Chlorpropamide

The polyclonal anti-albumin antibodies (goat, fractionated human antiserum, product A1151), Protein G-Sepharose 4B fast flow (recombinant protein expressed in E. coli), immunoglobulin G (goat, ≥ 95% pure) and HSA (essentially fatty acid free, ≥ 96%) were purchased from Sigma-Aldrich (St. Louis, MO, USA). The racemic warfarin (≥ 98%), acetohexamide (99%), gliclazide (≥ 98%), glipizide (˃ 96%), glibenclamide (≥ 99%), and tolbutamide (99.8%) were also acquired from Sigma-Aldrich. The chlorpropamide (≥ 99%) and tolazamide (≥ 99%) were purchased from Santa Cruz Biotechnology (Dallas, TX, USA). The Nucleosil Si-300 and Si-1000 silica (7 μm, particle diameter; pore size, 300 or 1000 Å, respectively) were acquired from Macherey-Nagel (Duren, Germany). All buffers and aqueous solutions were prepared using water from a Milli-Q Advantage 10 A Water system and were filtered using 0.2 μm nylon membranes (EMD Millipore Corporation, Billerica, MA, USA).

The R-warfarin (≥ 97% pure), L-tryptophan (≥ 98%), HSA (product A1887, from human serum, essentially fatty acid free, ≥ 96%), and D-(+)-glucose (99.5%) and were from Sigma-Aldrich (St. Louis, MO, USA). The chlorpropamide (≥ 99%) was purchased from Santa Cruz Biotechnology (Dallas, TX, USA). The Nucleosil Si-300 (pore size, 300 Å; particle size, 7 μm) was acquired from Macherey-Nagel (Duren, Germany). The fructosamine assay was carried out using a kit from Diazyme Laboratories (San Diego, CA, USA). The bicinchoninic acid (BCA) protein assay reagents were acquired from Pierce (Rockford, IL, USA). Water that had been purified by a Milli-Q-Advantage A 10 system (EMD Millipore, Billerica, MA, USA) was used to make all the aqueous solutions and mobile phases that were utilized in this research. These solutions were filtered by passing them through 0.20 μm GNWP nylon membranes from Fisher Scientific (Pittsburgh, PA, USA).