Hartmann V, Keipert S
Institute of Pharmacy, Humboldt-University, Berlin, Germany.
Pharmazie. 2000 Jun;55(6):440-3.
The influence of artificial tear fluid (AT) on ionic and nonionic ophthalmic polymer excipients was rheologically established. In usual concentrations polyvinylalcohol, polyvinylpyrrolidone, dextran, hydroxypropylmethylcellulose, hydroxyethylcellulose and methylcellulose did not show any changes. In contrast, solutions of polyacrylic acid, sodium hyaluronate (S-Hya), sodium alginate (S-Alg) and chitosan decrease the apparent viscosity in contact with AT, while gellan solution increases the viscosity and shows thixotropy. The adhesion of selected polymers (polysaccharides) on mucin was evaluated using a rheological method and resulted in the order S-Hya > Gellan > S-Alg > dextran. Miosis testing of Gellan containing pilocarpine HCl formulations in rabbits shows a possible reduction of drug concentration from 2% to 0.5% obtaining the same bioavailability.
通过流变学方法确定了人工泪液（AT）对离子型和非离子型眼科聚合物辅料的影响。在常规浓度下，聚乙烯醇、聚乙烯吡咯烷酮、右旋糖酐、羟丙基甲基纤维素、羟乙基纤维素和甲基纤维素均未显示出任何变化。相比之下，聚丙烯酸、透明质酸钠（S-Hya）、海藻酸钠（S-Alg）和壳聚糖溶液在与AT接触时会降低表观粘度，而结冷胶溶液则会增加粘度并表现出触变性。使用流变学方法评估了所选聚合物（多糖）对粘蛋白的粘附性，结果顺序为S-Hya＞结冷胶＞S-Alg＞右旋糖酐。对含结冷胶的盐酸毛果芸香碱兔用制剂进行的缩瞳试验表明，药物浓度可能从2%降至0.5%，但生物利用度相同。
