Vision Institute IPEPO, Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil.
Ophthalmologica. 2013;230 Suppl 2:59-67. doi: 10.1159/000353871. Epub 2013 Sep 6.
To investigate pH, ions, osmolarity and precipitation of indocyanine green (ICG), as well as the profile of ICG decomposition products (DPs) after laser exposure and the interaction with quenchers.
ICG was diluted in water, 5% glucose (GL) or balanced salt solution (BSS) to achieve concentrations of 2.5, 1, 0.25 and 0.1 mg/ml. Osmolarity, pH and precipitation were analyzed immediately and after 24 h. Precipitation analyses were done with a scanning electron microscope. Anion and iodate analyses of ICG and infracyanine green (IfCG) were performed by capillary zone electrophoresis. With regard to DPs, 0.5 mg/ml of ICG was assessed with high-performance liquid chromatography (HPLC) after 810-nm laser irradiation. DP profiles were evaluated with ICG dilution in quenchers (Trolox, histidine and DABCO) in 3 concentrations (0.1, 1 and 10 M).
BSS promoted iso-osmotic ICG solutions of 208 mOsm (147-266) compared to GL with 177 mOsm. BSS solutions had a higher physiological pH of 7.2 compared with the GL one of 6.55. ICG precipitated more when diluted with BSS (5.95 mg); in contrast, GL showed less precipitate (3.6 mg). IfCG has no iodine derivates and other ICGs have an average 4.6% of iodate derivates. From HPLC analysis, 5 DPs were observed. The rate of DPs was higher when BSS was used (p < 0.05). Five DPs have been generated with ICG, and they may be altered with the quenchers DABCO, histidine and Trolox.
BSS dilution induces more precipitation and DPs. ICG dilution in any solvent induces DPs. Quencher use reduces the amount of toxic DPs.
研究激光照射后吲哚菁绿（ICG）的 pH 值、离子、渗透压和沉淀，以及 ICG 分解产物（DP）的形成情况，并探讨其与猝灭剂的相互作用。
将 ICG 稀释于水、5%葡萄糖（GL）或平衡盐溶液（BSS）中，使其浓度分别达到 2.5、1、0.25 和 0.1mg/ml。分别于即刻和 24 小时后分析渗透压、pH 值和沉淀。利用扫描电子显微镜进行沉淀分析。采用毛细管区带电泳法对 ICG 和次菁绿（IfCG）中的阴离子和碘酸盐进行分析。采用高效液相色谱法（HPLC）对 0.5mg/ml 的 ICG 进行评估，在 810nm 激光照射后。用不同浓度（0.1、1 和 10M）的猝灭剂（Trolox、组氨酸和 DABCO）对 ICG 进行稀释，评估 DP 谱。
与 GL（渗透压 177mOsm）相比，BSS 可使 ICG 形成等渗溶液，渗透压为 208mOsm（147-266）。BSS 溶液的生理 pH 值为 7.2，高于 GL（pH 值为 6.55）。当用 BSS 稀释时，ICG 沉淀更多（5.95mg）；而 GL 显示出较少的沉淀（3.6mg）。IfCG 不含碘衍生物，其他 ICG 含有平均 4.6%的碘酸盐衍生物。HPLC 分析显示，观察到 5 种 DP。当使用 BSS 时，DP 生成速度更高（p<0.05）。用 ICG 生成了 5 种 DP，它们可能会与猝灭剂 DABCO、组氨酸和 Trolox 发生变化。
BSS 稀释会导致更多的沉淀和 DP 形成。ICG 在任何溶剂中的稀释都会产生 DP。猝灭剂的使用可减少毒性 DP 的产生。
