葛根大豆甙元与poloxamer共沉淀物的研究

应用溶剂-熔融法将葛根大豆甙元与载体poloxamer制成不同比例的共沉淀物以提高药物的溶出速度。采用差热分析和热台显微镜技术,测得其组成中含药物2.1%时共熔点为44℃,偏光显微镜观察及X射线图谱表明,1.7%以下的共沉淀物为固溶体,2.1%的共沉淀物中,甙元以最微细的晶体分散于载体中,在人工肠液中溶出速度和平衡溶解度测定显示,溶出度(T_(60))1%为2min,2.1%为4min,甙元约为60min,相应的平衡溶解度分别为52.47、35.30和4.37μg/ml(37±0.5℃)。     

改善葛根黄豆甙元体外溶出

目的 :提高葛根黄豆甙元水溶性及溶出度 ,改善其生物利用度。方法 :采用研磨法减小药物粒径 ,制成固体分散物及 β 环糊精包合法。 结果 :溶解度试验结果为甙元 3 1 4 ,而上述不同改良后的结果为 5 4 2～ 50 0 8之间。 2h溶出度结果 ,甙元片为 8 87% ,而改良后结果在 1 3 67%。结论 :三种方法均不同程度提高该药溶解性及溶出度 ,其中以PVP不同比例固体分散物溶解性及溶出度提高幅度最大。     

葛根中异黄酮含量的薄层光密度法测定

本文报道了葛根中异黄酮成分含量的薄层光密度测定法。用甲苯—甲醇—10%甲酸(7:3:0.02)和乙酸乙酯—甲醇—50%甲酸(8:2:0.2)为展开剂,在硅胶G薄层上分离了大豆甙元、大豆甙、葛根素和大豆甙元-4′,7-二葡萄糖甙,并用CS-910双波长薄层扫描仪进行了定量测定。变异系数为1.5～1.6%,采用本法测定了生药和片剂样品的含量。     

黄豆苷元液体硬胶囊的处方筛选及其 体外溶出度考察

摘要：目的 通过液体硬胶囊技术提高黄豆苷元的体外溶出度。 方法 设计了一系列处方测定黄豆苷元液体硬胶囊的平衡水量;采用紫外分光光度法测定黄豆苷元液体硬胶囊的体外溶出度，筛选出最适宜的PVP K30用量;采用HPLC法测定黄豆苷元液体硬胶囊的含量。 结果 最佳处方的平衡水量为8％，黄豆苷元与PVP K30的最优质量比为1:7 ;黄豆苷元液体硬胶囊的体外溶出度45 min可达到90％以上，含量质量分数为100.03%。结论 通过加入一定量的水使胶囊壳和内容物之间达到水分的平衡，解决了吸水性辅料和硬胶囊壳的相容性问题;制备的黄豆苷元液体硬胶囊有较高的体外溶出度。     

葛根黄豆甙元-PVP分散物的研究

本文采用聚乙烯吡咯烷酮(PVP)为载体,制备了葛根黄豆甙元固体分散物。经差热分析、X-射线衍射、偏光显微镜观察实验证明黄豆甙元-PVP 1∶9固体分散物为固体溶液或共沉淀物,其胶囊在人工胃液中最高累积释放百分量和人工肠液中平衡溶解度均是普通胶囊的8倍左右。     

大豆苷元固体自乳化制剂的处方优化和制备

目的:优化大豆苷元固体自乳化制剂的处方。方法:通过处方配伍试验和伪三元相图的绘制,以乳化程度和乳化时间为指标,确定乳化剂、油相和助乳化剂种类;采用星点设计-效应面法,以平均粒径与Zeta电位为指标,优选最佳自乳化处方;以β-环糊精为吸附材料,制备大豆苷元固体自乳化制剂,并采用差示扫描量热(DSC)分析和X-射线衍射鉴别药物在载体中的存在状态。结果:优化后的处方为大豆苷元:吐温80:二乙二醇单乙基醚:油酸乙酯:β-环糊精=9.4:54.2:20.1:25.7:437.6。DSC和X-射线分析结果显示,药物在载体中以无定形或分子形式存在。大豆苷元固体自乳化制剂45min溶出度达85%以上。结论:固体自乳化释药系统能够提高大豆苷元的体外溶出度。     

大豆苷元固体分散体胶囊的溶出度测定

目的:建立以高效液相色谱法测定大豆苷元固体分散体胶囊溶出度的方法。方法:色谱柱为HypersilC18,流动相为水-乙腈(70∶30),流速为1.0mL·min-1,检测波长为249nm,柱温为30℃;并按《中国药典》转篮法测定其溶出度。结果:大豆苷元检测浓度的线性范围为1.0～10.0μg.mL-1(r=0.9998);平均回收率为100.12%,RSD=1.65%;3批样品45min溶出度均在90.0%以上。结论:本方法灵敏、准确、专属性强,可用于该制剂的溶出度测定。     

葛根中总黄酮的导数脉冲极谱测定

葛根为豆科植物,是中医常用的祛风解表药,多年来临床试验证明葛根制剂对伴有颈项强痛、头痛、头晕的高血压病、心绞痛、早期耳蜗性聋、偏头痛等病症均有较好的疗效。通过化学、药理和临床试验证明,葛根的有效成分是葛根素(puerarin)、大豆甙(daidzin)和大豆甙元(daidzein)等异黄酮类化合物,其结构如下:     

共研磨法改善水飞蓟素固体分散体的溶出度

目的:通过共研磨技术改善水飞蓟素固体分散体的体外溶出度。方法:设计单因素试验考察溶出度的影响因素,如共研磨载体材料的种类及与共研磨药物的比例,研磨的时间等因素。结果:以甘露醇与PVP K30为混合亲水性载体材料,与药物的比例为1∶1∶1,研磨6 h,以pH7.4的磷酸盐缓冲溶液为溶出介质。结论:共研磨法制备水飞蓟素固体分散体能显著提高药物的体外溶出度,且制备工艺简单易行。     

卡维地洛固体分散体的初步研制

目的:制备卡维地洛固体分散体并考察其体外溶出度。方法:以聚乙二醇(PEG)、聚乙烯吡咯烷酮(PVP)的混合物(2∶1、1∶2)为载体,采用溶剂熔融法和共沉淀法制备载体与药物不同比例的固体分散体并比较其体外溶出度。结果:药物溶出度随载体比例增加而增加;载体与药物比例越小,固体分散体与药物原料粉之间溶出度差异越显著;PEG∶PVP(1∶2)所制分散体体外溶出行为较优,以3、10、30、60min时溶出百分率进行比较,固体分散体是药物原料粉的3～8倍。结论:所制卡维地洛固体分散体能增加药物体外溶出度。     

Formation and characterization of porous indomethacin-PVP coprecipitates prepared using solvent-free supercritical fluid processing

Supercritical carbon dioxide (sc-CO2) was used to prepare coprecipitates of indomethacin (IM) and poly(vinylpyrrolidone) (PVP) with the aim to improve the dissolution rate of IM. The coprecipitates of IM and PVP at various proportions were prepared using a stirred batch reactor containing sc-CO2 as a gas saturated solution (i.e., the compressible CO2 is dissolved in the molten compound). Temperatures between 40 and 90 degrees C and pressure of 150 or 200 bar were employed. The coprecipitates prepared at 75 degrees C and 150 bar were characterized using differential scanning calorimetry (DSC), powder X-ray diffraction (PXD), scanning electron microscopy (SEM), and dissolution testing. The results suggested that IM was totally amorphous at PVP weight fraction of 0.80 and above (indeed, as a molecular composite in which the drug molecules interact with the polymer backbone). As the PVP weight fraction decreased, IM displayed an increasing amount of crystalline material. The SEM photographs of coprecipitates showed a foamed and porous structure. The dissolution rate of IM was increased by incorporation of PVP. IM and PVP at various weight fractions exhibited comparatively higher dissolution rates than that of crystalline IM alone. The sc-CO2 based process produced a solvent free, completely amorphous porous IM solid dispersion with a rapid dissolution rate.     

Dissolution of fludrocortisone from phospholipid coprecipitates.

The physical properties and dissolution behavior of phospholipid coprecipitates of fludrocortisone acetate (FA) prepared from ethyl acetate, as well as the effect of added polymer, have been determined. The fraction dissolved after 90 min and the initial dissolution rate (IDR) of coprecipitates containing dimyristoyl phosphatidylcholine (DMPC) (4:1, w/w; FA:DMPC) were 77% and 3.5-fold greater than for FA at pH 2.0 and 37 degrees C. The mechanisms of dissolution were similar to those previously established for griseofulvin, but no aging occurred over 4 months at room temperature in a desiccator. The addition of 0.01 mol% of dextran (MW = 2 million) or 0.1 mol% of poly(lactic acid) reduced the fraction of FA dissolved in 90 min by 15% and reduced the IDR by 35%. The addition of poly(vinylpyrrolidone) (PVP) resulted in a minimum of dissolution efficiency at 1 mol% of PVP 10 (MW = 10,000) or PVP 24 (MW = 24,000) and at 0.1 mol% PVP 40 (MW = 40,000). Only PVP 24 influenced the melting point and heat of fusion of the coprecipitates (determined by differential thermal analysis). Coprecipitate dissolution was reasonably described by either second-order or Weibull distribution kinetic models. These results support the application of high drug-containing solid dispersions using phospholipids to increase the dissolution behavior of poorly water-soluble drug solvates and the possibility of modifying drug release by the incorporation of small amounts of polymers.     

Interaction between macromolecular adjuvants and drugs. 24. Improvement of the solubility characteristics of benzodiazepine derivatives with polyvinylpyrrolidone

Solubility and dissolution rate of the benzodiazepine derivatives chlordiazepoxide, diazepam, medazepam, nitrazepam and clonazepam has been improved by adding polyvinylpyrrolidone (PVP K 30). Increasing concentrations of the carrier as well as the preparation of coprecipitates usually supported the effect (less physical mixtures). Regarding to the dissolution PVP has a positive effect on the initial phase of dissolution particularly. Under the experimental conditions described an interaction between drugs and carrier was revealed increasing with the concentration of PVP. These interactions were of endothermic character. Connections between dissolution and binding results were evident. Differential thermal analysis and x-ray diffractometric studies probably refer to a partial amorphous form of the drugs, especially in coprecipitates with a higher concentration of PVP.     

In vitro release,rheological, and stability studies of mefenamic acid coprecipitates in topical formulations

A suitable topical formulation of mefenamic acid was developed in order to eliminate the gastrointestinal disorders associated with its oral administration. Drug coprecipitates prepared with different polymers at various drug-to-polymer ratios improved drug solubility and dissolution compared to pure drug and physical mixtures. PVP polymers (ratio 1:4) produced the best results. Aqueous ionic cream, ointments of absorption and water soluble bases and gels of methylcellulose, carboxymethylcellulose sodium, HPMC, Carbopol^® 934 and 940, and Pluronic^® F127 bases containing 1–10% drug as coprecipitates of PVP polymers (1:4) were prepared. The highest drug release was achieved at 1% drug concentration from water soluble base and methylcellulose among cream/ointment and gel bases, respectively. Gels, in general yielded better release than creams/ointments. All tested medicated creams/ointments exhibited plastic flow while all gels conformed to pseudoplasticity. Most of them showed thixotropy, a desired property of topical preparations. Stability studies revealed that HPMC and methylcellulose had the smallest changes in drug content, viscosity, and pH among the formulations. Considering drug release, rheological properties, and stability, methylcellulose gel containing 1% drug as coprecipitates of PVP K90 was the best among the studied formulations, was promising for improving bioavailability of mefenamic acid and can be used in future studies.     

PVP K30对葛根黄豆苷元增溶的研究

研究了葛根黄豆苷元(1)在不同温度、不同浓度的PVP K30—磷酸盐缓冲液中的溶解度，1溶解度随辅料浓度的增大而明显增大。溶解度数据经热力学方法处理，表明这是个自发过程。采用溶剂法，以PVP K30为载体制备1固体分散体，考察固体分散体中1的溶解度和溶出度。与其本身相比，固体分散体中1溶解度显著提高，溶出速度明显增大。     

Studies on hydrophobic drug-soluble carrier coprecitates (II)

In an attempt to elucidate further physicochemical properties of furosemide-PVP coprecipitates, extensive investigations such as TLC, UV, IR, NMR, X-ray diffraction, TGA and DTA studies were carried out for the furosemide test systems. X-ray diffraction studies revealed that the pure furosemide and the furosemide contained within a physical mixture were crystalline in nature. However, there was no crystallinity evident in the 1∶5 furosemide-PVP 40,000 coprecipitate system, even after standing for two years. The various ratio furosemide-PVP 40,000 coprecipitate systems revealed that the coprecipitate containing a greater amount of PVP 40,000 than that of furosemide showed a crystalline state of furosemide and that the minimum amounts of PVP to make amorphous form of furosemide was 1∶1 ratio of furosemide to PVP. From the furosemide-PVP coprecipitate systems with PVP of different molecular weights of 10,000, 40,000, and 360,000, all the 1∶1 ratio coprecipitates did not exhibit any crystallinity of furosemide, whereas all the 2∶1 ratio coprecipitates showed a presence of crystalline furosemide. All the coprecipitated preparations with PEG 4,000 and with PEG 6,000 showed the diffraction peaks indicating the presence of crystalline furosemide. The comparison of infrared spectra of the physical mixture and the coprecipitate showed an interaction such as association between the functional groups of furosemide and PVP in the molecular level, whereas the studies by TLC, UV and NMR showed its dissociation in methanol solution. The weight losses in TGA curves showed all the same patterns. However, a little different transition form in DTA thermograms was shown between the physical mixture and the coprecipitate, indicating the different thermal property.     

Amorphous spray-dried hydroflumethiazide-polyvinylpyrrolidone systems: physiochemical properties

Hydroflumethiazide was spray-dried with polyvinylpyrrolidone (PVP) to produce products containing 0-30% PVP. These systems were amorphous and differed from previously prepared coprecipitates of similar composition. Differential scanning calorimetry (DSC) suggested that at low PVP weight fractions both amorphous drug and an amorphous drug-PVP complex can be present in spray-dried systems. The apparent solubility of hydroflumethiazide in spray-dried products increased with increasing PVP content reaching a plateau value approximately four times that of the pure crystalline drug. The estimated free energy and entropy of the spray-dried drug were greater than that of crystalline drug and also increased with increasing PVP content. Dissolution studies with compressed discs supported the apparent solubility data. The results suggest that amorphous phases having different orders of organization are formed in spray-dried systems with increasing PVP content.     

异黄酮对前列腺癌细胞及PTEN基因的影响

目的 通过大豆异黄酮抑制前列腺癌PC-3和LNCaP细胞生长和相关基因表达的影响，探讨大豆异黄酮类抑制前列腺癌的机制。方法 对染料木黄酮和大豆甙元作用后的雄激素非依赖型前列腺癌(PC-3)、雄激素依赖型前列腺癌LNCaP细胞的存活率、细胞毒作用、细胞周期和PTEN基因的mRNA表达等进行了研究。结果 染料木黄酮和大豆甙元对PC-3、LNCaP细胞抑制效应具有时间和剂量依赖性，具有诱导凋亡和引起坏死效应；染料木黄酮能诱导PC-3和LNCaP细胞的(PTEN)表达，而大豆甙元只能诱导LNCaP细胞PTEN表达。结论 PTEN基因表达的变化可能在染料木黄酮和大豆甙元抑制PC-3和LNCaP细胞中具有重要的意义。染料木黄酮和大豆甙元抑制PC-3和LNCaP细胞可能存在多种作用途径。     

葛根黄豆甙元固体分散物对自发性高血压大鼠血压的影响

本文研究了葛根黄豆甙元及其固体分散物对清醒的自发性高血压大鼠血压的影响。口服葛根黄豆甙元固体分散物300mg/kg,2h血压下降达高峰,收缩压下降12.8%,而等量的葛根黄豆甙元及PVP均无明显改变,葛根黄豆甙元固体分散物使自发性高血压大鼠血浆中血管紧张素下降52.4%,使wistar大鼠的PRA下降24.7%.麻醉猫iv.25mg/kg,收缩压下降18.6±10.6%,舒张压下降43.0±19.2%.