothecin derivative, is a synthetic and water-soluble anticancer agent possessing of topoisomerase I inhibiting activity. DPPC and DSPE-PEG liposomal formulations entrapped with CKD602 were developed. DSPE-PEG liposome, or PEGylated liposome, encapsulating CKD602 composed of dipalmitoylphosphatidylcholine (DPPC), cholesterol and distearoyl-N-monoethoxy poly (ethyleneglycol) succinylphosphatidylethanolamine $(DSPE-PEG_{2000})$ (22:11:2) was prepared by reverse-phase evaporation method. Formed liposomes were characterized in terms of the morphology, size and encapsulation efficiency. To elucidate the in vitro stability, PEGylated liposome was incubated in human plasma, and the adsorbed proteins onto the surface of liposomes were applied to the SDS-PAGE. In vitro cytotoxicity of CKD602 encapsulated in PEGylated liposome was studied in human cervical cancer cell line (HeLa). CKD602 in PEGylated liposome was found to be 40-fold more effective $(IC_{50}=1\;nM)$ than free CKD602 $(IC_{50}=40\;nM)$ in inhibiting the growth of HeLa cells in vitro.