Nonlinear Mathematical Model of Preparative Chromatography

초록

Enantiomers have the same physical properties without optical property, and exhibited different activity in human body. One of enantiomer pair has pharmaceutical activity, and the other shows no pharmaceutical activity or even seriousness side effect or interfered with pharmaceutical activity. Because of difficult synthesis, separation by liquid chromatography with CSP(Chiral stationary phase) has been widely used. In this study, the separation condition for racemic bupivacaine was investigated by mathematical model with competitive Langmuir isotherm to find the optimum feed condition, injection volume and injection concentration. The parameters of competitive Langmuir isotherm were assumed and fitted to the experimental data by solving the mathematical adsorption equations with commercially available gPROMS. For each racemic compound, mass transfer coefficients k were obtained by parameter estimation and maximum likelihood method. The agreement of elution profiles between the experimental data and the calculated values was fairly good. In order to find the optimum separation condition, simulations were carried out to determine the feed conditions such as concentration and injection volume. It was experimentally confirmed that for the feed conditions to separate preparatively racemic bupivacaine, injection volumes were 0.05 ml at 2.0 mg/ml of the concentration of racemic mixture and 0.01ml at 20 mg/ml.