目的:优化超临界流体强化溶液快速分散技术(SEDS)制备冬凌草甲素脂质体口服制剂(ORI-LIP)的工艺,并探讨其与常规脂质体制备技术的优势。方法:以粒径为评价指标,采用正交试验考察压力、温度、进样流速对SEDS制备ORI-LIP的影响。同时,采...目的:优化超临界流体强化溶液快速分散技术(SEDS)制备冬凌草甲素脂质体口服制剂(ORI-LIP)的工艺,并探讨其与常规脂质体制备技术的优势。方法:以粒径为评价指标,采用正交试验考察压力、温度、进样流速对SEDS制备ORI-LIP的影响。同时,采用薄膜分散法和逆向蒸发法制备ORI脂质体,比较3种方法所制脂质体的粒径、包封率、载药量及稳定性(6个月加速试验),并比较ORI原料药与3种脂质体的体外溶出行为的差异。结果:优化后的ORI-LIP SEDS制备工艺条件为温度50℃,压力18MPa,进样流速1 m L/min;与薄膜分散法和逆向蒸发法比较,以SEDS技术制备的脂质体的粒径[(147.4±4.8)nm]更小,包封率(67.8%)、载药量(7.8%)及稳定性(粒径略有增加,包封率仅降低4.4%)都更高。体外溶出试验结果显示,与原料药比较,各脂质体的释药速率缓慢且持久,且累积释放度更高;其中,SEDS技术制备的ORI-LIP在24 h时达到溶出平衡,且累积溶出度最高,达到67.2%。结论:SEDS制备的ORI-LIP粒径小,包封率、载药量较高,稳定性较好,能显著提高药物的体外溶出度;该技术与常规脂质体制备技术相比有一定的优势。展开更多
目的观察超临界流体强化溶液快速分散技术(SEDS)制备三七皂苷脂质体(PNS-Lip)的药剂学特征,并与常规脂质体制备方法进行比较。方法采用超临界流体强化溶液快速分散技术(SEDS)、薄膜分散法(TFD)、逆向蒸发法(RPE)制备PNS-Lip。透射电镜...目的观察超临界流体强化溶液快速分散技术(SEDS)制备三七皂苷脂质体(PNS-Lip)的药剂学特征,并与常规脂质体制备方法进行比较。方法采用超临界流体强化溶液快速分散技术(SEDS)、薄膜分散法(TFD)、逆向蒸发法(RPE)制备PNS-Lip。透射电镜观察不同PNS-Lip外观形态;检测粒径与电位;超滤法测定包封率(EE)和载药量(DL);以药物泄漏率(LR)评价制剂稳定性;进行体外溶出实验检测。结果不同制备方法制得的PNS-Lip呈现出淡蓝色乳光,表面光滑,形态圆整,具有双层膜结构。与PNS-Lip-RPE比较,PNS-Lip-TFD及PNS-Lip-SEDS粒径、多分散系数(PDI)、Zeta电位降低,60、120、180、240、300、360 s LR降低,EE和DL升高(P<0.05,P<0.01);PNS-Lip-SEDS在420s LR降低(P<0.05)。与PNS-Lip-TFD比较,PNS-Lip-SEDS的粒径、PDI及Zeta电位降低,180、240、300、360、420 s LR降低,EE和DL升高(P<0.05,P<0.01)。PNS-Lip-RPE及PNS-Lip-TFD在初始阶段存在突释作用,随后持续缓慢释放;PNS-Lip-SEDS未发生突释现象,缓释作用更加明显,在48 h后达到溶解平衡。结论SEDS作为新型的制粒技术,与常规的脂质体制备方法相比具有一定的优势,该技术在纳米给药系统领域具有广阔的应用前景。展开更多
We read the original article by Nuis, et al. and the reply by Dogan, et al. with great interest. Nuis, et al. examined whether transcatheter aortic valve implantation （TAVI） in patients suffering from severe aortic ...We read the original article by Nuis, et al. and the reply by Dogan, et al. with great interest. Nuis, et al. examined whether transcatheter aortic valve implantation （TAVI） in patients suffering from severe aortic stenosis led to changes in corrected QT dispersion （cQTD）, previously used to predict arrhythmic risk. Dogan, et al. proposed that a different marker, transmural dispersion of repolariza- tion （TDR）, has better accuracy in risk prediction.展开更多
A discrete dislocation plasticity analysis of dispersion strengthening in oxide dispersion strengthened(ODS) steels was described. Parametric dislocation dynamics(PDD) simulation of the interaction between an edge dis...A discrete dislocation plasticity analysis of dispersion strengthening in oxide dispersion strengthened(ODS) steels was described. Parametric dislocation dynamics(PDD) simulation of the interaction between an edge dislocation and randomly distributed spherical dispersoids(Y2O3) in bcc iron was performed for measuring the influence of the dispersoid distribution on the critical resolved shear stress(CRSS). The dispersoid distribution was made using a method mimicking the Ostwald growth mechanism. Then, an edge dislocation was introduced, and was moved under a constant shear stress condition. The CRSS was extracted from the result of dislocation velocity under constant shear stress using the mobility(linear) relationship between the shear stress and the dislocation velocity. The results suggest that the dispersoid distribution gives a significant influence to the CRSS, and the influence of dislocation dipole, which forms just before finishing up the Orowan looping mechanism, is substantial in determining the CRSS, especially for the interaction with small dispersoids. Therefore, the well-known Orowan equation for determining the CRSS cannot give an accurate estimation, because the influence of the dislocation dipole in the process of the Orowan looping mechanism is not accounted for in the equation.展开更多
文摘目的:优化超临界流体强化溶液快速分散技术(SEDS)制备冬凌草甲素脂质体口服制剂(ORI-LIP)的工艺,并探讨其与常规脂质体制备技术的优势。方法:以粒径为评价指标,采用正交试验考察压力、温度、进样流速对SEDS制备ORI-LIP的影响。同时,采用薄膜分散法和逆向蒸发法制备ORI脂质体,比较3种方法所制脂质体的粒径、包封率、载药量及稳定性(6个月加速试验),并比较ORI原料药与3种脂质体的体外溶出行为的差异。结果:优化后的ORI-LIP SEDS制备工艺条件为温度50℃,压力18MPa,进样流速1 m L/min;与薄膜分散法和逆向蒸发法比较,以SEDS技术制备的脂质体的粒径[(147.4±4.8)nm]更小,包封率(67.8%)、载药量(7.8%)及稳定性(粒径略有增加,包封率仅降低4.4%)都更高。体外溶出试验结果显示,与原料药比较,各脂质体的释药速率缓慢且持久,且累积释放度更高;其中,SEDS技术制备的ORI-LIP在24 h时达到溶出平衡,且累积溶出度最高,达到67.2%。结论:SEDS制备的ORI-LIP粒径小,包封率、载药量较高,稳定性较好,能显著提高药物的体外溶出度;该技术与常规脂质体制备技术相比有一定的优势。
文摘目的观察超临界流体强化溶液快速分散技术(SEDS)制备三七皂苷脂质体(PNS-Lip)的药剂学特征,并与常规脂质体制备方法进行比较。方法采用超临界流体强化溶液快速分散技术(SEDS)、薄膜分散法(TFD)、逆向蒸发法(RPE)制备PNS-Lip。透射电镜观察不同PNS-Lip外观形态;检测粒径与电位;超滤法测定包封率(EE)和载药量(DL);以药物泄漏率(LR)评价制剂稳定性;进行体外溶出实验检测。结果不同制备方法制得的PNS-Lip呈现出淡蓝色乳光,表面光滑,形态圆整,具有双层膜结构。与PNS-Lip-RPE比较,PNS-Lip-TFD及PNS-Lip-SEDS粒径、多分散系数(PDI)、Zeta电位降低,60、120、180、240、300、360 s LR降低,EE和DL升高(P<0.05,P<0.01);PNS-Lip-SEDS在420s LR降低(P<0.05)。与PNS-Lip-TFD比较,PNS-Lip-SEDS的粒径、PDI及Zeta电位降低,180、240、300、360、420 s LR降低,EE和DL升高(P<0.05,P<0.01)。PNS-Lip-RPE及PNS-Lip-TFD在初始阶段存在突释作用,随后持续缓慢释放;PNS-Lip-SEDS未发生突释现象,缓释作用更加明显,在48 h后达到溶解平衡。结论SEDS作为新型的制粒技术,与常规的脂质体制备方法相比具有一定的优势,该技术在纳米给药系统领域具有广阔的应用前景。
文摘We read the original article by Nuis, et al. and the reply by Dogan, et al. with great interest. Nuis, et al. examined whether transcatheter aortic valve implantation （TAVI） in patients suffering from severe aortic stenosis led to changes in corrected QT dispersion （cQTD）, previously used to predict arrhythmic risk. Dogan, et al. proposed that a different marker, transmural dispersion of repolariza- tion （TDR）, has better accuracy in risk prediction.
文摘A discrete dislocation plasticity analysis of dispersion strengthening in oxide dispersion strengthened(ODS) steels was described. Parametric dislocation dynamics(PDD) simulation of the interaction between an edge dislocation and randomly distributed spherical dispersoids(Y2O3) in bcc iron was performed for measuring the influence of the dispersoid distribution on the critical resolved shear stress(CRSS). The dispersoid distribution was made using a method mimicking the Ostwald growth mechanism. Then, an edge dislocation was introduced, and was moved under a constant shear stress condition. The CRSS was extracted from the result of dislocation velocity under constant shear stress using the mobility(linear) relationship between the shear stress and the dislocation velocity. The results suggest that the dispersoid distribution gives a significant influence to the CRSS, and the influence of dislocation dipole, which forms just before finishing up the Orowan looping mechanism, is substantial in determining the CRSS, especially for the interaction with small dispersoids. Therefore, the well-known Orowan equation for determining the CRSS cannot give an accurate estimation, because the influence of the dislocation dipole in the process of the Orowan looping mechanism is not accounted for in the equation.
