芦荟多糖含量测定及芦荟膏体外透皮吸收的实验研究

目的:研究芦荟膏中各功能成分体外透皮吸收的能力。方法:以Wistar大鼠的背部皮肤为透皮实验原料,每隔一定时间通过分光光度法和高效液相色谱法测定透皮后接收池内芦荟多糖及蒽醌类含量。结果:随着芦荟膏剂量的增加,渗透量逐渐增加,芦荟膏中芦荟多糖、芦荟大黄素、芦荟苷的渗透量随时间延长逐渐增加,但是渗透速率逐渐降低。结论:芦荟膏有较强的体外透皮吸收能力,芦荟膏经皮给药能充分发挥其作用。     

正交实验优化川陈皮素微乳凝胶剂促渗剂及体外释药评价

本文筛选了川陈皮素微乳凝胶剂的最佳透皮促渗剂并考察了其体外释药机制。采用正交实验设计,对离体家兔鼻粘膜进行体外渗透实验,以川陈皮素的累积渗透量及渗透速率常数为指标,优选最佳处方;采用扩散池法对川陈皮素微乳凝胶剂进行体外释药研究,并用无膜溶出法考察其释药机制。结果表明,不同促渗剂对川陈皮素的累积渗透量及渗透速率常数影响大小为:氮酮冰片丙二醇,且氮酮具有显著性差异(P0.05),微乳凝胶剂12 h的累积释药率为86%,符合Higuchi方程,其溶蚀量较少且与释药率无明显线性相关(r=0.9387)。可见,2%氮酮、2%冰片和1%丙二醇可作为最佳促渗剂处方在川陈皮素微乳凝胶剂中使用,且该制剂体外释药性能良好,有一定的缓释特性。     

淫羊藿苷促进体外培养骨髓间充质细胞成骨性分化活性强于蛇床子素

比较研究蛇床子素与淫羊藿苷处理对体外培养的大鼠骨髓间充质细胞(rat bone marrow stromal cell, rBMSC)成骨性分化的影响.从体外分离培养的大鼠骨髓间充质细胞,筛选出最佳的蛇床子素和淫羊藿苷处理的浓度为1×10-5 mol/L, 然后用最佳的浓度对体外培养的大鼠骨髓间充质细胞进行药物干预;在药物干预后的第3、6、9、12和15 d后测定碱性磷酸酶活性（alkaline phosphatase,ALP）和钙含量;第12 d 进行钙化结节茜素红染色;第12 h、24 h、48 h、72 h和96 h 对OXS、Runx-2、骨形态发生蛋白(bone morphogenetic protein,BMP-2)和collagen-I mRNA 表达水平进行real-time RT-PCR检测.结果显示,浓度为1×10-5 mol/L蛇床子素和淫羊藿苷干预均可提高体外培养的骨髓间充质细胞ALP活性,增加Ca含量,提高Runx、OXS、BMP-2和collagen-1 mRNA的表达水平.同时,淫羊藿苷在促进体外培养骨髓间充质细胞成骨性分化活性强于蛇床子素.     

王不留行黄酮苷软膏剂体外透皮吸收研究

为了研究渗透吸收促进剂氮酮用量对王不留行黄酮苷软膏剂体外经皮渗透性能的影响及为该化合物经皮给药系统的开发提供参考。本实验采用HPLC测定王不留行黄酮苷的含量,流动相为甲醇和水,检测波长280 nm。选取大鼠背部皮肤,通过Franz垂直扩散池考察王不留行黄酮苷软膏剂透皮性能,结果表明24 h内,不同浓度的氮酮对王不留行黄酮苷软膏剂透皮吸收均有一定的促进作用,其促渗作用为1%氮酮0.5%氮酮5%氮酮3%氮酮0%氮酮。本实验说明氮酮能促进王不留行黄酮苷软膏剂中的王不留行黄酮苷透皮吸收,以1%的氮酮促透效果最佳。     

VBE-1经皮渗透行为的考察及其对紫外线诱导皮肤色素沉着的干预作用

采用Franz扩散池考察溶液和混悬液的体外经皮渗透特性,计算混悬液和溶液中VBE-1的渗透动力学参数,并测定VBE-1在皮肤中的滞留量。溶液中VBE-1的稳态渗透速率显著提高,渗透时滞明显缩短,24 h单位质量皮肤累积滞留量提高了35%,VBE-1的经皮渗透行为得到了优化。制备VBE-1凝胶,选用棕黄色豚鼠为动物模型,考察VBE-1对紫外线诱导皮肤色素沉着的干预作用,结果显示2%VBE-1凝胶组的皮肤黑色素增加量明显低于空白基质组。VBE-1在较高浓度时对紫外线诱导的皮肤色素沉着有一定的干预作用。     

渗透促进剂对紫草素透过大鼠腹部皮肤的作用

研究不同浓度的丙二醇、氮酮和油酸对紫草素透过大鼠腹部皮肤的影响．实验结果表明,不同浓度的丙二醇对紫草素经皮渗透均有促进渗透作用,丙二醇浓度为10％时促渗效果最佳,油酸也具有促进紫草素的经皮渗透作用,但是在本实验中氮酮抑制紫草素的经皮渗透。     

蛇床子素对离体肺动脉环的作用北大核心CSCD

为了研究蛇床子素对离体肺动脉的作用,本研究游离人及健康SD大鼠的肺动脉血管和SD大鼠的肠系膜动脉血管,剪成长约3 mm的血管环,观察不同浓度的蛇床子素对人和大鼠离体肺动脉以及大鼠肠系膜动脉收缩的作用。结果表明蛇床子素（10-9~10-5mol/L）对人和大鼠苯肾上腺素预收缩的肺动脉具有浓度依赖性的舒张作用,对大鼠肠系膜动脉和正常的肺动脉无舒张作用。证实蛇床子素可舒张人和大鼠离体肺动脉环,其舒张作用具有浓度依赖性和组织特异性。     

β—环糊精包合荧光法监测蛇床子素的血药浓度

用β-环糊精(β-CD)为包合试剂的荧光法对兔体血浆中蛇床子素的血药浓度进行24h的监测,达峰时间为0.75 h,血中蛇床子素的含量在3.02×10-6～7.26×10-6g/ml之间,方法简便、快速、效果良好.     

小茴香挥发油贴剂体外释放和透皮性能的研究

本文主要对小茴香挥发油贴剂体外释放和透皮性能进行了研究。用高效液相色谱法(HPLC)测定小茴香挥发油在不同释放介质中的溶解度,选择30%聚乙二醇400-生理盐水作为满足漏槽条件的释放介质。按《中国药典》规定方法测定含不同稀释剂的小茴香挥发油贴剂体外释放量,24 h体外释放累积量依次为二乙二醇单乙基醚(Transcutol P)己二酸二异丙酯辛癸酸甘油酯空白肉豆蔻酸异丙酯,说明不同稀释剂对小茴香挥发油贴剂的释放影响较大。Transcutol P的释放效果最好,24 h体外释放百分含量为64.16%,其体外释放过程符合Higuchi方程,释放速率常数为1762.2μg/cm~2·h~2。因此,选择Transcutol P作为小茴香挥发油贴剂的稀释剂。用选定的稀释剂贴剂进行大鼠和小型猪腹部皮肤体外透皮性能的研究,体外透皮过程符合零级动力学方程,透皮速率分别为63.943μg/cm~2·h、6.134μg/cm~2·h,说明不同皮肤对体外透皮速率有影响。     

蛇床子素对离体肺动脉环的作用

为了研究蛇床子素对离体肺动脉的作用,本研究游离人及健康SD大鼠的肺动脉血管和SD大鼠的肠系膜动脉血管,剪成长约3 mm的血管环,观察不同浓度的蛇床子素对人和大鼠离体肺动脉以及大鼠肠系膜动脉收缩的作用。结果表明蛇床子素(10-9~10-5mol/L)对人和大鼠苯肾上腺素预收缩的肺动脉具有浓度依赖性的舒张作用,对大鼠肠系膜动脉和正常的肺动脉无舒张作用。证实蛇床子素可舒张人和大鼠离体肺动脉环,其舒张作用具有浓度依赖性和组织特异性。     

Methyl salicylate as a cutaneous stimulus: a psychophysical analysis

Two experiments were performed to examine the perceptual effects of methyl salicylate on hairy skin in humans. In the first experiment, the sensitivity to methyl salicylate (prepared in an ethanol and water vehicle and applied via filter paper) was measured in a paradigm that required subjects to report both the perceived intensity and the perceptual quality of the sensations they experienced. The results indicated that methyl salicylate could be reliably detected at concentrations between 3 and 12%. Peak perceived intensities increased with increasing concentration, and the dominant sensation quality reported was "burning". The second experiment, which measured the effect of methyl salicylate on the perception of temperature change, revealed that the compound enhances the perception of warming but does not affect the perception of cooling. For most subjects, methyl salicylate produced a hyperalgesia to heating. Overall, the data suggest that methyl salicylate probably produces its sensory effects via stimulation and/or sensitization of a population of cutaneous nociceptors.     

COX-2 contributes to the maintenance of flow-induced dilation in arterioles of eNOS-knockout mice

Our previous studies demonstrated that, in gracilis muscle arterioles of male mice deficient in the gene for endothelial nitric oxide synthase (eNOS), flow-induced dilation (FID) is mediated by endothelial PGs. Thus the present study aimed to identify the specific isoform of cyclooxygenase (COX) responsible for the compensatory mediation of FID in arterioles of eNOS-knockout (KO) mice. Experiments were conducted on gracilis muscle arterioles of male eNOS-KO and wild-type (WT) mice. Basal tone and magnitude of FID of arterioles were comparable in the two strains of mice. A role for COX isoforms in the mediation of the responses was assessed by use of valeryl salicylate (3 mM) and NS-398 (10 microM), inhibitors of COX-1 and COX-2, respectively. In eNOS-KO arterioles, valeryl salicylate or NS-398 alone inhibited FID (at maximal flow rate) by approximately 51% and approximately 58%, respectively. Administration of both inhibitors eliminated the dilation. In WT arterioles, inhibition of COX-2 did not significantly affect FID, whereas inhibition of COX-1 decreased the dilation by approximately 57%. The residual portion of the response was abolished by additional administration of Nomega-nitro-L-arginine methyl ester. Western blot analysis indicated a comparable content of COX-1 protein in arterioles of WT and eNOS-KO mice. COX-2 protein, which was not detectable in arterioles of WT mice, was strongly expressed in arterioles of eNOS-KO mice, together with an upregulation of COX-2 gene expression. Immunohistochemical staining confirmed the presence of COX-2 in the endothelium of eNOS-KO arterioles. In conclusion, COX-2-derived PGs are the mediators responsible for maintenance of FID in arterioles of eNOS-deficient mice.     

Evaluation of drug release profile from patches based on styrene-isoprene-styrene block copolymer: the effect of block structure and plasticizer

We prepared pressure-sensitive adhesive (PSA) patches based on styrene-isoprene-styrene (SIS) thermoplastic elastomer using hot-melt coating method. The liquid paraffine is added in the PSA matrices as a plasticizer to moderate the PSA properties. Three drugs, methyl salicylate, capsaicin, and diphenhydramine hydrochloride are selected as model drugs. The Fourier transform infrared spectroscopy, differential scanning calorimetry test, and wide-angle X-ray diffraction test indicate a good compatibility between drugs and matrices. Peppas equation is used to describe drug release profile. Different drug-matrix absorption, as indicative of drug-matrix interaction, accounts for the variation in release profiles of different drugs. Furthermore, atomic force microscopy and rheological studies of the PSA samples are performed to investigate the effect of SIS structure and plasticizer of PSA on drug release behaviors. For methyl salicylate and capsaicin, drug diffusion in the PSA matrices is the main factor controlled by the release kinetic constant k. The high [SI] diblock content and high plasticizer amount in matrix provide the PSA with a homogeneous and soften microstructure, resulting in a high diffusion rate. But for water-soluble drugs such as diphenhydramine hydrochloride, the release rate is governed by water penetration with the competition from diffusion mechanisms.     

中红侧沟茧蜂化学感受蛋白MmedCSP1的结合特征

化学感受蛋白是一类存在于昆虫化学感受器中的可溶性蛋白, 被认为与昆虫识别外界化学信息有关。本研究使用pGEX-4T-1表达载体在BL21 (DE3)异源表达系统中表达中红侧沟茧蜂Microplitis mediator化学感受蛋白MmedCSP1, 并通过亲和层析法纯化得到去表达标签的MmedCSP1;使用bis-ANS作为荧光配基, 在荧光分光光度计上研究它与50种气味标样的结合特征, 从而得到此类化学感受蛋白在中红侧沟茧蜂嗅觉识别中识别气味的种类。结果表明: MmedCSP1只能与水杨酸甲酯、戊烷、罗勒烯、β-紫罗兰酮、3, 4-二甲基苯甲醛、2-己酮和叶醇结合。但只有脂类化合物β-紫罗兰酮能在浓度为1 mmol/L下将bis-ANS从MmedCSP1中替换50%, β-紫罗兰酮与MmedCSP1的结合常数为16.89 μmol/L。这些结果提示MmedCSP1参与中红侧沟茧蜂对水杨酸甲酯、戊烷、罗勒烯、β-紫罗兰酮、3, 4-二甲基苯甲醛、2-己酮和叶醇等气味的识别过程, 且在不同气味中的识别过程中对于气味的运输能力有差异。     

Microdialysis studies of extracellular reactive oxygen species in skeletal muscle: factors influencing the reduction of cytochrome c and hydroxylation of salicylate

Identification and quantification of specific reactive oxygen species (ROS) is essential to allow greater understanding into the role that ROS play in tissues and extracellular fluids. Previous studies have examined the reduction of cytochrome c and the hydroxylation of salicylate to detect superoxide and hydroxyl activity, respectively, although the specificity of these assays has been the subject of debate. This study aimed to identify the factors influencing hydroxylation of salicylate and reduction of cytochrome c in microdialysates from skeletal muscle extracellular fluid. Mice were anesthetized and treated with either polyethylene glycol-tagged superoxide dismutase (PEG-SOD), desferrioxamine mesylate (desferal) or N(G)-nitro-l-arginine methyl ester (l-NAME). A further cohort of untreated mice was also studied. Microdialysis probes were placed into the gastrocnemius muscle and perfused with salicylate or cytochrome c prior to, during, and after a period of demanding electrically stimulated contractions. Microdialysates were analysed for the reduction of cytochrome c and hydroxylation of salicylate. Contractile activity was found to increase both the reduction of cytochrome c and the hydroxylation of salicylate in the microdialysates. The reduction of cytochrome c was greater in mice treated with l-NAME compared with control untreated mice and was attenuated in mice treated with PEG-SOD. The hydroxylation of salicylate was attenuated in mice treated with desferal while there was no effect of l-NAME compared with untreated mice. Data support the hypothesis that superoxide and hydroxyl radical activity are the major contributors to the reduction of cytochrome c and hydroxylation of salicylate respectively in microdialysates from skeletal muscle extracellular fluid and indicate that these ROS are increased by contractile activity in skeletal muscle extracellular fluid.     

盐酸小檗碱缓释片的研制

目的:研究盐酸小檗碱缓释片的配方与制备方法,考察其释放度。方法:以盐酸小檗碱释放度为考察指标,采用单因素试验法,考察了羟丙基甲基纤维素(HPMC)和乳糖的用量对药物体外释放行为的影响,并采用正交设计实验对处方进行优化,确定最佳处方。结果:最佳配方为HPMC-K4M的用量为10%,乳糖用量为20%,PVP的用量为3%,微晶纤维素的用量为20%。2 h累积释药量为30%,6 h累积释药量为60%,12 h累积释药量为90%。结论:按最佳配方制备的盐酸小檗碱缓释片有较好的缓释行为,基本上能满足缓释片的释放要求。     

中药川独活与浙独活根香豆素成分比较研究

中药川独活系伞形科植物重齿当归,又名重齿毛当归（Angelica Inserrata（Shan et Yuan）Yuan et Shan）（A.pubescens Maxim.f.biserrata Shan et Yuan）,为我国特产的常用药,广销国内外,有祛风、除湿、散寒、止痛等功用。四川、湖北、陕西等省都有栽培,野生重齿当归广泛分布于浙江、安徽、江西、四川等省。传统应用的中药独活为栽培的重齿当归,野生重齿当归仅在少数地区使用。为了弄清栽培与野生重齿当归间化学成分的差异,测定了它们的有效成分含量,为扩大利用野生重齿当归并为植物化学分类提供科学依据。     

Cell-free synthesis and transport of precursors of mutant ornithine carbamoyltransferases into mitochondria

Synthesis, mitochondrial transport and processing of ornithine carbamoyltrasferase (EC 2.1.3.3) were studied in mutant mice strains (sparse-fur, spf, and sparse-fur with abnormal skin and hair, spf-ash) which exhibit a deficiency in this enzyme. Spf mice have an increased amount (about 150% of control) of the enzyme with abnormal kinetic properties, whereas spf-ash mice have a decreased amount (about 10% of control) of the enzyme with apparently normal kinetic properties. Precursors of the mutant enzymes were synthesized in a reticulocyte lysate cell-free system. The hepatic level of translatable mRNA coding for the enzyme and the rate of the enzyme synthesis in liver slices of spf mice were 58 and 60% of the controls, respectively. In the case of spf-ash mice the activity of translatable mRNA for the enzyme was 10% of the controls. These results indicate that the decreased amount of ornithine carbamoyltransferase protein in spf-ash mice is due mainly to a decreased level of translatable mRNA for the enzyme, whereas the increase in the enzyme amount in spf mice is presumably the result of a decreased rate of enzyme degradation. The subunit molecular weight of the spf enzyme precursor was practically the same as that of the normal enzyme precursor (M_r 40 000). Both precursors synthetized in vitro could be taken up and processed similary to an apparently mature form (M_r 37 000). In the case of spf-ash enzyme, two discrete in vitro products were observed on sodium dodecyl sulfate polyacrylamide gel; one comigrated with the normal enzyme precursor and the other moved slightly slower. Both products appeared to be taken up and processed to the mature form of the enzyme.     

Study of prolactin permeation through the pericardium and its bioavailability

The prolactin (PRL) permeation through the pericardium depending on the species of origin (porcine, bovine and ovine) was studied, and the parameters of its bioavailability were calculated. An in vitro model using pericardium as a natural membrane and Frantz cell method was applied. Significant differences in permeation were observed depending on the species of origin. Within 5 h, 17.5% of bovine PRL, 27.2% of porcine PRL and 90.3% of ovine PRL permeated the pericardium. The amount of permeated ovine PRL was 3.3-fold higher than porcine PRL and 5.2-fold higher than bovine PRL. The maximum concentration of permeated PRL was reached in the thirtieth minute of the experiment and was the highest for ovine PRL (C(max) = 677.21 μg/cm2) and the lowest for bovine PRL (C(max) = 259.97 μg/cm2). Bioavailability of PRL through the pericardium is 3.3-fold greater for ovine PRL in comparison to porcine or bovine PRL. The relative extent of bioavailability for bovine and ovine prolactin versus the porcine PRL standard was 85.6% and 229.3%, respectively.     

Liquid Crystalline Systems for Transdermal Delivery of Celecoxib: In Vitro Drug Release and Skin Permeation Studies

Liquid crystalline systems of monoolein/water could be a promising approach for the delivery of celecoxib (CXB) to the skin because these systems can sustain drug release, improve drug penetration into the skin layers and minimize side effects. This study evaluated the potential of these systems for the delivery of CXB into the skin based on in vitro drug release and skin permeation studies. The amount of CXB that permeated into and/or was retained in the skin was assayed using an HPLC method. Polarizing light microscopy studies showed that liquid crystalline systems of monoolein/water were formed in the presence of CXB, without any changes in the mesophases. The liquid crystalline systems decreased drug release when compared to control solution. Drug release was independent of the initial water content of the systems and CXB was released from cubic phase systems, irrespective of the initial water content. The systems released the CXB following zero-order release kinetics. In vitro drug permeation studies showed that cubic phase systems allowed drug permeation and retention in the skin layers. Cubic phase systems of monoolein/water may be promising vehicles for the delivery of CXB in/through the skin because it improved CXB skin permeation compared with the control solution.KEY WORDS: celecoxib, drug delivery systems, liquid crystalline system, monoolein, skin permeation