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1.
本试验旨在制备玫瑰总黄酮脂质体(RTF-L),优化其处方,并对其质量进行评价。以薄膜-超声分散法制备RTF-L,采用超速离心-紫外分光光度法测定其包封率,以包封率为主要考察指标,采用正交试验优化其处方,并通过最优处方下制备的RTF-L的外观形态、粒径、粒度分布(PDI)、Zeta电位、体外累积释放率等评价其性质。结果显示,制备RTF-L的最佳处方为磷脂浓度0.3%,药物与磷脂比1∶15,水相介质pH 6.5,胆固醇与磷脂比1∶2;所制得的RTF-L包封率为(77.0±0.2)%,粒径为(155.40±2.11)nm, Zeta电位为(-21.03±1.24)mV,PDI为0.035±0.003,稳定性良好;体外累积释放试验结果显示,玫瑰总黄酮(RTF)溶液在6 h累积释放率为85.15%,基本释放完全,而RTF-L在6 h累积释放率为76.42%,与原药相比有一定的缓释作用。结果表明,优选处方稳定可行,所制备的RTF-L包封率高,粒径小且均匀,为RTF的进一步开发利用及其新剂型的研发提供一定的参考依据。  相似文献   

2.
优选玉屏风多糖脂质体的最佳工艺并对其进行表征验证。采用逆向蒸发法制备玉屏风多糖脂质体,以膜材比、脂药比和超声时间为考察因素,包封率为评价指标,采用L9(34)正交试验设计优选制备条件,以超速离心法测定包封率,体外释药试验验证,纳米颗粒分析仪和透射电镜测定其粒径大小与形态。制备玉屏风多糖脂质体的最佳工艺为膜材比8∶1,脂药比4∶1,超声时间90s,包封率88.38%,24h累积释放率73.45%,平均粒径132.65nm。制备的玉屏风多糖脂质体具有较高的包封率与良好的缓释作用,粒径和形态较均匀,重现性好。  相似文献   

3.
采用薄膜分散法制备阿莫西林脂质体,以粒径和包封率为指标评价其质量.前期以正交设计优化筛选出最佳制备工艺,以最优工艺制备阿莫西林脂质体,测定其平均粒径和包封率.实验所制得的脂质体的平均粒径为114.6 nm,包封率为64.89％.结果表明,采用薄膜分散法制备阿莫西林脂质体的方法可行,阿莫西林脂质体的制备为兽药新剂型的研究与应用提供了有价值的参考.  相似文献   

4.
为了解决替米考星现存制剂不足现状,开发出新型制剂,并对其理化特性进行研究,试验采用热均质超声法制备替米考星固体脂质纳米乳,并通过光学显微镜及纳米粒度仪观察、测定其理化特性;通过纳米乳的体外释放及抗菌试验,用细菌生长抑制和菌落计数法评价其对金黄色葡萄球菌的体外抗菌效果。结果表明:替米考星固体脂质纳米乳的粒径、Zeta电位、多分散系数分别(421.3±26.4)nm、(-10.3±0.3)mv,(0.30±0.09);替米考星固体脂质纳米乳在体外显示良好的缓释效果及持续的抑菌作用。说明替米考星固体脂质纳米乳是一种有前景的新制剂。  相似文献   

5.
为了优选黄芪多糖脂质体的最佳工艺并对其进行表征验证,采用逆向蒸发法制备黄芪多糖脂质体,以膜材比、脂药比和超声时间为考察因素,包封率为评价指标,采用L_(9 )(3~4)正交试验设计优选制备条件,以超速离心法测定包封率,纳米颗粒分析仪和透射电镜测定其粒径大小与形态。结果显示,制备黄芪多糖脂质体的最佳工艺为膜材比8∶1,脂药比4∶1,超声时间90 s,包封率93.77%,24 h累积释放率62.67%,平均粒径557 nm。表明制备的黄芪多糖脂质体具有较高的包封率与良好的缓释作用,粒径和形态较均匀,重现性好。  相似文献   

6.
为解决磷酸替米考星在养殖生产中适口性的问题,本试验以丙烯酸树脂为囊材,采用乳液-溶剂蒸发法制备磷酸替米考星微球,并采用高效液相色谱法对药物含量进行测定。将3批磷酸替米考星微球置于冰箱(4℃)、室温(25℃)与40℃(RH 75%)放置3个月,进行外观形态、粒径及其分布、载药量、体外释药特性的考察。结果表明:在该试验方法下制备的磷酸替米考星微球的形态良好,平均粒径为10.65μm,粒径7～30μm范围内的微球占总数的96.7%,载药量和包封率分别是28.36%、99.25%,分散性好,具有较好的热稳定性。  相似文献   

7.
【目的】 制备一种适用于治疗由金黄色葡萄球菌小菌落变异株(Staphylococcus aureus small colony variants,SASCVs)引起奶牛乳腺炎感染的槲皮素-替米考星混合物纳米粒,评价其对SASCVs菌株的抗菌活性。【方法】 通过对槲皮素(0.05、0.10、0.15和0.20 g)和替米考星原料药用量(0.2、0.3、0.4和0.5 g)及转速(500、1 000、1 500 r/min)、反应时间(0.5、1.0、2.0 h)、反应温度(25、50、75 ℃)、溶剂浓度(5.0%、7.5%、10.0%)进行考察,以外观性状为指标,筛选槲皮素-替米考星混合物纳米粒最优配方和制备条件;以微观形态、沉降体积比、再分散性、粒径和Zeta电位为指标,对制备的槲皮素-替米考星混合物纳米粒表征;通过琼脂扩散法、微量肉汤稀释法和体外杀菌曲线,对比槲皮素-替米考星混合物纳米粒和市售替米考星溶液对SASCVs菌株的抗菌活性,评价槲皮素-替米考星混合物纳米粒的优势。【结果】 当替米考星为0.4 g、槲皮素为0.1 g、溶剂为20 mL 7.5%的聚乙二醇溶液,在转速为1 000 r/min、反应时间为1 h、反应温度为50 ℃时,所制备的槲皮素-替米考星混合物纳米粒最优,其溶液外观性状显示颜色清亮,无沉淀和絮状物;微观形态显示该混合物纳米粒分布均匀,颗粒大小一致;沉降体积比为1,再分散性良好,平均粒径为741.9 nm,Zeta电位为-7.69 mV。替米考星标准品、槲皮素-替米考星混合物纳米粒和市售替米考星溶液对SASCVs菌株的抑菌圈直径分别为2.54、1.51和1.38 cm,对SASCVs菌株的最低抑菌浓度分别为1、1和2 μg/mL;体外杀菌曲线表明,槲皮素-替米考星混合物纳米粒对SASCVs菌株表现出明显的浓度依赖性。【结论】 本研究所制备的槲皮素-替米考星混合物纳米粒对SASCVs菌株具有较强杀菌能力,可为治疗由SASCVs菌株引起的奶牛乳腺炎提供基础研究资料。  相似文献   

8.
替米考星淀粉微球的制备及缓释性能的研究   总被引：2，自引：0，他引：2  
李仲谨  杨威  刘艳  赵燕  熊勇 《中国畜牧兽医》2010,37(11):230-234
以可溶性淀粉为原料,N,N′-亚甲基双丙烯酰胺为交联剂,采用包埋法制备了替米考星淀粉微球,通过L9(34)正交试验设计,以载药量和包封率的综合得分为指标,优化了替米考星淀粉微球的制备工艺;分别用激光粒度分布仪、扫描电镜和综合热分析仪对载药微球进行了表征。结果表明最佳工艺条件为：淀粉4 g、替米考星0.02 g、交联剂0.95 g、乳化剂0.75 g、反应时间1 h;影响因素的大小依次为：交联剂的质量＞替米考星和淀粉的投料质量比＞反应时间＞乳化剂的质量;按优化工艺参数制得的载药微球的总载药量2.24%,包封率为89.6%;替米考星载药微球具有一定缓释效果,其制备方法合理可行。  相似文献   

9.
为了制备苦参碱类生物碱传递体,并进行质量评价。以磷脂和胆固醇为膜材,1,2-丙二醇为表面活性剂,采用逆向蒸发法,应用以响应面法优化好的制备参数制备苦参碱类生物碱四元传递体,以高效液相色谱法测定包封率;并从外观形态、粒径、Zeta电位、变形率和包封率进行质量评价。结果显示制备的苦参碱类生物碱传递体其外观形状呈球形或椭球形,平均粒径为(184.2±2.7)nm,Zeta电位为(-47.4±2.3)mV,相对透膜速率为(76.09±0.34)%,RSD=1.00%,n=3;MAT和OMT的包封率分别为(80.43±0.98)%和(74.70±1.08)%,其RSD值分别为1.03%和1.11%(n=3)。苦参碱类生物碱传递体具有较高的质量和稳定性,其制备工艺简单可行、质量可控。  相似文献   

10.
磷酸泰乐菌素脂质体的制备及体外释放动力学研究   总被引：2，自引：2，他引：0  
主编 《中国兽药杂志》2010,44(10):24-28
为延长磷酸泰乐菌素在体内的作用时间,通过比较采用硫酸铵梯度法制备其脂质体制剂。以包封率为指标,分别考察磷脂与胆固醇之比、药脂比、硫酸铵浓度、孵化温度和孵化时间对包封率的影响,并在此基础上进行正交试验筛选最优处方。同时,对所得脂质体的形态、粒径及分布、包封率及体外释放动力学进行研究。结果显示,正交试验优化得到的最佳处方工艺如下,磷脂与胆固醇质量比为4∶1,药脂比为1∶10,硫酸铵浓度为300 mmol/L,体系pH值为7.0,孵化温度为50℃,孵化时间为20 m in。电镜下观察脂质体呈球形或类球形,分布均匀,平均粒径为6.526μm,且大部分在1μm~12μm之间,包封率为58.32%,体外释药符合W eibull方程(r=0.976 4)。研究证实硫酸铵梯度法制备磷酸泰乐菌素脂质体方法可行,包封率高,稳定性好,体外释药具有一定的缓释效应。  相似文献   

11.
试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。  相似文献   

12.
Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.  相似文献   

13.
1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.  相似文献   

14.
Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.  相似文献   

15.
Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.  相似文献   

16.
Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.  相似文献   

17.
The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.  相似文献   

18.
The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.  相似文献   

19.
The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.  相似文献   

20.
Infectious diseases have always been a terrible scourge for humans. The appearance of these plagues, as they were called without distinction, was generally connected to various conditions: asters, climatic changes or religious reasons. The concept of contagious, and then infectious, diseases came slowly. Variolation, i.e. transmission of ‘virulent’ matter to induce a natural disease and the immunity against it, was brought from Constantinople to England by Lady Montague, in 1721. This ‘variolation’ technique was also often performed in veterinary medicine against diseases like sheep-pox or pleuropneumonia. As ‘vaccination’ is the term generally accepted for ‘immunisation’, variolation can be the word designating such a technique. The second period of the history of immunisation began, in 1880, with the studies of Pasteur and his collaborators. A great number of bacterial vaccines were developed: dead, live but attenuated or only parts of pathogens. The viruses were produced in animals, then in eggs and at last, in tissue cultures. Second generation vaccines appeared with genetic engineering: recombinant vaccines, vector vaccines, nucleic acids vaccines, and markers vaccines, among others. These novel technologies can permit the development of new ones and improve the quality of the vaccines already existing.  相似文献   

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