Objective: To prepare two different liposome gels containing podophyllotoxin (PPT) and compare their pharmaceutical properties.
Methods: PPT-Dipalmitoylphosphatidylcholine (DPPC) liposome and PPT-soya lecithin liposome were prepared by reverse phase evaporation technique, and optical and electron microscopy were performed respectively for examining the appearances of the 2 liposomes and the diameter of the particles. Gel filtration was employed to assess the embedding ratio of the liposomes.
Results: Under optical microscope, PPT-DPPC liposome was observed to be composed of spherical particles with diameter range of 2.05 to 0.825 microm (average 1.45 microm). The diameter range of the particles of PPT-soya lecithin liposome is 7.59 to 1.445 microm (average 3.78 microm). PPT-DPPC liposome appeared multivesicular under electron microscope, with the embedding ratio of 73.8%, and 79.1% for PPT-soya lecithin liposome (n=3). PPT-DPPC liposome had a embedding ratio of 65.2%, 58.8% and 56.4% after preserved 1, 3, 6 months respectively. As for PPT-soya lecithin liposome, the embedding ratios were 70.3%, 60.4%, and 51.3% respectively.
Conclusion: The PPT in the liposomes prepared by reverse phase evaporation technique is evenly distributed throughout the gel. The preparation is relatively simple with high embedding ratio.