Pharmaceutical compounds ionizable functionalities

Also, discussions with the early-phase drug discovery and/or preformulation groups may provide this information because they may have already ascertained the pA of the molecules by titration or other experimental methods (nlON, etc). Table 8-3 shows some of the more common ionizable functionalities present in pharmaceutical compounds. 

The majority of pharmaceutical compounds are either acidic or basic and are therefore ionizable. Other physicochemical properties, such as lipophilicity and solubility, are p Ta dependent therefore, pATa is one of the fundamental parameters of a drug molecule. The pATa determination of acids and bases by CE is based on measuring the electrophoretic mobility of charged species associated with the acid-base equilibria as a function of pH. The detailed theory of pATa and log Pow measurements is beyond the scope of this chapter and readers are referred to a review by Jia [221], which describes in more detail the theoretical aspects of physicochemical profiling by CE methods including FSCE, NACE, MEKC, and MEEKC. 

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