Automated techniques in pKa determination: Low, medium and high-throughput screening methods.

Drug discovery programs that generate hundreds of new molecular entities need efficient methodologies for physicochemical profiling. Several high-throughput methods for pKa screening have been developed in the last 15 years to determine this key physicochemical parameter. Separation techniques such as HPLC-MS or capillary electrophoresis are particularly well-suited due to their high throughput and capacity to deal with impure or complex samples. In addition, potentiometric and (mostly) UV-metric-based methods (plate-based and automated systems), find their place as very precise methodologies for pKa determination despite of somewhat lower throughput. Finally, pKa prediction software packages are useful estimator tools but, to date, they cannot replace experimental measurements when accurate pKa values are required.