Li C, Kan Z, Yang D J, Kuang L R, Liu C W, Wright K C, Wallace S
Division of Diagnostic Imaging, University of Texas M.D. Anderson Cancer Center, Houston 77030.
Invest Radiol. 1994 Nov;29(11):1006-13. doi: 10.1097/00004424-199411000-00010.
To prepare and characterize a new particulate contrast medium, cyclic carbonate of ioxilan (IX-C) particles, as a macrophage imaging agent for computed tomography (CT) enhancement of the liver.
Cyclic carbonate of ioxilan was synthesized from ioxilan, a nonionic water-soluble contrast agent. The IX-C particles prepared by a solvent extraction-evaporation method were characterized by size distribution, degradability, suspension stability, and median lethal dose. Pharmacokinetics of IX-C particles and their effectiveness in enhancing liver attenuation and in detecting hepatic tumors were evaluated using normal and VX2-tumor-bearing rabbits.
The IX-C particles were biodegradable, with ioxilan and carbon dioxide as the degradation products. The particles had an average size of 1 to 2 microns and were stable in saline suspension. The median lethal dose determined for IX-C particles was 2.6 and 3.1 g/kg body weight for female and male rabbits, respectively. A dose of 200 mg iodine/kg body weight caused an increase of 38 Hounsfield units in liver attenuation. In rabbit, hepatic clearance of the contrast medium occurred in 2 days. A tumor barely visible in precontrast scans could be detected after contrast injection.
Development of particulate contrast medium from nonionic contrast agents represents a new approach. Ioxilan carbonate particles have suitable physicochemical properties that warrant further studies before clinical evaluation.
制备并表征一种新型微粒造影剂——碘克沙醇环碳酸酯（IX-C）微粒，作为用于计算机断层扫描（CT）增强肝脏的巨噬细胞成像剂。
碘克沙醇环碳酸酯由非离子水溶性造影剂碘克沙醇合成。采用溶剂萃取-蒸发法制备的IX-C微粒通过粒径分布、可降解性、混悬稳定性和半数致死量进行表征。使用正常和荷VX2肿瘤的兔子评估IX-C微粒的药代动力学及其增强肝脏衰减和检测肝肿瘤的有效性。
IX-C微粒可生物降解，降解产物为碘克沙醇和二氧化碳。微粒平均粒径为1至2微米，在生理盐水混悬液中稳定。IX-C微粒对雌性和雄性兔子测定的半数致死量分别为2.6和3.1 g/kg体重。200 mg碘/kg体重的剂量可使肝脏衰减增加38亨氏单位。在兔子中，造影剂在2天内从肝脏清除。造影剂注射后可检测到造影前扫描中几乎不可见的肿瘤。
由非离子造影剂开发微粒造影剂是一种新方法。碘克沙醇碳酸酯微粒具有合适的理化性质，在临床评估前值得进一步研究。
