Ultrafiltration （UF） experiments were subjected to the concentration of Shi- itake polyphenol（SP） with ultrasound （US） enhancement, by which the effects of the main parameters such as ultrasonic power, transmemb...Ultrafiltration （UF） experiments were subjected to the concentration of Shi- itake polyphenol（SP） with ultrasound （US） enhancement, by which the effects of the main parameters such as ultrasonic power, transmembrane pressure, temperature and axial flow-rate on the membrane fluxes were analyzed, and then the SP of the ultrafiltrate after follow-up resin adsorption by HPLC was investigated. The results in- dicated that US could significantly enhance the membrane fluxes. The optimal con- ditions obtained was as follows： 0.60 W/cm2 US power, axial flow-rate of 80 L/h, operation temperature 30 ~C, transmembrane pressure 0.10 MPa. US increased the absorption capacity of the absorbent resin during the following stage. The HPLC analysis also showed that catechins were purified to some extent as the ultrafiltrate was treated by US and macroporous resin, indicating the technology of US en- hancement coupled with UF showed the potential for concentration and purification of SP by absorbent resins.展开更多
Lamotrigine (LTG) is a widely used antiepileptic drug (AED) for the treatment of new-onset, as well as refractory epilepsy. Due to the narrow treatment window and large individual variability in the pharmacokinetics a...Lamotrigine (LTG) is a widely used antiepileptic drug (AED) for the treatment of new-onset, as well as refractory epilepsy. Due to the narrow treatment window and large individual variability in the pharmacokinetics and pharmacodynamics of LTG, therapeutic drug monitoring (TDM) is necessary in clinical practice to guide dose adjustments. Individual differences and drug combinations can also affect protein binding rate, which further affects the unbound concentration of LTG. The unbound fraction is more closely related to adverse reactions and therapeutic efficacy than total concentration. Therefore, it may be more meaningful to determine the unbound LTG concentration in plasma than the total concentration.Unbound LTG in plasma was extracted by ultrafiltration. High-performance liquid chromatography (HPLC) was used to measure unbound LTG concentration. This method was validated by studies of its selectivity, linearity, lower limit of quantification (LLOQ), accuracy, precision, recovery, and stability.The method was validated over a linear range of 0.2 to 10.0 μg·mL–1, and its LLOQ was 0.2 μg·mL–1. The method’s relative standard deviations (RSDs) for intra-day and inter-day precision were less than 15%, and its accuracy (RE) was ±4.69%. The recoveries of unbound LTG at three different concentrations satisfied the requirements for the analysis of biological samples, and no significant degradation of LTG was observed under different storage conditions.A simple HPLC method showed good performance when used to measure unbound LTG concentration. This method might be used to study the relationship between unboundLTG concentrations and its effectiveness according to TDM.展开更多
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(201303080)Hubei Agricultural Science&Technology Innovation Center Project(2014-620-007-001)Natural Science Foundation of Hubei Province of China(2013CFB053)
文摘Ultrafiltration （UF） experiments were subjected to the concentration of Shi- itake polyphenol（SP） with ultrasound （US） enhancement, by which the effects of the main parameters such as ultrasonic power, transmembrane pressure, temperature and axial flow-rate on the membrane fluxes were analyzed, and then the SP of the ultrafiltrate after follow-up resin adsorption by HPLC was investigated. The results in- dicated that US could significantly enhance the membrane fluxes. The optimal con- ditions obtained was as follows： 0.60 W/cm2 US power, axial flow-rate of 80 L/h, operation temperature 30 ~C, transmembrane pressure 0.10 MPa. US increased the absorption capacity of the absorbent resin during the following stage. The HPLC analysis also showed that catechins were purified to some extent as the ultrafiltrate was treated by US and macroporous resin, indicating the technology of US en- hancement coupled with UF showed the potential for concentration and purification of SP by absorbent resins.
基金Liaoning Province Natural Science Foundation of China(Grant No.2013021079)
文摘Lamotrigine (LTG) is a widely used antiepileptic drug (AED) for the treatment of new-onset, as well as refractory epilepsy. Due to the narrow treatment window and large individual variability in the pharmacokinetics and pharmacodynamics of LTG, therapeutic drug monitoring (TDM) is necessary in clinical practice to guide dose adjustments. Individual differences and drug combinations can also affect protein binding rate, which further affects the unbound concentration of LTG. The unbound fraction is more closely related to adverse reactions and therapeutic efficacy than total concentration. Therefore, it may be more meaningful to determine the unbound LTG concentration in plasma than the total concentration.Unbound LTG in plasma was extracted by ultrafiltration. High-performance liquid chromatography (HPLC) was used to measure unbound LTG concentration. This method was validated by studies of its selectivity, linearity, lower limit of quantification (LLOQ), accuracy, precision, recovery, and stability.The method was validated over a linear range of 0.2 to 10.0 μg·mL–1, and its LLOQ was 0.2 μg·mL–1. The method’s relative standard deviations (RSDs) for intra-day and inter-day precision were less than 15%, and its accuracy (RE) was ±4.69%. The recoveries of unbound LTG at three different concentrations satisfied the requirements for the analysis of biological samples, and no significant degradation of LTG was observed under different storage conditions.A simple HPLC method showed good performance when used to measure unbound LTG concentration. This method might be used to study the relationship between unboundLTG concentrations and its effectiveness according to TDM.
