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Updated: Jun 6, 2026

Evaluation of Drug Sorption to PVC- and Non-PVC-based Tubes in Administration Sets Using a Pump
Published on: March 11, 2017
Evaluation of the relationship between a pharmaceutical compound's distribution coefficient, log D and adsorption
Eugene P Kadar1, Yi Su, Yizhong Zhang
1Pfizer, Inc., Groton, CT 06340, USA. eugene.p.kadar@pfizer.com
Background:
The distribution coefficient, D, is a physicochemical property used to determine the partitioning of compounds between aqueous and hydrophobic media at a given pH.
Results:
A clear relationship was observed between the calculated pH-dependent distribution coefficient of six representative pharmaceutical probe compounds and their propensity to partition between a relatively hydrophobic polypropylene surface and the aqueous matrices, human urine or human cerebrospinal fluid (CSF). Compound log D cut-off values of 1.5 and 3.8 for urine and CSF, respectively, were determined using a threshold of less than 20% adsorption to the polypropylene surface.
Conclusion:
The ability to forecast the adsorption of a given compound to a polypropylene container with urine and CSF offers an effective means for screening potential issues and identifying when additional testing and corrective measures may need to be applied.
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