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Plasma protein binding of basic drugs
Author(s) -
Borgai Olof,
Piafsky Kenneth M.,
Nilsen Odd G.
Publication year - 1977
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1002/cpt1977225part1539
Subject(s) - alprenolol , orosomucoid , imipramine , chemistry , blood proteins , albumin , plasma protein binding , digitoxin , vacutainer , pharmacology , chromatography , glycoprotein , biochemistry , medicine , receptor , digoxin , heart failure , alternative medicine , pathology
The protein binding of a number of basic drugs has been shown to be inhibited when blood is collected in Vacutainer tubes. We found that the plasticizer tris(2‐butoxyethyl) phosphate (TBEP). present in plasma collected in Vacutainers. was a potent inhibitor of alprenolol and imipramine protein binding. Its concentration in the plasma could quantitatively explain the displacement phenomenon. Alprenolol binding to a solution of a physiologic concentration (0.67 gmlL. 0.015 mM) of α 1 ‐acid glycoprotein (orosomucoid) was decreased from 76% to 16% by addition of 10 uglml (0.026 mM) of TBEP. while imipramine binding was decreased from 69% to 13%. Alprenolol and imipramine binding to albumin and lipoproteins was virtually unchanged by TBEP. Due to its selective effect on binding to α 1 ‐acid glycoprotein. TBEP may be a useful tool for studying plasma protein binding of basic drugs.