Aim To investigate the combined effect of hydroxypropyl-β-cyclodextrin （HP-β-CD） and media pH on the solubility of prostaglandin E1 （PGE1） and construct a theoretical equation for the drug solubility as a functi...Aim To investigate the combined effect of hydroxypropyl-β-cyclodextrin （HP-β-CD） and media pH on the solubility of prostaglandin E1 （PGE1） and construct a theoretical equation for the drug solubility as a function of HP-β-CD concentration and media pH. Methods The solubility of PGE1 under different pH conditions was determined. Then, the drug solubility in different concentrations of HP-β-CD acidic or pH neutral solutions was measured, respectively. Finally, a theoretical solubility equation for the drug as a function of HP-β-CD concentration and media pH was deduced and confirmed in experiment. Results PGEs was solubilized by HP-β-CD or by increasing media pH. The drug solubility as a function of HP-β-CD concentration was found to follow the AL-type complexation model in acidic or neutral pH media, suggesting that both the ionized and neutral drugs form 1：1 molecular ratio complexes. Conclusions The solubility of PGE1 may be improved by increasing media pH or by using HP-β-CD as a solubilizer. HP-β-CD and media pH can produce combined effect on the solubility of PGE1. The deduced equation for the drug solubility in this study effectively characterizes the roles of HP-β-CD and media pH in determining total solubility of the drug.展开更多
Dual-point composition control for a high-purity ideal heat integrated distillation column (HIDiC) is addressed in this work. Three measures are suggested and combined for overcoming process inherent nonlinearities:(1...Dual-point composition control for a high-purity ideal heat integrated distillation column (HIDiC) is addressed in this work. Three measures are suggested and combined for overcoming process inherent nonlinearities:(1) variable scaling; (2) multi-model representation of process dynamics and (3) feedforward compensation. These strategies can offer the developed control systems with several distinct advantages: (1) capability of dealing with severe disturbances; (2) tight tuning of controller parameters and (3) high robustness with respect to variation of operating conditions. Simulation results demonstrate the effectiveness of the proposed methodology.展开更多
文摘Aim To investigate the combined effect of hydroxypropyl-β-cyclodextrin （HP-β-CD） and media pH on the solubility of prostaglandin E1 （PGE1） and construct a theoretical equation for the drug solubility as a function of HP-β-CD concentration and media pH. Methods The solubility of PGE1 under different pH conditions was determined. Then, the drug solubility in different concentrations of HP-β-CD acidic or pH neutral solutions was measured, respectively. Finally, a theoretical solubility equation for the drug as a function of HP-β-CD concentration and media pH was deduced and confirmed in experiment. Results PGEs was solubilized by HP-β-CD or by increasing media pH. The drug solubility as a function of HP-β-CD concentration was found to follow the AL-type complexation model in acidic or neutral pH media, suggesting that both the ionized and neutral drugs form 1：1 molecular ratio complexes. Conclusions The solubility of PGE1 may be improved by increasing media pH or by using HP-β-CD as a solubilizer. HP-β-CD and media pH can produce combined effect on the solubility of PGE1. The deduced equation for the drug solubility in this study effectively characterizes the roles of HP-β-CD and media pH in determining total solubility of the drug.
基金Supported by the New-Energy and Industry Technology Development Organization (NEDO) through the Energy Conservation Center of Japan.
文摘Dual-point composition control for a high-purity ideal heat integrated distillation column (HIDiC) is addressed in this work. Three measures are suggested and combined for overcoming process inherent nonlinearities:(1) variable scaling; (2) multi-model representation of process dynamics and (3) feedforward compensation. These strategies can offer the developed control systems with several distinct advantages: (1) capability of dealing with severe disturbances; (2) tight tuning of controller parameters and (3) high robustness with respect to variation of operating conditions. Simulation results demonstrate the effectiveness of the proposed methodology.
