Studies On The Preparation and Characterization Of Thermosensitive Liposomes
Thermosensitlve liposomes prepared from synthetic lipids such as dipaltmitoyl phosphatidyl chollne (DPPC), distearoyl phosphatidyl choline (DSPC) and cholesterol (CH) have been tried for local drug release in response to hyperthermia for achieving tumor drug targeting. Herein we report the use of natural lipid, soyabean lipid (SPC) and cholesterol (CH) to prepare thermosensitive liposomes. When liposomes are prepared by reverse evaporation method, It was found that most of the particles are multilamellar small vesicles. In vitro dialysis method was used to study the behavior of the liposomes made from different ratios of SPC and CH after the anticancer drug [2,4 (1H, 3H)-pyrimidine] (5-FU) fluorouracil was entrapped. From the result, it was found that, when the ratio of SPC and cH is proper (8:1), the liposomes made from them release most of the entrapped drug at 40o and the differential scanning calorimetry (DSC) showed that the liquid crystalline transition temperature (Tm) of the liposomes is about 40Â° too.