Study On TJ121Liposomes

TJ121is extracted from camptotheca acuminata Decaisne. It has no acrossresistance with other anti-tumor drug. It’s useful for us to research it. This studyaimed to prepare an injection of TJ121liposomes which can improve its solubilityand protect its pharmacophore, thus increasing efficacy. The TJ121liposomes werestable for long-term storage.A Phosphatidylcholine was used as the carrier while B was used as membranemodifiers during the formulation design and preparation techniques of TJ121liposomes.TJ121liposmes were produced by flim-supersonic dispersion method aftercarrier choice. Besides, high pressure homogenize method could reduce TJ121liposomes of partical size. We have done something to obtain the optimized. Forexample, we apply single factor test and the orthogonal design. So we got a betterprescription. It was that the concentration of TJ121was0.5mg/ml, the ratio of drugand lipid was1:12(W/W), B concentration was0.5%, the pH was adjusted to about6.5. Final liposomes was carried out through a high pressure homogenizer, we havemade a conclusion that ten times at a pressure of800bar could get better TJ121liposomes. The optimized liposomes was of uniform particle size and the EE%couldexceed95％.It’s unstable for liposomes in water environment, it’s easy to case drug leakage,phospholipid hydrolysis and so on. In order to improve stability and extend thestorage period, we would apply freeze drying technology to solve the problem.Weoptimize the process and lyoprotectant.The result showed that7.5%C and7.5%Dwere the suitable lyoprotectant. The liposomes were freezed at-20℃for24h duringthe lyophilization process, then lyophilized for36h. The particle size varied littlebefore and after lyophilization.We also research the physicochemical properties and stability of TJ121 liposomes.It fit for requirement of intracenous injection. The freeze-dried stored in4℃would keep TJ121structure stably. We also investigated the stablity of the threeblock medium amplified preparation, including stressing testing (illumination, hightemperature and high moisture). The results of stressing showed the TJ121liposomesare unstable under illumination and high moisture.So we should keep the TJ121liposomes avoiding light and dry-storage.