T. Sugiyama et al., Selection of mobile phase in high-performance liquid chromatographic determination for medicines, BIOL PHAR B, 23(3), 2000, pp. 274-278
A convenient method was developed to select mobile phase to separate drugs
commonly used in clinical therapy using high-performance liquid chromatogra
phy (HPLC). The separation conditions determined by this method were simila
r for each compound. Two kinds of mobile phase, a mixture of acetonitrile-p
hosphate buffers, pH 4.2 and 2.5, was used and the composition of mobile ph
ase used for a drug in HPLC analysis was systematically determined as follo
ws: (1) the retention time of a drug was measured under the gradient condit
ion, (2) this retention time value was applied to the regression equation w
hich was determined from the retention time values of p-hydroxybenzoate der
ivatives under the gradient condition and the concentration of acetonitrile
in mobile phase, giving about 5 min of retention time, (3) percentage of a
cetonitrile in the isocratic condition was calculated from this regression
equation and a target drug was eluted with the mobile phase consisting: of
the calculated concentration of acetonitrile. According to the proposed met
hod, the composition of mobile phase, with which retention time value was b
etween 4 to 8 min in the isocratic condition, was examined for 75 drugs cli
nically used. Seventy-two of the 75 drugs were analyzed well in the mobile
phase, their composition was calculated by the regression equation, and the
peak shape of each compound was observed to be sharp. Using this method, t
he time required for not only the setting of HPLC conditions but also the a
nalysis will be shortened.