Study on preparation and tissue distribution of hydroxycamptothecin liposomes

Abstract

To develop HCPT liposome with small diameter and to study the tissue distribution of the HCPT liposome in rats. Modified solvent-injection method was used to prepare HCPT liposome. The entrapment efficiency, morphology, size and zeta potential were also investigated. The transformation temperature and the ratio of cholesterol to phospholipids were determined by fluorescence spectrophotometry. HCPT liposome and HCPT injection (5 mg x kg(-1)) were injected by tail vein in mice, respectively. The tissue concentrations of HCPT were determined by LC-MS/MS. Under selected process conditions, the HCPT liposomes were spherical and integrated with the mean entrapment efficiency of (96.83 +/- 2.32)%, the size of (180.5 +/- 4.5) nm and the zeta potential of--(32.1 +/- 1.3) mV. It showed that the optimum proportion of cholesterol to phospholipids was 1.5: 10, the optimum transformation temperature was 32.5 degrees C; HCPT liposome at a dose of 5 mg x kg(-1) led to higher concentration and longer duration of action compared with HCPT injection on market. HCPT liposome prepared by solvent-injection method was characteristic of small mean diameter, high encapsulation efficiency and long circulation in vivo.