Bohrer Denise, Bortoluzzi Fabiana, Nascimento Paulo Cícero, Carvalho Leandro Machado, Ramirez Adrian Gustavo
Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil.
Int J Pharm. 2008 May 1;355(1-2):174-83. doi: 10.1016/j.ijpharm.2007.12.025. Epub 2007 Dec 24.
Glass is made of polymeric silica and other minor components, which are necessary for turning the silica into a material more easily moldable and resistant to temperature changes. Glass containers for pharmaceutical usage are classified according to their resistance to a chemical attack, a test carried out in the presence of water and heat. The test is designed to show the released alkalinity, a variable dependent on the amount of sodium oxide, one of the minor components added to the glass mass. In this work, the release of silica from glass by action of constituents from pharmaceutical formulations was investigated. The study included products used in large volumes and usually stored in glass containers. Solutions of amino acids, electrolytes, glucose, oligoelements and others such as heparin and sodium bicarbonate were individually stored in glass containers and heated at 121 degrees C for 30min, as in the water attack test. The test was also carried out only with water, where the pH varied from 2 to 12. The released silicate was measured either by photometry or atomic absorption spectrometry, depending on the nature of the sample. The results showed that silicate is released during the heating cycle even if the contact is with pure water only. The pH exerts a considerable influence on the release, being that the higher the pH, the higher the silica dissolved. An elevated pH, however, is not the only factor responsible for silica dissolution. While in the solutions of NaCl, KCl, Mg Cl2 and ZnSO4 and in most of the amino acids, the concentration of silicate was as high as in pure water (0.1-1.0mg Si/L). In the solutions of sodium acetate, bicarbonate and gluconate, its concentration was much higher, over 30mg Si/L. These results were confirmed by the analysis of commercial products, where in solutions of amino acids the level of silicate ranged from 0.14 to 0.19mg Si/L. On the other hand, calcium gluconate, sodium bicarbonate and potassium phosphate presented silicate levels from 1 to 4mg/L. Although silica is not considered a toxic substance for humans, it is necessary to be aware of its presence in solutions for parenteral nutrition due to the direct introduction into the bloodstream and the large volume usually administrated, even to pre-term infants.
玻璃由聚合二氧化硅和其他微量成分制成，这些成分对于将二氧化硅转变为更易于成型且耐温度变化的材料是必需的。药用玻璃容器根据其耐化学侵蚀性进行分类，这种测试是在有水和热的条件下进行的。该测试旨在显示释放出的碱度，这一变量取决于氧化钠的含量，氧化钠是添加到玻璃原料中的微量成分之一。在这项工作中，研究了药物制剂成分作用下玻璃中二氧化硅的释放情况。该研究涵盖了大量使用且通常储存在玻璃容器中的产品。氨基酸、电解质、葡萄糖、微量元素以及其他物质（如肝素和碳酸氢钠）的溶液分别储存在玻璃容器中，并按照水侵蚀测试的方式在121摄氏度下加热30分钟。该测试也仅用水进行，水的pH值在2至12之间变化。根据样品的性质，通过光度法或原子吸收光谱法测量释放出的硅酸盐。结果表明，即使仅与纯水接触，在加热循环过程中也会释放出硅酸盐。pH值对释放有相当大的影响，即pH值越高，溶解的二氧化硅越多。然而，高pH值并非导致二氧化硅溶解的唯一因素。在氯化钠、氯化钾、氯化镁和硫酸锌溶液以及大多数氨基酸溶液中，硅酸盐的浓度与纯水中的浓度一样高（0.1 - 1.0毫克硅/升）。在醋酸钠、碳酸氢盐和葡萄糖酸盐溶液中，其浓度要高得多，超过30毫克硅/升。这些结果通过对商业产品分析得到证实，在氨基酸溶液中，硅酸盐水平在0.14至0.19毫克硅/升之间。另一方面，葡萄糖酸钙、碳酸氢钠和磷酸钾的硅酸盐水平为1至4毫克/升。尽管二氧化硅对人类不被视为有毒物质，但由于其直接进入血液循环且通常大量给药，甚至对早产儿也是如此，所以有必要注意其在肠外营养溶液中的存在。
