Cawello W, Bonn R
Arzneimittelforschung. 1983;33(4):595-7.
The loss of nitroglycerin (glycerol trinitrate (GTN), Perlinganit) when infused at various rates through polyvinyl chloride (PVC) tubing was measured against time by continuously monitoring the GTN concentrations at the outflow of the tubing using a direct photometric method. The portion of GTN loss depends on the rate of infusion; at flow rates of 3-6 ml/h, GTN losses of up to 60% may be expected. Polyethylene (PE) tubing does not show this reduction in the outflow concentration of GTN. When GTN is infused through PVC tubing, the dosage cannot be controlled and any assessment of pharmacokinetics or absolute bioavailability becomes invalid. This effect of tubing accounts for apparent losses of bioavailability of up to 50%. Other organic nitrates like isosorbide dinitrate are shown to be absorbed into PVC in a similar way. The losses increase with larger liphophilicity of the drug.
通过使用直接光度法连续监测聚氯乙烯（PVC）输液管流出端的硝酸甘油（甘油三硝酸酯（GTN），佩尔林加尼特）浓度，来测定以不同速率通过PVC输液管输注时硝酸甘油随时间的损失情况。硝酸甘油损失的比例取决于输注速率；在3 - 6毫升/小时的流速下，预计硝酸甘油损失高达60%。聚乙烯（PE）输液管不会出现硝酸甘油流出浓度的这种降低情况。当通过PVC输液管输注硝酸甘油时，剂量无法控制，任何药代动力学或绝对生物利用度的评估都变得无效。输液管的这种影响导致生物利用度的明显损失高达50%。其他有机硝酸盐如异山梨醇二硝酸酯也以类似方式被PVC吸收。药物的亲脂性越强，损失越大。
