重楼总皂苷长循环脂质体的制备与表征

摘 要 目的： 制备重楼总皂苷长循环脂质体,并对其进行表征。方法: 以粒径、PdI、Zeta电位及包封率为评价指标,考察制备重楼总皂苷长循环脂质体的各个因素。并采用Malvern粒度仪测定脂质体的粒径分布、PdI及Zeta电位,透射电镜考察其形态,并考察长脂质体的稳定性。结果:重楼总皂苷长循环脂质体的平均粒径为（109.4±32.7） nm,PdI为（0.171±0.036）,Zeta电位为（-36.7±4.5） mV,包封率为（93.5±3.2）%;透射电镜显示脂质体粒径均一,成球状分布;长期稳定性研究表明,长循环脂质体在4 ℃条件下放置3个月稳定。结论: 重楼总皂苷长循环脂质体制备工艺简单易行,可以得到包封率高、稳定性好的脂质体制剂。     

土贝母皂苷甲长循环脂质体的制备及体外性质考察

目的 制备土贝母皂苷甲长循环脂质体（tubeimoside A long-circulating liposomes,TA-LC-Lipo）,并进行体外性质考察。方法 乙醇注入法制备TA-LC-Lipo;采用HPLC测定包封率及体外释放率;通过Marlvern激光粒径分析仪测定粒径和Zeta电位;肉眼观察法和紫外分光光度法评价其溶血作用。结果 确定处方为大豆磷脂浓度10 mg·mL^-1、药脂比1：10、大豆磷脂：胆固醇=4：1、DSPE-PEG 2000的摩尔含量为5%。制备得到的TA-LC-Lipo的平均粒径、PDI、电位、包封率分别为123.0 nm,0.134,-1.20 mV,86.2%。结论 制得的TA-LC-Lipo粒度分布均匀,包封率较高,有较好的缓释作用,并能有效改善土贝母皂苷甲的溶血现象。     

去氢骆驼蓬碱脂质体制备工艺优化及抗肝癌活性

目的 制备去氢骆驼蓬碱脂质体并对其制备工艺进行优化，评价脂质体的相关表征及对肝癌细胞的毒性。方法 用薄膜水化法制备去氢骆驼蓬碱脂质体。以包封率作为评价指标，以大豆卵磷脂和药物的质量比、大豆卵磷脂与胆固醇的质量比和超声时间作为评价因素对脂质体包封率的影响。并对脂质体的粒径、Zeta电位、外观和稳定性进行评价。CCK-8法对比去氢骆驼蓬碱和去氢骆驼蓬碱脂质体的抗肝癌细胞增殖活性。结果 最优制备工艺：大豆卵磷脂和药物的质量比为11.4：1，大豆卵磷脂与胆固醇的质量比为4.4：1，超声时间为33 min。在此条件下制备的脂质体的包封率为81.88%，粒径为143.65 nm，Zeta电位为-12.68 mV，低温环境稳定性良好，具有缓释效应。去氢骆驼蓬碱脂质体的抗肝癌细胞增殖活性大于裸药。结论 所制得的去氢骆驼蓬碱脂质体包封率和稳定性均符合标准。将去氢骆驼蓬碱制备成为脂质体能提高其抗肝癌细胞增殖活性。     

达托霉素脂质体的制备和体外释放度考察

摘 要 目的：制备达托霉素脂质体,并考察其体外释放度。方法: 采用主动载药法制备达托霉素脂质体,激光粒度测定仪测定脂质体的粒度及其分布、Zeta电位,高效液相色谱仪测定包封率和体外释放度。结果: 达托霉素脂质体粒径为109.5 nm,多相分散系数为0.042,Zeta电位为-6.48 mV,凝胶柱法和离心法测得的包封率分别为50.8%和50.3%。体外释放度显示：相比于注射用达托霉素,达托霉素脂质体具有良好的缓释效果。结论:本方法制备的达托霉素脂质体,粒径均匀,能够实现药物的缓慢释放,减少给药次数。     

紫草素钠脂质体的制备及性能研究

目的 研究紫草素钠脂质体的制备工艺并考察其性质,旨在开发一种安全高效的紫草新型制剂。方法 利用碱溶酸提法纯化紫草提取物,并采用乙醇注入法制备紫草素钠脂质体,测定其形貌、粒径和Zeta电位。利用高效液相建立左旋紫草素含量测定方法,并考察了脂质体包封率和体外释放性能。结果 紫草素钠脂质体平均粒径为104.2 nm左右,且大小均一,成正态分布;Zeta电位为-14.8 mV;左旋紫草素在5~50 mg/L范围与峰面积呈良好的线性关系,相关系数为0.999 9;紫草素钠脂质体的包封率为43.67%,药物累积释放量为65.82%。结论 成功制备了紫草素钠脂质体,具有较高的包封率和体外释放率。     

叶酸受体靶向伊马替尼pH敏感脂质体的制备工艺及质量评价研究

摘 要 目的：运用改良的硫酸铵梯度法制备叶酸受体靶向伊马替尼pH敏感脂质体（FSLI）,并评价其质量。方法: 采用改良的硫酸铵梯度法制备FSLI,以包封率为指标进行制备工艺的优化;采用琼脂糖凝胶CL 4B柱分离脂质体和游离药,HPLC法测定FSLI的包封率;运用Zeta PALS粒径电位分析仪测定脂质体的平均粒径及Zeta电位,透射电镜观察脂质体的形态;运用动态透析法考察FSLI在不同pH环境中的药物释放情况,并考察FSLI在不同pH、37℃水浴中的粒径随时间的变化情况。结果: 制得的FSLI为圆形或类圆形的大单室脂质体,平均粒径为（155.2±1.92）nm,Zeta电位为 （29.36±3.21）mV,平均包封率为（90.7±1.70）%。FSLI在pH 7.4的中性环境中,药物释放缓慢,24 h累积释放度为2.76%,而在pH 5.5的酸性环境中,药物释放显著加快,24 h累计释放度均达到93.2%,表现出非常强的pH敏感性能。FSLI在pH 7.4的中性环境中不具有融合性能,而在pH 5.5的酸性环境中,粒径迅速增大,脂质体发生融合。结论:采用改良硫酸铵梯度法制备的FSLI,能获得较高的包封率,并具有良好的pH敏感性能。     

全反式维甲酸前体脂质体的制备及体外评价

目的:制备维甲酸前体脂质体,并对其体外性质进行考察。方法:采用乙醇注入结合冷冻干燥法制备前体脂质体;微柱离心-高效液相色谱法测定脂质体的包封率;并进一步对其粒径、Zeta电位、血浆释放率及乙醇残留量进行测定。结果:所制备的前体脂质体包封率为95.2%,Zeta电位为-(28.4±17.5)mV,粒径为(170±29)nm,乙醇残留量为3.98%。结论:乙醇注入结合冷冻干燥法制备的维甲酸前体脂质体包封率高,粒径均匀,稳定性好。     

白术挥发油脂质体的制备及质量考察

目的制备白术挥发油脂质体并考察其性质。方法采用薄膜分散法制备白术挥发油脂质体,正交设计优化处方,低温高速离心法分离脂质体和游离药物,HPLC测定脂质体的包封率,并测定其zeta电位和粒径,考察其稳定性。结果白术挥发油脂质体包封率为62．7％,zeta电位为36．65mV,平均粒径为206．9nm。结论薄膜分散法制得的白术挥发油脂质体包封率高。粒径分布均一,稳定性较好。     

苯丁酸氮芥脂质体的制备及处方因素考察

目的 制备苯丁酸氮芥脂质体并优化其处方。方法 薄膜超声分散法制备苯丁酸氮芥脂质体,采用微柱离心-HPLC法测定其包封率,以包封率为考察指标,研究膜材比、药脂比、水相介质pH值以及磷脂浓度等因素对脂质体包封率的影响;通过正交试验对处方进行优化,并进行质量评价。结果 苯丁酸氮芥脂质体优化后的制备处方为胆固醇与磷脂质量比1∶3、药脂比1∶10、水相介质pH值为7.4、磷脂浓度为0.3%。按该处方制得的苯丁酸氮芥脂质体包封率>87%,平均粒径为84.71 nm,PDI为0.167。结论 优选处方稳定可行,制备的苯丁酸氮芥脂质体包封率高、粒径小且均匀。     

基于pH梯度载药技术的咪喹莫特脂质体的制备工艺研究

目的 根据咪喹莫特的理化性质,利用pH梯度主动载药技术制备脂质体,考察其性状、粒径、表面电荷及体外释药特征。方法 葡聚糖凝胶滤过法测定脂质体的包封率,以包封率与成型性为主要指标筛选制备方法,考察水化液的种类、pH值、离子强度及pH梯度载药、磷脂-胆固醇比例、脂药比、维生素E用量对包封率的影响;正交试验优化咪喹莫特脂质体的处方,考察脂质体样品在0~4℃下的稳定性。结果 按处方咪喹莫特50 mg、大豆卵磷脂400 mg、胆固醇130 mg、油酸10 mg、维生素E 5 mg、柠檬酸pH 2.5缓冲液5 mL,采用薄膜分散法工艺制备脂质体样品,并进行pH梯度主动载药,pH值调至7.0。制得的咪喹莫特脂质体呈白色均匀的混悬液,脂质体微粒圆整,分散性好,粒径（347±21）nm,包封率（81.2±1.9）%,Zeta电位（-12.19±1.7）mV。结论 pH梯度主动载药技术适于咪喹莫特脂质体的制备。     

Synthesis and evaluation of 2,6-piperidinedione derivatives as potentially novel compounds with analgesic and other CNS activities

New 2,6-piperidinediones 2_a–g and 4_a–d were prepared by initial condensation of aromatic aldehydes or cycloalkanones with cyanoacetamide to give α-cyanocinnamides l_a–g or cycloalkylidenes 3_a,b which underwent Michae1 addition with ethyl cyanoacetate or diethylmalonate. Compounds 4_a–d were alkylated by various alkyl halides to produce the N-alkylated 2,6-piperidinedione derivatives 5_a–m. Some new selected compounds 2_a–c,f, 4_a–d & 5_e,h,j were pharmacologically evaluated for potential anticonvulsant, sedative and analgesic activities. These compounds exhibited significant anticonvulsant and analgesic effects after a single I.P. administration 100 mg/kg b.wt. . On the other hand all the investigated compounds induced hypnotic activity and prolonged the phenobarbital sodium- induced sleep as compared with the control group and the most potent compound was found to be 2_f.     

EFFECT OF POLICOSANOL SUCCESSIVE DOSE INCREASES ON PLATELET AGGREGATION IN HEALTHY VOLUNTEERS

Policosanol is a cholesterol-lowering drug with hypocholesterolemic effects demonstrated in experimental models, healthy volunteers and type II hypercholesterolemic patients. In addition, antiplatelet effects of policosanol have been shown in experimental models and healthy volunteers. The effect of successively increasing doses of policosanol on platelet aggregation was investigated in a randomized, placebo-controlled, double-blind study conducted in 37 healthy volunteers. The volunteers were on a placebo-baseline period (two tablets per day) for 7 days and thereafter they received randomly, under double-blind conditions, placebo or policosanol (10mgday⁻¹) for 7 days. After this period dosage was doubled to 20mgday⁻¹for the next 7 days and then again doubled to 40mgday⁻¹, while the control group received placebo tablets all the time. Platelet aggregation as well as coagulation time was measured at baseline and after each dosing step. Results showed that antiplatelet effects of policosanol were successfully enhanced throughout the study, thus suggesting a dose-dependent relationship. No significant effect was reached during the first dosing period, but significant reductions of epinephrine and ADP-induced platelet aggregation were observed after the second one. Finally, a significant inhibition of platelet aggregation induced by all the agonists was observed at the last dosing step. Coagulation time remained unchanged during the trial.     

鼻渊净胶囊的HPLC指纹图谱研究

目的 建立鼻渊净胶囊的高效液相色谱(HPLC)指纹图谱.方法 采用Agilent SB-C18(4.6 mm×250 mm,5μm)色谱柱,乙腈-水为流动相、以1.0 ml/min流速行梯度洗脱,检测波长210 nm,柱温30℃,洗脱时间为80 min.采用中药色谱指纹图谱相似度评价系统(2004A版)对检测出色谱进行...     

NEURAMIDE STIMULATES ADRENOCORTICOTROPIN BUT NOT PROLACTIN RELEASE FROM RAT PITUITARY

Neuramide (NMD), a substance found in crude preparations of porcine stomach extract, is a viral inhibitor that also has putative immunostimulatory effects. The effects of NMD on stress-hormone (ACTH and prolactin—PRL) release were assessed inin vivoandin vitrostudies. In the former, blood levels of corticosterone and PRL were measured in NMD-treated male rats.In vitroexperiments were performed to evaluate the effects of NMD and three of its fractions (obtained with high performance liquid chromatography) on ACTH and PRL release from perfused rat pituitary slices. NMD increased plasma corticosterone levelsin vivoand produced dose-dependent increases inin vitropituitary release of ACTH. No effects on PRL secretion were observedin vivoorin vitro. The stimulatory effects on ACTH release were caused by the NMD fraction with a molecular weight of >5000<10000Da.     

Investigation of the prevalence of tetQ, tetX and tetX1 genes in Bacteroides strains with elevated tigecycline minimum inhibitory concentrations

In this study, the antibiotic susceptibilities to tigecycline and tetracycline of 35 selected Bacteroides fragilis group strains were determined by Etest, and the presence of tetQ, tetX, tetX1 and ermF genes was investigated by polymerase chain reaction (PCR). tetQ was detected in all 12 B. fragilis group isolates (100%) exhibiting elevated tigecycline minimum inhibitory concentrations (MICs) (≥8 μg/mL) as well as the 8 strains (100%) with a tigecycline MIC of 4 μg/mL, whilst tetX and tetX1 were present in 15% and 75% of these strains, respectively. All of these strains were fully resistant to tetracycline (MIC ≥ 16 μg/mL). On the other hand, amongst the group of strains with tigecycline MICs < 4 μg/mL (15 isolates), tetQ, tetX and tetX1 were found less frequently (73.3%, 13.3% and 46.7%, respectively). All but two strains harbouring the tetQ gene in this group were non-susceptible to tetracycline, with a MIC > 4 μg/mL. These data suggest that in most cases tigecycline overcomes the tetracycline resistance mechanisms frequently observed in Bacteroides strains. However, the presence of tetX and tetX1 genes in some of the strains exhibiting elevated MICs for tigecycline draws attention to the possible development and spread of resistance to this antibiotic agent amongst Bacteroides strains. The common occurrence of ermF, tetX, tetX1 and tetQ genes together predicted the presence of the CTnDOT-like Bacteroides conjugative transposon in this collection of Bacteroides strains.     

INDIRECT PARASYMPATHOMIMETIC ACTIVITY OF THE CLASS III ANTIARRHYTHMIC SUBSTANCE / -SOTALOLIN VITRO: REVERSIBLE INHIBITION OF CHOLINESTERASE ISOENZYMES FROM BLOOD AND THE HUMAN CENTRAL NERVOUS SYSTEM

Inhibitory effects of the class III antiarrhythmic compound / -sotalol on acetylcholinesterase (AChE; EC 3.1.1.7) isoenzymes of both erythrocytes and the human caudate nucleus and on serum cholinesterase (ChE; EC 3.1.1.8) were studiedin vitrousing a spectrophotometric kinetic assay with acetylthiocholine (ASCh) as substrate. Sotalol concentrations in the assays varied from 0.32 to 3.2m . All isoenzymes studied were inhibited by / -sotalol in a reversible and concentration-dependent manner. Double reciprocal plots of the reaction velocity against varying ASCh concentrations revealed that / -sotalol reduced substrate affinity (apparent Michaelis constant, KM, increased) of serum ChE, but did not change the enzyme's maximal rate of ASCh hydrolysis (V_max). Thus, / -sotalol inhibition of serum ChE was of the competitive type (rate constant for reversible competitive inhibition: K_i=0.51m ). In contrast, / sotalol reduced the maximal reaction velocity of the AChE isoenzyme from the central nervous system (caudate nucleus), but had no influence on substrate affinity of the enzyme (K_Mwith ASCh unchanged) indicating purely non-competitive inhibition kinetics (rate constant of reversible non-competitive inhibition: K_i′=0.44m ). / -sotalol inhibition of erythrocyte AChE was of mixed competitive/non-competitive type (K_i=0.31m , K_i′=0.49m ). Non-competitive / -sotalol inhibition of caudate nucleus AChE and the non-competitive component of erythrocyte AChE inhibition cannot be overcome by increased concentrations of the cholinergic transmitter acetylcholine (ACh). Peak / -sotalol plasma levels as described in the literature for both humans (15μ ) and experimental animals (dogs: 18μ ; rats: 260μ ) as well as maximal myocardial concentrations of the substance (dogs: 46μ ; rats: 478μ ) are in the range of about 2% to 100% of the sotalol inhibition rate constants determined in the present paper for cholinesterase isoenzymesin vitro. Thus, / -sotalol inhibition of ACh hydrolysisin vivomay contribute to both the well known antiarrhythmic potential and proarrhythmic side effects of the compound.     

AMELIORIATION OF CHEMICALLY-INDUCED HEPATOCYTE INJURY BY CYCLOSPORINE A

Cyclosporine A, beside its current applications, possesses potential hepatoprotective effects. This study was directed to investigate the effect of Cyclosporine A pretreatment on hepatic injury due to carbon tetrachloride (CCl₄) and -galactosamine. Rats were injected by two successive doses of Cyclosporine A (5mgkg⁻¹day⁻¹). Six hours after the second dose, 1mlkg⁻¹of CCl₄was administered i.p. Effects associated with Cyclosporine A pretreatment were examined by using isolated hepatocytes and hepatocytes that were immobilized and continuously perfused. -Galactosamine (5m ) was added directly to the perfusion medium. After isolation, hepatocytes were examined histologically by light and electron microscopy, immobilized and perfused for further metabolic functional activity evaluation. Cyclosporine A pretreatmentin vivoproduced hepatoameliorative effects of various degrees which were statistically significant as manifested by: (1) an increased trypan blue exclusion after CCl₄; (2) an improved ureagenesis after CCl₄; (3) a reduction in the lipid droplets accumulation in the cytoplasm produced by CCl₄administration; (4) well preserved cytoplasmic organelles as mitochondria, endoplasmic reticulum ER, nuclear chromatin structures that were altered by CCl₄; and (5) an increased hepatocytes survival in the agarose gel matrix, reduction of LD leakage and improvement of ureagenesis after -galactosamine addition to the perfusion medium. The beneficial effect of Cyclosporine A pretreatment in modifying hepatotoxicity of chemical insults merits further studies.     

喙果黑面神化学成分研究

目的研究大戟科植物喙果黑面神(Breynia rostrata Merr.)的化学成分。方法利用硅胶、凝胶等色谱技术分离纯化化学成分,根据化合物的理化性质和光谱数据进行结构鉴定。结果从喙果黑面神的正丁醇萃取部分分离得到4个化合物,分别鉴定为6-O-甲基丙酰基-α-D-吡喃葡糖(6-O-methylpropanoyl-α-D-glucopyranose,1);4″-苯酚基-6-O-甲基丙酰基-β-D-吡喃葡糖苷(4″-phenolic-6-O-methylpropanoyl-β-D-glucopyranoside,2);1-O-没食子酰基-β-D-吡喃葡糖苷(1-O-galloyl-β-D-glucopyranoside,3);熊果苷(arbutin,4)。结论化合物1和2为新化合物,3和4均为首次从该种植物分离得到。     

EFFECTS OF 2-GUANIDINE-4-METHYLQUINAZOLINE ON GASTRIC ACID SECRETION IN RATS

In this study 2-guanidine-4-methylquinazoline (2-GMQ) appeared to decrease basal and stimulated gastric acid secretion, while structurally related compounds as dimethyl- biguanide, cyanoguanidine and 2-cyanoamino-4-methylpyrymidine did not. Thus, there is an antisecretory effect when the biguanide group is associated with a lipophilic structure. The antisecretive effects exerted by 2-GMQ are associated with anti H₂-histamine activity.The anti H₂-histamine nature of the effects of 2-GMQ was confirmed by the capacity of this compound of depressing the chronotropic activity of the isolated guinea pig auricle increased by histamine, as well as relaxant activity in rat uterus contracted by histamine, since both preparations are rich in H₂-histamine receptors.     

栝楼不同药用部位质量控制的研究进展

瓜蒌子、瓜蒌皮、瓜蒌、天花粉来源于栝楼的不同药用部位,4味药材均为常用的大宗药材,现行版《中国药典》对其制定的质量标准过于简单,无法科学合理地控制其质量。本文对瓜蒌子、瓜蒌皮、瓜蒌、天花粉安全性和有效组分的研究进行综述,明确了相关研究存在的问题并针对问题提出建议,为科学全面的药材及饮片标准的制定提供参考依据。