PREPARATION OF METHOTREXATE (MTX)-LIPOSOMES AND THEIR STABILITY

In this paper, factors affecting the encapsulation ratio of MTX with lipo-somes and their stability to heating were studied. A fast and reproducible method for determining MTX-liposomes is established. The results suggest that with double emusification evaporation method, MTX-liposomes with a 50% higher encapsulation ratio can be obtained by controlling the temperature during emulsification and the ratio of the organic solvents. The ionic strength of liposome suspension and cholesterol content in liposomes are important factors affecting MTX-liposome stability to heat.Selecting 50 mM phosphate buffer solution as the solvent of MTX-liposomes and the lipid composition of 7 PC/2 CHOL/1 SA (with molar ratios preceding), 90% of entrapped MTX was retained after sterilization at 100℃ for 30 min.