Insight into the chiral recognition of warfarin enantiomers by epichlorhydrin/beta-cyclodextrin polymer-based supports: determination of stoichiometry and stability of warfarin/beta-cyclodextrin polymer complexes.

The complexation of warfarin (W) enantiomers by a hydrosoluble high-molecular-weight beta-cyclodextrin/epichlohydrin polymer (EP/beta-CD polymer) was studied using HPLC with a mobile phase of methanol/0.1 M Na acetate/acetic acid (pH 4) at 22 degrees C. It was found that the complexes (W/beta-CD unit) have a 1:1 stoichiometry.

Study of the retention properties of warfarin enantiomers on a beta-cyclodextrin polymeric support.

High-performance liquid chromatography was used to study the retention properties of (R)- and (S)-warfarins on a silica support coated with a beta-cyclodextrin polymer. The influence of the methanol content of the acetate buffer eluent was investigated at pH 4. The measure of the variations of retention time with temperature enables one to determine the enthalpy and the entropy of adsorption.

Separation procedures used to reveal and follow drug-protein binding.

The review gives a critical evaluation of the different separation procedures used to study drug-protein interactions and describes their various fields of application. For pharmacological studies, the most widely used methods are dialysis and ultrafiltration, because they allow measurements with solutions of high protein concentrations, such as those found in therapeutic conditions. Both techniques use membrane devices, which may induce additional binding effects.

Determination of association constants of beta-cyclodextrin and beta-cyclodextrin-bearing polymers with drugs by high-performance liquid chromatography.

A high-performance liquid chromatographic (HPLC) support was prepared, based on silica beads coated with a beta-cyclodextrin-containing polymer, which allows the elution of solutes in order of their affinity for beta-cyclodextrin. Binding constants were determined from the retention data for drugs eluted with pure buffer on the new support and good agreement was observed with results obtained by the Hummel and Dreyer method, previously used in HPLC studies of drug-protein interactions.

Retention data methods for the determination of drug-protein binding parameters by high-performance liquid chromatography.

The binding to human serum albumin of some drugs (warfarin, furosemide and phenylbutazone) has been studied by high-performance liquid chromatography. Two methods have been used and compared, based on the measurement of the ligand retention volume under different conditions. The obtained total affinities of the drugs for the protein are in accordance with our previous results.