Equilibrium dialysis, ultrafiltration, and ultracentrifugation compared for determining the plasma-protein-binding characteristics of valproic acid

• Published in: Clinical chemistry (Baltimore, Md.) Vol. 31; no. 1; pp. 60 - 64
• Main Authors: BARRE, J, CHAMOUARD, J. M, HOUIN, G, TILLEMENT, J. P
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for Clinical Chemistry 1985
• Subjects: Anticonvulsants. Antiepileptics. Antiparkinson agents; Biological and medical sciences; Blood Proteins - metabolism; Chromatography, Gas; Dialysis - methods; Fatty Acids, Nonesterified - blood; Humans; Medical sciences; Neuropharmacology; Pharmacology. Drug treatments; Protein Binding; Serum Albumin - metabolism; Ultracentrifugation; Ultrafiltration; Valproic Acid - blood; Biological fixation; Anticonvulsant; Serum protein; Equilibrium dialysis
• ISSN: 0009-9147; 1530-8561
• DOI: 10.1093/clinchem/31.1.60

Equilibrium dialysis, ultrafiltration, and ultracentrifugation were compared to determine their reliability and applicability in the study of binding of an anticonvulsant drug, valproic acid, by plasma proteins. We studied drug binding with pooled serum and with solutions of human serum albumin at physiological concentrations. We compared binding characteristics such as number of binding sites, affinity constants, and percent of binding as measured by each method in the therapeutic range for valproic acid. Results by ultracentrifugation differed from those by equilibrium dialysis and ultrafiltration, which agreed reasonably well with each other.