ABSTRACT
This study employed Box-Behnken design combined with flux attenuation to explore the nanofiltration conditions for separation of alcohol precipitation liquid during the preparation of Reduning Injection and discussed the applicability of nanofiltration in the separation of the liquid with high-concentration ethanol. The effects of nanofiltration molecular weight cut-off(MWCO) and pH on the rejection of chlorogenic acid, 3,5-dicaffeoylquinic acid, and 4,5-dicaffeoylquinic acid were consistent with the principles of pore size sieving and charge effect, respectively. The rejection of the three phenolic acids was reduced by concentration polarization effect caused by trans-membrane pressure(TMP). The swelling of membrane surface decreased the pore size and membrane flux for effective separation. Chlorogenic acid and 4,5-dicaffeoylquinic acid were more sensitive to pH and ethanol concentration than 3,5-dicaffeoylquinic acid. A certain correlation existed between the compound structure and the separation factors of nanofiltration, and the separation rules were associated with the comprehensive effect of charge effect, pore size sieving, concentration polarization, steric hindrance and so on.
Subject(s)
Chlorogenic Acid , Drugs, Chinese Herbal/chemistry , Ethanol , InjectionsABSTRACT
Based on the charge repulsion and solution-diffusion effect in nanofiltration separation, the correlation among mass transfer behavior, solution environment and molecular structure of three typical alkaloids from medicine was analyzed by nanofiltration mass mathematical model. The experiment revealed a linear relationship between ln[(1-Ro)·Jv/Ro] and Jv, and the regression coefficients were all greater than 0.9. Compared with the ultrafiltration separation behavior conforming to molecular sieve, the mass transfer coefficient of three alkaloids under different pH was pH 3.00 < pH 7.00 < pH 10.00. As the pH changed, the state of alkaloid transit from ionic state to a free state, the alkaloid could easily approach the membrane surface and pass through the nanofiltration membrane with charge repulsion and solution-diffusion effects, and the results were verified by the membrane adsorption tendency. The nanofiltration mass transfer of alkaloids is related to the state and molecular weight. In the ionic state, the charge effect produces separation behavior, and the molecular state is related to the molecular weight. The separation mechanism of nanofiltration for alkaloids was clarified further by analyzing the correlation of nanofiltration mass transfer behavior and molecular structure. The results of nanofiltration technology provide references for separation of alkaloids at room temperature with fast separation and low energy consumption.
ABSTRACT
The paper reviews the speciation, process in vivo and biological effects of inorganic elements in Chinese medicine (CM) in the aspect of biopharmaceutics. We also summarize some factors influenced the biopharmceutical characteristics of drugs, including physical and chemical properties, formulation development, body's biological states and different actions. It is significant to safety, rationality of using of CM and modernization, internationalization of CM.