Studies On Vinorelbine Bitartrate Liposome

The method of reverse-phase high performance liquid chromatography (RP-HPLC) for the concentration of Vinorelbine Bitartrate (NVB) in vitro was developed. The HPLC method for the content of NVB in liposomes was established. The apparent partition coefficient in n-octyl alcohol/water was determined by HPLC. The entrapment efficiency of NVB liposome was determined by microcolumn centrifuge, destroyed by methanol and HPLC for the contents. The method is simple, rapid, acute, sensitive, reproducible and suitable for the quality control of NVB liposomes.Aimed at high encapsulation effiency(EE), the NVB liposome was prepared by ethanol injection method and active loading method. The single factor investigation and the orthogonal design were adopted to obtain the optimized prescription, the entrapment efficiency of NVB liposome was above 90%. Also we found method to study the vitro release profile of NVB liposome and got the aimed NVB liposome.The physicochemical properties of NVB liposome were studied. The liposome was spheroidal and uniform, the volume, number diameters and surface area diameters of NVB liposome were (161±23) nm, (151±21)nm)and (157±22) nm respectively, the Zeta potential of these were suitful for stable; the pH value was not changed notably, closed to 3.98; the entrapment efficiency of were (90.14±1.04)%The security investigation indicated that the NVB liposome injection was non-irritant, pyrogen-free and non-hematolytic, the preparation met the regulations of the iv administration.Dilution test revealed that the samples diluted with glucose injection (5%) and sodium chloride injection (0.9%) show good stability. When the dilution multiple was 3, there was stable absorption.The results of stability tests indicated that the NVB liposomes should be tightly preserved from light and stored at low temperature.The stability test showed that NVB liposome showed no significant change after 6 months under 6±2℃.The assay of anticancer activity in vitro demonstrate that the anticancer activity of NVB liposome was at most equivalent to NVB solution because of NVB slowly released from liposome, but the anticancer activity was dose-dependent in A549 and MCF-7 tumor cells.The assay of anticancer activity in vitro demonstrate that the anticancer activity of NVB liposome combined with Verapamil showed excellent anticancer activity than NVB liposome in MCF-7 tumor cells. Verapamil, a P-gp inhibitor, sustained inhibition of P-gp leading to sustaining cytotoxity of liposome-encapsulated NVB in drug-resistent MCF-7 tumor cells.