Shulkin P M, Seltzer S E, Davis M A, Adams D F
Department of Radiology, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts 02115.
J Microencapsul. 1984 Jan-Mar;1(1):73-80. doi: 10.3109/02652048409031539.
To facilitate acceptance and use of radiopaque liposomes as novel CT contrast agents, we developed a technique that permits their long-term storage at room temperature. This study compares standard storage procedures with the new method. Multilamellar vesicles were prepared with egg lecithin, cholesterol and stearylamine (4:1:1 molar ratio) as well as diatrizoate. After synthesis, the vesicles were separated into batches: one portion was kept frozen (FRO), another was lyophilized and stored at room temperature (LYO-RT), and a third was thawed and stored at room temperature (RT). Size, structure and biodistribution of vesicles in all three groups were assessed over a 6-month period. Freeze-drying the vesicles caused no apparent damage to their membranes The RT group showed marked aggregation after 1 month, while the LYO-RT and FRO vesicles showed only a slight shift to larger particles after 6 months. At this time, there was no significant change in the biodistribution of the LYO-RT vesicles compared to FRO. Uptakes in the reticuloendothelial tissues were 15 per cent and 19 per cent respectively. The LYO-RT materials showed additional advantages in that they were always easy to resuspend. This technique appears to be the most successful and convenient procedure for the long-term storage of liposomes.
为促进不透射线脂质体作为新型CT造影剂的接受和使用，我们开发了一种能使其在室温下长期储存的技术。本研究将标准储存程序与新方法进行了比较。用卵磷脂、胆固醇和硬脂胺（摩尔比4:1:1）以及泛影酸盐制备了多层囊泡。合成后，将囊泡分成几批：一部分冷冻保存（FRO），另一部分冻干后在室温下保存（LYO-RT），第三部分解冻后在室温下保存（RT）。在6个月的时间里评估了所有三组囊泡的大小、结构和生物分布。冻干囊泡对其膜没有造成明显损伤。RT组在1个月后出现明显聚集，而LYO-RT和FRO囊泡在6个月后仅向较大颗粒有轻微偏移。此时，与FRO相比，LYO-RT囊泡的生物分布没有显著变化。网状内皮组织的摄取率分别为15%和19%。LYO-RT材料还具有其他优点，即它们总是很容易重新悬浮。该技术似乎是脂质体长期储存最成功、最方便的方法。
