Effect of acidity on the enantiomeric resolution of thyroxine and tocainide by HPLC on a (+) - (18-crown-6) -2,3,11,12-tetracarboxylic acid column
Aboul-Enein, H.Y.; Ali, I.; Hyun, M.H.; Cho, Y.J.; Jin, J.S.
Journal of Biochemical and Biophysical Methods 54(1-3): 407-413
Enantiomeric resolution of thyroxine and tocainide was achieved on a (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid column. The mobile phases were methanol/water (4:1, v/v) and methanol/water containing 5 mM sulfuric acid (4:1, v/v) for tocainide and thyroxine respectively. The flow rate was 0.5 ml/min. The effect of the acidity on the chiral resolution of these drugs was studied. Detection was at 220 nm for both drugs. The values of alpha and Rs were 2.08-3.11 and 1.00-2.60, respectively, for thyroxine while the values of alpha and Rs were 1.13-1.26 and 0.10-1.30, respectively, for tocainide.