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1.
以天然可生物降解的明胶为载体材料,液体石蜡为油相,Span80为乳化剂,采用正交试验优化空白明胶微球的乳化法制备工艺,并在此基础上制备了恩诺沙星明胶微球。结果显示,含药微球平均粒径为12.35μm,粒径7~30μm的微球占总数的92.3%,符合肺靶向的要求。恩诺沙星明胶微球载药量为20.67%、包封率为43.62%,动态透析法研究体外释放特性,符合Higuchi规律,释药t1/2比原药延长了约6倍,表明有明显的缓释功能。在37℃、相对湿度值(RH)75%考察3月,几乎无变化。兔体内分布试验表明具有明显的肺靶向性,肺中药代动力学行为符合三室开放模型。  相似文献   

2.
为了优选恩诺沙星淀粉微球的最佳制备工艺,试验将反相乳液聚合法与包埋载药法结合起来,以可溶性淀粉为载体、环氧氯丙烷为交联剂,制备恩诺沙星淀粉微球;以载药量和包封率为指标,通过L9(34)正交试验对制备工艺进行优化,采用扫描电镜观察载药微球的粒径大小及形态。结果表明:最佳工艺条件为淀粉4 g、恩诺沙星0.04 g、交联剂1.0 g、乳化剂0.8 g、反应时间2 h;按照此优化工艺参数制得的载药微球的总载药量为2.53%、包封率为89.72%;恩诺沙星淀粉微球大小较均匀,形态圆整,分散性较好,粒径为60μm左右;在最初2.5小时时释药量约为43.12%,至第8小时时释药量达80.69%,之后逐步释放,到第10小时时累积释药量占总药量的82.51%。说明此制备工艺可行,所制得的恩诺沙星淀粉微球具有一定的缓释效果。  相似文献   

3.
用聚乳酸羟基乙酸共聚物(PLGA)将鸡堆型艾美耳球虫重组表达质粒pcDNA3.1-3-1E包封,采用水包油包水(W/O/W)双重乳化方法制备pcDNA3-3-1E/PLGA微球。通过正交试验设计优化PLGA微球制备工艺,考察PLGA浓度、聚乙烯醇(PVA)浓度、超声功率、复乳搅拌时间对评价指标(即微球粒径大小、包封率、载药量)的影响,确定制备微球的最佳工艺条件。测定微球的形态、粒径、完整性、质粒DNA包封率、载药量和释放程度;进行体外模拟鸡胃液和肠液试验,观察微球体外释药效果。结果显示,当PLGA浓度为8%、PVA浓度为1.5%、超声功率为60W、复乳搅拌6h为微球制备的最佳工艺参数,在光镜下呈散在圆形,粒径小于12μm。微球的包封率、载药量分别为84.25%和4.46%,裸质粒与微球中质粒超螺旋比例差距不显著,这表明在包被过程中的超螺旋质粒未发生明显的降解。在模拟鸡的胃肠液累积释放试验中,它的累积释放能力依次为pH 3.0〉pH 7.4,载药微球在模拟鸡的胃肠液中24h释放26.8%,模拟肠液中24h释放11.2%,30d时体外累积释放率为81.7%,表明微球具有一定的缓释效果。  相似文献   

4.
分别用水中干燥法和油中干燥法制备盐酸多西环素微囊,比较各自制得的微囊质量参数及其体外释药特性,以期为盐酸多西环素缓释制剂提供科学依据.以乙基纤维素为囊材,通过正交设计分别考察各因素对微囊质量的影响,评定微囊的大小、形态、载药量、包封率等质量指标,以释放度实验研究其释药特性.结果显示,水中干燥法所制得微囊粒径20 ~ 30 μm,包封率为87.3%;油中干燥法微囊粒径范围为200~400μm,包封率为93.7%.上述结果表明油中干燥法所得微囊粒径较大,包封率、载药量均明显高于水中干燥法制得的微囊;体外释药实验表明,微囊化大大延缓了盐酸多西环素的释放时间.  相似文献   

5.
本试验旨在制备黄体酮聚乳酸微球,并考察其体外释药性能。以包封率、载药量为主要评价指标,考察制备黄体酮微球的主要影响因素,筛选出最佳工艺条件。扫描电子显微镜观察微球形态,紫外—可见分光光度法测定微球的包封率、载药量和体外释药特性。最佳工艺所制备的微球光滑、圆整、均匀、分散性好,包封率为(80.60±1.00)%,载药量为(10.63±0.05)%,在7 d内累积释药率达53.41%。制备微球包封率和载药量高,具有明显的缓释效果,能有效地延长药物作用时间。  相似文献   

6.
用星点设计-效应面法优化硫氰酸红霉素明胶微球的处方,以期得到分散性好、粒径符合要求的明胶微球。本研究采用乳化-化学交联法制备,以明胶浓度、油水比例、乳化剂浓度为自变量,微球的平均粒径、载药量、包封率、跨距为因变量对自变量的各水平进行多元线性回归和二项式拟合。根据因变量效应面法选取较佳工艺,并在此基础上制备了硫氰酸红霉素微球,且进行了优化处方的验证。结果显示,二项式模型拟合效果较多元线性回归要好,最佳优化处方为明胶浓度0.156g/mL、油水比例12∶2、乳化剂浓度0.03g/mL,根据优化工艺制备的微球分散性好,平均粒径、载药量、跨距、包封率分别为12.51μm、21.28%、1.51和84.39%。体外释药特性研究表明,该微球符合一级方程规律,具有明显的缓释效果。通过星点设计-效应面法成功建立了处方优化模型,且预测性良好。  相似文献   

7.
市售伊维菌素制剂存在生物利用度低,释药峰谷浓度差异大等问题,本文以明胶为囊材,采用单凝聚法制备伊维菌素长效注射微胶囊油混悬剂。以微胶囊的粒径、载药量和包封率为制备工艺的优化指标,采用分光光度法测定微胶囊内药物含量及包封率。结果显示:最佳工艺制备的微胶囊的平均包封率为63.2%,载药量为18.3%,微胶囊的正圆度高、表面平滑,粒径分布在20~50 μm,药物呈缓慢持续释放,体外累计释放率18 h为30.0%,44 h后仅为51.0%。伊维菌素微胶囊制剂可大大增加体内留存时间,提高生物利用度,缓释效果显著。  相似文献   

8.
通过比较3种不同质量比的两嵌段共聚物制备的聚合物胶束,优化恩诺沙星聚合物胶束的制备工艺,并考察该胶束的理化性质和体外释药特性。以自乳化溶剂挥发法制备恩诺沙星聚合物胶束,并采用单因素法优化处方;HPLC法测定其载药量、包封率、体外释药特性,激光粒度仪测定其粒径及分布,红外分光光度法(IR)确证含药胶束特征。结果显示,采用PLA16000-mPEG2000(聚乳酸-聚乙二醇单甲醚)共聚物为载体,以丙酮为有机溶剂,所制备胶束平均粒径为(117.2±8.2)nm,载药量为(3.3±0.17)%,包封率为(32.3±1.70)%;相对于另外2种材料制备的胶束有较好的载药量,且IR确证药物已被包封在胶束中。恩诺沙星胶束体外释药试验表明其具有一定的缓释特性。  相似文献   

9.
生长激素释放肽-6缓释微球的制备及其对动物生长的影响   总被引:3,自引:0,他引:3  
以生物降解材料乳酸乙醇酸共聚物(PLGA,LA-GA 8515)为载体,采用复乳-液中蒸发法制备含生长激素释放肽-6的乳酸乙醇酸共聚物微球,并通过体外药物释放试验评价载药微球的释药特征.结果得到收率、粒径大小和分布及含药量均满意的微球,其中包封率为100%,平均体积径为3.45μm,收率为79%.在37℃、pH7.0的生理等渗缓冲液中,首日释药19.19%,其后以平均日释药3.23%的速度释药25 d.小鼠肌肉注射微球30 d后,累积增重比注射生长激素释放肽-6、生理盐水分别高22.56%(P<0.05)和53.17%(P<0.01).结果表明,生长激素释放肽-6乳酸乙醇酸共聚物微球有望发展成为新型长效制剂.  相似文献   

10.
阿维菌素缓释明胶微囊制备工艺及其体外释药特性   总被引:5,自引:0,他引:5  
以生物可降解材料明胶为囊材,采用单凝聚法制备了阿维菌素明胶微囊,通过L9(34)正交试验设计,对微囊制备工艺进行了优选,所得微囊粒径在2~70μm,其中20~50μm的占78%.药物包封率为(87.61±1.41)%,载药量为(15.77±0.23)%.体外释药试验,微囊释药符合一级动力学特征,t1/2=9.2d,比原药提高5.4倍,表明所制备的明胶微囊具有一定的缓释药物效应.  相似文献   

11.
本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。  相似文献   

12.
用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10~0.82μg/g。表明:蜂蜜应视为天然富硒营养品。  相似文献   

13.
乳酸杆菌益生作用机制的研究进展   总被引:2,自引:0,他引:2  
乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和 Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。  相似文献   

14.
以国际标准强毒R株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离MG,并收集感染鸡所产蛋分离MG。结果表明,人工感染48小时后上、下呼吸道及肺已被全面感染,96小时气囊已被感染,120小时输卵管已能分离到MG,卵巢始终分离不到MG。人工感染鸡自144小时便能在其所产蛋中分离出MG。药物治疗能在72小时内消除感染,油乳剂苗则需24天后逐渐降低蛋内MG分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内MG,但以研制的种蛋浸泡剂药浴效果为最好。  相似文献   

15.
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。  相似文献   

16.
Reasons for performing study: Clinical experiences indicate that centesis of the lateral compartment of the femorotibial joint is often unsuccessful. Objective: To determine the accuracy of 2 published and 2 unpublished techniques of centesis of the lateral compartment of the femorotibial joint. Hypothesis: It was hypothesised that a drug can be administered into the lateral compartment of the femorotibial joint via a diverticulum of this joint that surrounds the medial aspect of the long digital extensor tendon and that this technique is more accurate than described techniques of centesis of this compartment. Methods: Twenty‐four stifles of 12 horses were divided equally into 4 groups and a radiocontrast medium injected into the lateral compartment of the femorotibial joint of each group using a hypodermic needle inserted: 1) caudal to the lateral patellar ligament and proximal to the tibial plateau, 2) caudal to the long digital extensor tendon and proximal to the tibial plateau, 3) between the long digital extensor tendon and bone of the extensor groove of the tibia or 4) directly through the long digital extensor tendon until it contacted bone. Twelve veterinary students who had no experience using any of these techniques performed the injections. Accuracy of each technique was determined by examining radiographs obtained after injecting the contrast medium. Results: The most successful technique for arthrocentesis was by inserting a needle through the long digital extensor tendon. This approach was successful in all attempted cases, whilst other techniques had lower rates of success. Conclusions: The lateral compartment of the femorotibial joint can be accessed accurately by inserting a needle through the long digital extensor tendon as it lies within the extensor groove. Other techniques may not be as accurate for clinicians inexperienced in arthrocentesis of the lateral compartment of the femorotibial joint.  相似文献   

17.
This experiment was aimed to study the nutritional content and value of the muscles of two mallards (White feather mallard and mallard),and provide basic data and theoretical basis for the development and utilization of mallard meat products.60 White feathered mallards and mallards (30 for each breed,half of male and female) were chosen,and the composition and content of pectoral muscle crude protein,crude fat,cholesterol,amino acids,fatty acids,trace elements and vitamins were determined according to national standards and the nutritional values of muscle were evaluated.The results showed that the content of crude protein in muscle of White feather mallard was significantly lower than that of mallard (P<0.05).17 kinds of amino acids with contents higher than 0.01% were detected in the muscles of the two kinds of mallards,among which the contents of threonine,histidine,serine and proline in the muscles of the White feather mallard were significantly higher than those of mallard (P<0.05).The contents of lysine,glutamate and arginine were significantly lower than those of mallard (P<0.05).13 kinds of fatty acids with contents higher than 0.01% were detected,and the contents of stearic acid and oleic acid were significantly lower than those of the mallard.9 mineral elements (sodium,magnesium,potassium,calcium,manganese,iron,copper,zinc and selenium) in two kinds of mallards were detected,and there was no significant difference between the two kinds of mallards (P>0.05).8 kinds of vitamins were detected,and the content of vitamin B1 in muscle of White feather mallard was significantly higher than that of mallard (P<0.05),but the contents of vitamin D and vitamin E were significantly lower than that of mallard (P<0.05).The ratio of amino acids in muscle of two kinds of mallards was close to the ideal model recommended by WHO,which was rich in mineral elements and vitamins for human body,and had a broad prospect of development and utilization.  相似文献   

18.
本试验旨在研究两种绿头鸭(白羽绿头鸭和绿头鸭)肌肉营养组成和价值,为绿头鸭肉产品的开发利用提供基础数据和理论依据。选择白羽绿头鸭和绿头鸭60只(每个品种各30只,公母各半),依照国家标准测定胸肌粗蛋白质、粗脂肪、胆固醇含量及氨基酸、脂肪酸、微量元素和维生素的组成和含量,并对胸肌进行氨基酸评价及脂肪酸营养价值评价。结果显示,白羽绿头鸭肌肉粗蛋白质含量显著低于绿头鸭(P<0.05);两种绿头鸭肌肉中均检测到17种含量大于0.01%的氨基酸,其中白羽绿头鸭肌肉苏氨酸、组氨酸、丝氨酸和脯氨酸含量显著高于绿头鸭(P<0.05),赖氨酸、谷氨酸和精氨酸含量显著低于绿头鸭(P<0.05);检测到13种含量均大于0.01%的脂肪酸,其中白羽绿头鸭硬脂酸和油酸含量显著低于绿头鸭(P<0.05);检测到9种矿物质元素(钠、镁、钾、钙、锰、铁、铜、锌和硒),两种绿头鸭差异不显著(P>0.05);检测到8种维生素,白羽绿头鸭肌肉维生素B1含量显著高于绿头鸭(P<0.05),维生素D和维生素E含量显著低于绿头鸭(P<0.05)。两种绿头鸭肌肉氨基酸比例接近世卫组织推荐的理想模式,富含人体所需的矿物质元素和维生素,具有广阔的开发利用前景。  相似文献   

19.
应用光镜和透射电镜技术,观察了3~6月龄比格犬甲状腺的显微和超微结构。结果表明,比格犬甲状腺实质由滤泡和滤泡旁细胞构成。滤泡呈圆形或椭圆形,直径20.22~220.00μm,平均90.80μm;由单层立方上皮细胞围成,细胞高度3.04~7.11μm,平均5.18μm,电镜下可见功能状态不同的两型滤泡上皮细胞;滤泡旁细胞很多,直径4.40~8.82μm,平均6.23μm,位于滤泡之间或镶嵌于滤泡上皮细胞之间,也可聚集在一起形成滤泡样结构,胞质内含有大量的分泌颗粒,电镜下也可见两种类型的滤泡旁细胞。  相似文献   

20.
A retrospective review of records of 205 cats with histologically confirmed disease of the spinal cord was performed to identify the prevalence of disease in this nonrandomly selected population of cats. Clinical records were reviewed, and age, duration of neurologic illness, and clinical and histopathologic findings in cats with spinal cord disease were abstracted. Disease processes were classified into 7 categories and 23 groups. The most common diseases affecting the spinal cord of cats were feline infectious peritonitis (FIP), lymphosarcoma (LSA), and neoplasia of the vertebral column secondarily affecting the spinal cord. Information on age, onset and duration of clinical signs, and lesion localization at the postmortem examination in cats belonging to the 7 categories of disease were analyzed to create a practical list of differential diagnoses. Cats were also subcategorized into 3 groups based on their age at death. FIP was the most common disease of cats younger than 2 years of age. LSA and vertebral column neoplasia were the most common diseases affecting cats between 2 and 8 years of age. Vertebral column neoplasia was the most common disease affecting cats older than 8 years of age. Results of this histopathologic study showed that FIP and LSA were the most common disease processes affecting the spinal cord of cats. However, at least 21 other groups of diseases and their relative prevalence were identified.  相似文献   

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