Preparation of doxifluridine liposome

Objective: To develop a procedure for preparation of doxifluridine (DFUR) liposomes. Methods: DFUR liposome was prepared by reverse phase evaporation technique, and the preparation procedure was optimized by orthogonal test using encapsulation efficiency as a reference index. The DFUR liposome prepared by the optimized procedure was observed for micromorphology, determined for particle size, encapsulation efficiency and stability, and subjected to release test in vitro. Results: The optimal molar ratio of ovolecithin to cholesterol, volume ratio of organic phase to aqueous phase, DFUR concentration and pH value of PBS for preparation of DFUR liposome were 2:1, 5:1, 2 mg/ml and 7.0 respectively. The encapsulation efficiency of DFUR liposome prepared by the optimal formula reached 52.15%. All the percentages of particles at sizes of less than 220 nm in 3 batches of DFUR suspension were more than 70%. The prepared DFUR liposome was spherical or oval particles at sizes of 0.15-1.00 μm under microscope, and showed good stability after storage at 4°C for 49 d. The cumulative release rate of prepared DFUR liposome was far lower than that of DFUR solution as a material. Conclusion: A simple, reliable and stable procedure for preparation of DFUR liposome was developed, which needed only simple equipments and was suitable for embedding water-soluble drugs.