盐酸川芎嗪羧甲基壳聚糖丝素蛋白微球的制备和体外释放特性

摘要：目的:制备一种包载盐酸川芎嗪的羧甲基壳聚糖丝素蛋白微球,以期延长药物的释放时间。方法:采用乳化-化学交联法制备盐酸川芎嗪羧甲基壳聚糖丝素蛋白微球;采用高效液相色谱法测定盐酸川芎嗪的含量;采用Box-Behnken设计-效应面法优化载药微球的制备工艺;考察盐酸川芎嗪注射液和载药微球的体外释放特性。结果:优化的制备工艺条件为:丝素蛋白质量浓度3.0 mg·ml-1、盐酸川芎嗪质量浓度2.0 mg·ml-1、搅拌速度600 r·min-1;制得的载药微球的粒径为（34.4±2.3）μm、包封率为（67.6±1.3）%（n=4）,与软件模型预测值接近,偏差绝对值均小于5%。盐酸川芎嗪注射液中的药物在60 min内已完全释放;而载药微球在30 min内药物快速释放,60 min后药物释放速率较缓慢,180 min时完全释放。载药微球在6种释放介质中的体外释放过程均符合Higuchi方程,体现出良好的缓释特性。结论:优化后的盐酸川芎嗪羧甲基壳聚糖丝素蛋白微球制备工艺简便易行,微球形态圆整,包封率载药量较高,体外释放具有缓释特性。     

挤出滚圆法制备盐酸多西环素肠溶微丸

目的应用挤出滚圆法及包衣锅包衣制备盐酸多西环素肠溶微丸,并对其性质进行考察。方法用挤出滚圆法制备了盐酸多西环素微丸,采用单因素考察和L9（34）正交设计筛选最优处方和工艺条件,再用包衣锅将微丸包肠溶衣,考察了微丸的粉体学性质及不同包衣增重微丸的体外释放情况。结果制得的盐酸多西环素肠溶微丸圆整度好,大小均匀,收率高。15%包衣增重的微丸在0.1 mol•L 1盐酸释放度＜10%,在pH6.8的缓冲液中释放度＞80%,体外释放较理想。结论该法制备工艺简单易行,重复性好,采用适当的包衣工艺,制得的盐酸多西环素肠溶微丸具备较理想的肠溶特征。     

盐酸多西环素调释微丸的制备及处方因素考察

选用HPMCP-55和HPMC E15作为包衣材料,制备盐酸多西环素调释微丸,并考察其处方因素和工艺.采用流化床底喷溶液上药法制备载药微丸,考察聚合物HPMCP-55和致孔剂HPMC E15之间的比例,聚合物包衣增重以及增塑剂用量和热处理对药物释放的影响.当HPMCP-55和HPMC E15的质量比为25:4,聚合物包衣增重为10%,增塑剂用量为5%时,药物释放行为符合要求.通过调整HPMCP-55和HPMC E15之间的比例,或选择恰当的包衣增重,能使盐酸多西环素载药微丸具备较理想的释放效果.     

眼用妥布霉素羧甲基壳聚糖微球的制备及体外释放性能研究

目的 制备眼用妥布霉素羧甲基壳聚糖微球,并评价其体外释药性能。方法 采用乳化-交联固化法制备妥布霉素羧甲基壳聚糖微球,并以微球的收率、粒径分布和包封率作为评价指标,使用Box-Behnken实验设计优化得到妥布霉素羧甲基壳聚糖微球的最优处方。通过马尔文激光粒度仪测定了微球的粒径分布,扫描电镜观察其微观结构,考察微球在人工泪液中的释药性能。结果 优化得到微球的处方组成：羧甲基壳聚糖质量浓度为3.5%,甲醛质量浓度为1.5%,Span-80质量浓度为0.8%;妥布霉素羧甲基壳聚糖微球的平均粒径为（12.3±0.4）μm,呈圆整球状分布,无聚集;体外释药前期较快,后期较为缓慢,药物释放符合Higuchi释药模型。结论 通过使用Box-Behnken实验设计优化制备得到妥布霉素羧甲基壳聚糖微球,制备工艺简易,重现性良好,具有较好的缓释性能,可进一步进行实验研究。     

正交试验优选羧甲基壳聚糖-醋甲唑胺纳米微球的制备方案

目的：制备羧甲基壳聚糖载药纳米微球,醋甲唑胺为模型药物,测量药物的包封率和纳米微球形态.方法：采用乳化交联法,在微乳液的基础上制备载药纳米微球,对可能影响药物包封率的处方因素进行优化设计,筛选出最优配方.结果：羧甲基壳聚糖溶液的浓度对包封率有显著性影响,三聚磷酸钠溶液浓度和醋甲唑胺药量对包封率未见影响.优化方案的载药纳米微球包封率为49.36％,其电镜下为较规整的球型纳米微球,平均粒径386.0 nm.结论：采用乳化交联法,可形成较高包封率的羧甲基壳聚糖-醋甲唑胺纳米微球.     

甲硝唑羧甲基壳聚糖缓释微球的制备及体外释放

目的:探讨乳化交联法制备甲硝唑羧甲基壳聚糖微球的最佳工艺,并了解微球体外释药规律.方法:按正交设计,考察不同羧甲基壳聚糖浓度、投药比、交联度、乳化转速等条件对质量指标的影响,选出最佳方案,并进一步检测微球的体外释放特性.结果:各因素对所制微球综合评分指标的影响大小依次为:乳化转速>投药比>交联度>羧甲基壳聚糖浓度,用优化的工艺制得微球50～200μm粒径分布百分数为48.86%,载药量为48.19%,包封率为37.46%,在pHI.2、6.8和7.6,3种缓冲液中的释放时间为6～8h.结论:本法所制微球工艺稳定.在体外具有缓释作用.     

分子筛效应对氟尿嘧啶白蛋白毫微囊释药速率的影响

目的：用分子筛理论和方法研究不同制备条件对白蛋白微囊内部孔径及释药速度的影响。方法：利用低压色谱仪采用分子筛层析的方法测定不同量的固化剂对化学交联固化法制备的白蛋白毫微囊药物释放速度的关系。结果：实验表明,在相同条件下制成 乳后以不同交联剂量制备的毫微囊药物释放速率不同。结论：交联剂的用量越大,毫微囊的内部孔径越小,药物的释放速度越慢。但是药物的性质也有一定的影响。     

依托泊苷鼻用壳聚糖微球的制备及体外释放度考察

目的研制依托泊苷鼻黏膜给药壳聚糖微球,对微球的制备方法及体外释放度进行考察.方法以壳聚糖为栽体,甲醛为交联剂,采用乳化交联固化法制备微球,对微球的粒径、形态及体外释药进行研究.结果微球的外观圆整,平均粒径为(46.9±0.7)μm,78.4 %的微球粒径在30～70μm范围内,体外释药符合Higuchi模型.结论依托泊苷壳聚糖微球制备工艺简单、稳定,包封率高,药物释放符合鼻腔给药要求.     

鼻用氟脲嘧啶壳聚糖微球的体外释放及溶胀影响因素

目的考察壳聚糖脱乙酰度、壳聚糖浓度、固化剂用量、固化时间以及介质pH值对氟脲嘧啶壳聚糖微球的体外释放与溶胀的影响。方法乳化化学交联法制备氟脲嘧啶鼻用微球,动态透析法检测微球的体外释放特性;根据微球吸水前后质量变化测定微球的溶胀率。结果壳聚糖的脱乙酰度越高、固化剂用量越大、固化时间越长则微球的溶胀越慢,微球的体外释放越慢;壳聚糖浓度的增加则使微球的溶胀度增加,体外释放量减少;释放介质的pH值对微球的溶胀性能影响很大,在酸性条件下微球溶胀度高且释药加快。结论影响壳聚糖微球溶胀的因素顺序为介质的pH值>固化剂用量>固化时间>壳聚糖浓度≈壳聚糖脱乙酰度;影响壳聚糖微球体外释放的因素顺序为固化剂用量>壳聚糖脱乙酰度>壳聚糖浓度,而固化时间和介质的pH值对体外释放无显著性影响。     

阿奇霉素羧甲基壳聚糖微球的处方优化及质量评价

目的 优化阿奇霉素羧甲基壳聚糖微球的处方工艺，对其进行表征和质量评价。方法 采用乳化交联法制备阿奇霉素羧甲基壳聚糖微球；在单因素试验的基础上，采用星点设计-效应面法优化其处方工艺；采用红外光谱分析法(fourier transform infrared spectrum, FTIR)、X-射线衍射法(X-ray diffraction, XRD)和扫描电镜对其结构形态进行分析；采用透析法考察其体外释放行为；通过测定微球在模拟唾液中的释放度评价其掩味能力。结果 最优处方工艺为油水体积比4.5,载体质量浓度为36 g·L^-1,固化时间为2.8 h,制得的微球包封率为(86.32±1.52)%,载药量为(12.08±0.14)%;微球表面光滑圆整，分布均匀；FTIR和XRD结果均证实阿奇霉素被包裹于羧甲基壳聚糖中；微球在pH 6.8磷酸盐缓冲液中8 h稳定释放；在模拟唾液中30 s的释放浓度低于其苦味阈值。结论 此制备工艺可行，制得的微球载药量和包封率较高，释药稳定，口感适宜。     

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.     

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,5 μm）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）对检测出色谱进行指纹图谱相似度评价。结果 建立了鼻渊净胶囊的HPLC指纹图谱,确定了20个共有峰,15个峰归属到各药材,其中5个峰确认了化学成分;10批样品的指纹图谱的整体相似度与对照图谱比较,均在90%以上。结论 所建立的鼻渊净胶囊指纹图谱有助于从整体上控制该制剂的质量。     

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.     

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.     

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.     

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.     

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。     

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.