Investigation of metformin hydrochloride-bovine serum albumin interaction by narrow-bore capillary zone electrophoresis.

A narrow-bore capillary (inner diameter = 2 μm) zone electrophoresis method was developed to study the interaction between metformin hydrochloride and bovine serum albumin. Free metformin hydrochloride, free bovine serum albumin, and their complex were completely separated in a volume of tens of picoliters. The association constant ( K a = 1.04 × 10 3 L mol -1 ) and the number of binding sites ( n = 0.9789) were then obtained.