AB-8大孔吸附树脂分离纯化淫羊藿中总黄酮的研究

目的:研究 AB-8大孔吸附树脂分离纯化淫羊藿总黄酮的工艺参数,为分离淫羊藿总黄酮提供最佳吸附洗脱条件。方法:以总黄酮吸附量、醇洗物总黄酮含量、总黄酮回收率为考察指标,考察大孔吸附树脂分离纯化淫羊藿总黄酮的动态吸附洗脱条件。结果:淫羊藿提取物上样浓度为30 mg·ml~-1,药液的 pH 调节为5～6时,最大上样量为250 ml,以2ml·min~(-1)流速吸附,洗脱时采用70%乙醇为洗脱剂,洗脱剂用量为6倍量树脂体积,以2ml·min~(-1)的流速进行洗脱,树脂可重复使用3次为最佳工艺条件。结论:在上述条件下,用 AB-8大孔吸附树脂吸附分离淫羊藿总黄酮,乙醇洗脱物中总黄酮含量达47%以上,总黄酮解析率达86%以上,总黄酮纯度80%以上。     

大孔吸附树脂对淫羊藿总黄酮的吸附性能研究

目的研究不同大孔树脂对淫羊藿总黄酮及淫羊藿苷的吸附及解吸附性能,为分离淫羊藿总黄酮提供树脂选择的依据.方法选择11种常用大孔吸附树脂,以淫羊藿总黄酮和淫羊藿苷为指标,考察不同大孔树脂对两成分的比吸附量和解吸率.同时考察了11种大孔树脂的静态吸附动力学行为.结果对淫羊藿总黄酮比吸附量超过100 mg·g-1的树脂有HPD-300、HPD-400、HPD-500、HPD-600、S-8、AB-8;解吸率超过95%的有D101、HPD-600、AB-8、HPD-400、HPD-500、D201;HPD-600、HPD-500和AB-8为淫羊藿总黄酮快速吸附树脂.结论不同树脂对淫羊藿总黄酮的吸附量、解吸率和速度有很大差异,综合各项试验结果,HPD-600、HPD-500、AB-8为分离淫羊藿总黄酮的最佳吸附树脂.     

淫羊藿总黄酮吸附洗脱工艺的研究

目的　研究淫羊藿总黄酮在吸附树脂上吸附洗脱过程中的工艺特性 ,为生产工艺优化设计提供参考依据。方法　在吸附洗脱过程中 ,分段收集样品 ,用分光光度法测定淫羊藿总黄酮含量。按照测定的数据 ,绘制泄漏曲线图和洗脱曲线图。结果　在吸附过程中 ,树脂吸附淫羊藿总黄酮的吸附终点为 2 3.98mg·ml-1;在洗脱过程中 ,10 0ml洗脱液可集中 89.90 %的淫羊藿总黄酮。结论　利用以上方法和数据 ,可用于生产工艺的优化设计。     

大孔吸附树脂分离纯化淫羊藿EF5黄酮

目的：采用HPLC法和UV法监测AB-8大孔吸附树脂分离纯化以淫羊藿苷、朝藿定A、朝藿定B、朝藿定C和宝藿苷I这五种黄酮为主要成分的淫羊藿EF5黄酮并筛选出最佳分离纯化工艺参数。方法：采用UV法,以淫羊藿总黄酮洗脱率为指标,考察树脂对淫羊藿总黄酮的吸附容量、解吸附率、吸附动力学,以确定树脂分离纯化淫羊藿EF5黄酮的最佳吸附性能;采用HPLC法,以淫羊藿EF5黄酮中五种黄酮单体的洗脱率为指标,考察洗脱液浓度和洗脱液用量等参数,确定淫羊藿EF5黄酮的最佳洗脱参数。结果：AB-8大孔吸附树脂对淫羊藿总黄酮的吸附容量以湿树脂计为（58.37±2.36）mg·g-1,解吸附率为（86.77±2.32）%,最佳吸附时间为180min,最佳洗脱液为60%乙醇,最佳洗脱液用量为5BV,纯化后真空干燥所得棕褐色淫羊藿EF5黄酮粉末中朝藿定A、朝藿定B、朝藿定C、淫羊藿苷和宝藿苷I的含量分别为3.51%、4.87%、1.22%、33.05%、1.36%,淫羊藿EF5黄酮纯度为44%。结论：AB-8大孔吸附树脂分离纯化得到的淫羊藿EF5黄酮的纯度较高,适合工业生产。     

大孔吸附树脂动态纯化葛根藤总黄酮的研究

目的研究大孔树脂动态纯化葛根藤总黄酮的最佳工艺参数。方法采用动态吸附、分离的方法,以总黄酮含量为指标进行考察。结果 D-101大孔吸附树脂静态吸附葛根藤总黄酮的最大吸附量为40.25mg·mL-1;树脂的静置时间为12h;D-101树脂最佳上样浓度为38.00mg·mL-1、70%乙醇为最佳洗脱剂;3mL·min-1做为洗脱剂的洗脱流速为最佳洗脱流速。结论经过工艺验证,在这些参数条件下,分离、纯化葛根藤总黄酮具有良好的重现性。     

大孔吸附树脂对山茱萸总黄酮的分离纯化研究

目的:研究并优化大孔吸附树脂分离纯化山茱萸总黄酮.方法:先以总黄酮含量为考察指标,从3种不同型号的树脂中筛选出分离纯化山茱萸总黄酮的最佳树脂,再对最佳树脂吸附工艺参数进行全面优化.结果:HPD-600型大孔吸附树脂对山茱萸总黄酮的吸附与解析性能较好,确定最佳洗脱条件为50％乙醇洗脱,溶剂用量5 BV.结论:HPD-600型大孔吸附树脂可有效地分离纯化山茱萸总黄酮.     

大孔树脂纯化莲房总黄酮的工艺研究

目的:研究莲房总黄酮的大孔树脂纯化工艺。方法:以莲房总黄酮的吸附率和解析率为指标,通过静态吸附-解吸试验筛选出最优大孔树脂型号;以总黄酮吸附率等为指标,采用单因素试验考察上样液总黄酮质量浓度、吸附时间、吸附流速、上样量、水洗脱用量、洗脱剂体积分数及其用量等因素对莲房总黄酮纯化工艺的影响,并进行验证试验。结果:10种树脂型号中,以HPD-400型大孔树脂对莲房总黄酮的吸附和解吸效果最优;优选的分离纯化条件为上样液总黄酮质量浓度7.00 mg/ml,吸附时间3 h,吸附流速3倍柱体积(BV)/h,上样量8 BV,水洗脱用量6 BV,50%乙醇洗脱用量4 BV;验证试验显示,纯化后莲房总黄酮的质量分数分别为63.88%、62.50%和63.44%(RSD=1.11%,n=3)。结论:HPD-400型大孔树脂可用于纯化莲房中的总黄酮,且建立的分离纯化工艺稳定、可行。     

木瓜总黄酮大孔树脂纯化工艺的优选

目的：优选大孔树脂分离木瓜中总黄酮的工艺条件。方法：以木瓜中总黄酮含量为指标,通过单因素试验考察树脂型号、上样液质量浓度、树脂柱径高比、吸附流速、洗脱剂种类及用量、除杂溶媒种类及用量、洗脱流速等工艺参数对纯化工艺的影响。结果：采用D-140型大孔树脂,优选的纯化工艺为上样液质量浓度为0.1 g·ml-1,上样量为2 BV,径高比1∶9,用3 BV水洗除杂,3 BV10%乙醇洗脱,3 BV50%乙醇以2 BV·h-1洗脱,收集50%乙醇洗脱液,总黄酮质量分数达52%。结论：优选的工艺条件可较好的分离、纯化木瓜中总黄酮。     

AB-8大孔吸附树脂纯化葛根总黄酮

目的 研究AB-8大孔吸附树脂分离纯化葛根总黄酮的工艺条件.方法 以葛根素、葛根总黄酮为指标,对上样相对质量浓度、流速、上样量、水洗脱用量、乙醇洗脱浓度、乙醇用量及树脂再生前使用次数进行考察.结果 上样相对质量浓度:0.20 g·mL-1,流速:3 BV.h-1,上样量:2.5 BV,水洗脱用量:2.0 BV,乙醇洗脱浓度:70%,乙醇用量:2.5 BV,树脂再生前可使用3次.总黄酮和葛根素的纯度分别可达65%和27%.结论 AB-8大孔吸附树脂分离纯化葛根总黄酮的工艺条件可用于葛根中总黄酮的精制.     

大孔树脂吸附分离荆芥总黄酮工艺研究

目的 筛选大孔树脂吸附法分离荆芥总黄酮的最佳洗脱工艺条件.方法 采用D-101型大孔树脂对荆芥总黄酮洗脱吸附,观察上样液流速、浓度、洗脱液浓度对荆芥总黄酮含量影响.结果 实验结果表明,D-101型大孔树脂最佳洗脱工艺参数为上样药液流速3 ml/min,浓度10 mg/ml,洗脱液乙醇浓度70%.结论 D-101型大孔树脂洗脱条件可行方便,适合于荆芥总黄酮分离工艺.     

Absorption from the vagina

Methods and results are reviewed of research on the permeability of the vagina to a wide variety of compounds including steroids, prostaglandins (PGs), antimicrobials, proteins, antigens, and hormones, nonoxynol-9, methadone, and inorganic compounds. Although the literature indicates that the vagina is capable of absorbing a wide variety of organic and inorganic compounds, quantitative data on the extent of absorption are often lacking. Most steroids were readily absorbed and their bioavailability after intravaginal instillation was greater than after oral administration because of a reduced first-pass effect. Natural and synthetic PGs were absorbed; the extent of absorption ranged from 10-43% of the dose. Penicillin and sulfanilamide exhibited extremely variable absorption from the vagina. In most women neither econazole, miconazole, nor clotrimazole were effectively absorbed. In 1943 it was demonstrated that proteins could be absorbed from the vagina. Data on human absorption of nonoxynol-9 are indirect but are consistent with absorption. Methadone, povidone-iodine, and potassium permanganate have also been shown to be absorbed through the vagina. The stage of the reproductive cycle may alter the extent of vaginal absorption, but this has been clearly demonstrated for only 1 substance in the rat.     

Absorption Enhancing Effect of Labrasol on the Intestinal Absorption of Insulin in Rats

The oral absorption enhancing effect of Labrasol? has been studied in rats using insulin as a model peptide/protein drug. Insulin solution was prepared by dissolving insulin in pH 7.4 buffer followed by the addition of Labrasol. The insulin concentration was 50.0 IU/ml. The test insulin/Labrasol solution was administered to the jejunum, ileum and ascending colon of rats at 10.0 IU/kg. After administration, blood samples were collected for 5 h and serum glucose levels and insulin levels were measured. In another group of rats, insulin solution was injected intravenously at 1.0 IU/kg, and both serum glucose and insulin levels were measured. The pharmacological availability of insulin from Labrasol solution was found to be 3.9, 8.9 and 9.1% following jejunal, ileal and colonic administrations, respectively, by comparing the serum glucose level vs. time profiles obtained after intestinal and i.v. administrations. By comparing the serum insulin levels vs. time profiles, the bioavailability of insulin was found to be 0.25 and 0.20% for intra-ileum and colonic administrations, respectively. The hypoglycemic effect of insulin after intra-ileum administration showed a dose-dependency in the insulin dose range from 10.0 to 1.0 IU/kg. These results suggest the absorption enhancing effect of Labrasol on the intestinal absorption of insulin in rats.     

Absorption enhancers

Many current therapeutic drugs, e.g., antibiotics and peptide drugs, are impermeable to outer tissue barriers. Drug delivery of impermeable drugs through such barriers is currently one of the major interests in pharmaceutical research. New classes of absorption enhancers provide rapid absorption in the gastrointestinal tract or skin, with no side effects. This review covers the history of enhancer research, an overview of a variety of absorption enhancers, the nature of enhancing action, and site specificity. The final section focuses on the mechanisms of enhancer action which transiently abolishes or reverses barrier resistance, from the viewpoints of the lipid bilayer barrier containing SH proteins, as well as transcellular/paracellular pathways. Fully understanding these mechanisms is of importance for therapeutic applications.     

Absorption of drugs by the lung

1 Ten patients undergoing diagnostic bronchoscopy had radioisotopically labelled drugs put directly into their bronchi; two received sodium cromoglycate, two salbutamol, three salmefamol and three rimiterol.

2 All four drugs were rapidly absorbed but higher peak plasma levels per unit dose were seen with sodium cromoglycate and salbutamol than with the other two drugs.

3 It is suggested that the lung metabolizes salmefamol and rimiterol but does not metabolize salbutamol or sodium cromoglycate.

     

Multiple Transport Mechanisms Involved in the Intestinal Absorption of Metformin: Impact on the Nonlinear Absorption Kinetics

The aim of this study was to investigate the contributions of multiple transport mechanisms to the intestinal absorption of metformin, focusing on OCT3, PMAT, THTR2, SERT and OCTN2. We also assessed the impact of these transporters on the nonlinear absorption of metformin. Uptake studies with MDCKII cells expressing OCT3, PMAT, THTR2 or SERT confirmed that metformin is a substrate of these transporters. Decynium22 strongly inhibited metformin uptake mediated by all the transporters. 7-Cyclopentyl inhibited OCT3- and THTR2-mediated uptake of metformin. AG835, thiamine and paroxetine specifically inhibited PMAT-, THTR2- and SERT-mediated uptake of metformin, respectively. Using these inhibitors, the relative contributions of OCT3, PMAT, THTR2, SERT, OCTN2 and others to the intestinal permeation of metformin across Caco-2 cells were estimated to be 9.77%, 9.68%, 22.2%, 1.52%, 0% and 0.66%, respectively. Concentration-dependent analysis of metformin uptake by Caco-2 cells revealed nonlinear kinetics with the similar K_m(app) value to the value for THTR2. Further in situ absorption study demonstrated that rat intestinal permeability of metformin was significantly decreased in the presence of decynium22, 7-cyclopentyl and thiamine. The present study indicated that THTR2 is the major determinant of the nonlinear absorption of metformin, although multiple transport mechanisms contribute to its intestinal absorption.     

Small Intestinal Absorption of Bropirimine in Rats and Effect of Bile Salt on the Absorption

The intestinal absorption characteristics of a poorly water-soluble drug, bropirimine, were investigated by the in-situ small intestinal loop method using male Sprague-Dawley rats. Bropirimine in solution was well absorbed in the overall small intestine, following first-order kinetics. The rate determining step for the disappearance of bropirimine from the small intestinal loop after dosing in the suspension was the dissolution process from suspension. Bropirimine was solubilized by sodium glycocholate. The disappearance of bropirimine from the small intestinal loop was suppressed by sodium glycocholate contained in the solution, because of the loss of thermodynamic activity of bropirimine after its involvement in the micellar complex, not by the direct effect of bile salt on the permeability of intestinal mucosa. The disappearance of bropirimine was also suppressed by sodium glycocholate contained in the suspension. The suppression by sodium glycocholate seemed to be caused by the greater influence of sodium glycocholate on the thermodynamic activity of bropirimine than on the dissolution from suspension.     

Transport of Drugs Across the Xenopus Pulmonary Membrane and Their Absorption Enhancement by Various Absorption Enhancers

Purpose. The permeability of drugs across the Xenopus pulmonary membrane and the effects of various absorption enhancers on their absorption were examined using an in vitro Ussing chamber technique. Methods. Phenol red and fluorescein isothiocyanate-labeled dextrans (FDs) with different molecular weights were chosen as water-soluble model drugs. Absorption enhancers used in this study were N-lauryl--D-maltopyranoside (LM), linoleic acid-HCO60 mixed micelle (MM), sodium glycocholate (Na-GC), sodium caprate (Na-Cap), sodium salicylate (Na-Sal) and disodium EDTA (EDTA). Results. The permeability of drugs gradually decreased with increasing their molecular weights, and the absorption of phenol red significantly increased by these absorption enhancers. Among these additives, LM, MM and Na-Cap appeared to be more effective for enhancing the permeability of drugs than the others. Furthermore, we plotted the logarithm of apparent permeability coefficient (Papp) of these drugs against the logarithm of their molecular weights. There exists a good correlation between these parameters. We measured transmembrane resistance(Rm) of Xenopus pulmonary membrane during the transport experiment to examine the membrane integrity. The average Rm value was about 700 ·crn², and this value was maintained for 3 hr. Conclusions. This method is useful for estimating the transport characteristics of drugs across the pulmonary membrane.