Lo Yu-li, Tsai Jui-chen, Kuo Jung-hua
Department of Pharmacy, Chia-Nan University of Pharmacy and Science, Tainan Hsien, 717, Taiwan, ROC.
J Control Release. 2004 Feb 10;94(2-3):259-72. doi: 10.1016/j.jconrel.2003.09.019.
In this study, we aim to investigate the effects of disaccharides and liposome carriers on the activity, solid state characteristics, structural preservation, and aerosol powder performance of spray-dried superoxide dismutase (SOD) formulations. Sucrose, trehalose, and lactose were selected as stabilizing adjuvants in the spray-drying process. Dipalmitoyl phosphatidylcholine (DPPC) was the major lipid component for preparing liposomes. These SOD formulations were characterized with SOD activity assay, particle size, residual moisture content, scanning electron microscopy (SEM), electron spectroscopy for chemical analysis (ESCA), differential scanning calorimeter (DSC), and Fourier transform infrared (FT-IR) spectroscopy. We found that the inlet/outlet temperature of spray drying can be performed up to 168/122 degrees C with maintaining the activity of SOD in the SOD\DPPC\sucrose formulation for 98%. The SEM image of this formulation showed wrinkled and raisin-like appearance. Aerosol powder performance test demonstrated that this formulation exhibited excellent emitted dose (ED, 71%), aerodynamic diameter (2 microm), and respirable fraction (RF, 72%). DSC study suggested an indication of initial electrostatic stabilization of SOD by DPPC and sucrose, the following lipid perturbation by SOD, and the formation of an inclusion complex, thus minimizing the individual transition peaks of SOD and DPPC. FT-IR study showed that the major secondary structure of SOD, beta-sheet, was maintained in this formulation. The surface ESCA analysis of this formulation suggested the absence of SOD on the surface region of the powders, indicating that SOD was well surrounded and protected by DPPC and sucrose. Spray drying has been demonstrated to be a feasible process to preserve the activity of SOD in the formulation of DPPC liposomes with sucrose.
在本研究中，我们旨在研究二糖和脂质体载体对喷雾干燥超氧化物歧化酶（SOD）制剂的活性、固态特性、结构保存及气溶胶粉末性能的影响。在喷雾干燥过程中，选择蔗糖、海藻糖和乳糖作为稳定佐剂。二棕榈酰磷脂酰胆碱（DPPC）是制备脂质体的主要脂质成分。这些SOD制剂通过SOD活性测定、粒度、残留水分含量、扫描电子显微镜（SEM）、化学分析电子能谱（ESCA）、差示扫描量热仪（DSC）和傅里叶变换红外（FT-IR）光谱进行表征。我们发现，喷雾干燥的进/出口温度可达168/122摄氏度，同时SOD\DPPC\蔗糖制剂中SOD的活性可保持98%。该制剂的SEM图像显示出皱纹状和葡萄干样外观。气溶胶粉末性能测试表明，该制剂表现出优异的发射剂量（ED，71%）、空气动力学直径（2微米）和可吸入分数（RF，72%）。DSC研究表明，DPPC和蔗糖对SOD有初始静电稳定作用，随后SOD引起脂质扰动，并形成包合物，从而使SOD和DPPC的各个转变峰最小化。FT-IR研究表明，该制剂中SOD的主要二级结构β-折叠得以保留。该制剂的表面ESCA分析表明，粉末表面区域不存在SOD，这表明SOD被DPPC和蔗糖很好地包围和保护。喷雾干燥已被证明是一种在含蔗糖的DPPC脂质体制剂中保存SOD活性的可行方法。
