The ionization of beta-adrenoceptor agonists: a method for unravelling ionization schemes

To investigate the ionization schemes of beta-adrenoceptor agonists, a combined electrochemical/uv-spectrophotometric method with computer-assisted data-analysis was developed, yielding the macroscopic and microscopic ionization constants. From the four species possible, cations and zwitterions were found the main species present at physiological pH, the formation of uncharged molecules and anions being less favourable or apparently negligible.