【作者】 李丹；

【导师】 宁长申；

【作者基本信息】 河南农业大学 ， 预防兽医学（专业学位）， 2015， 硕士

【摘要】 伊维菌素作为抗寄生虫药物有许多非常突出的特点,例如杀虫活性高,抗虫谱广,对大多数体内外寄生虫均有良好的治疗作用;能够应用于多种动物;可通过多种途径给药,包括口服、皮下注射以及肌肉注射等方式;使用安全,推荐剂量使用不会出现中毒作用,而且没有致畸和致癌作用。空心纳米SiO₂是一种多孔无机纳米材料,特点是比表面积大、生物相容性良好、抗高机械强度和高热,同时由于表面极易引进其他很多功能团的生物分子,因而在生物学方面已被用于作为催化剂载体、用于酶的固定化和生物标记等方面,尤其是被用来研究药物缓释控释、靶向、智能给药等方面。本试验将不溶于水的伊维菌素溶解到无水乙醇中,以纳米二氧化硅为载体,V乙醇:V硅溶胶的体积比分别为2.5:1和3:1的条件下制备出理论载药量分别为1%、2%和5%的三种含量伊维菌素-二氧化硅纳米载药颗粒,分别采用热重分析法和紫外分光光度计法检测三种药物的实际载药量,并通过体外缓释试验考察药物的吸附和缓释情况。结果如下:在V乙醇:V硅溶胶的体积比为2.5:1的比例下,热重分析法检测得到理论载药量为1%、2%和5%的实际载药量0.59%、1.51%和3.07%;在V乙醇:V硅溶胶的体积比为3:1的比例下,热重分析法检测得到理论载药量为1%、2%和5%的实际载药量为0.24%、1.09%和2.36%。在245nm条件下建立标准曲线方程y=34471.87631x+0.00162（R2=0.99991）,使用制备伊维菌素-二氧化硅纳米缓释颗粒时保存的上清液检测得到缓释颗粒的实际载药量和包封率,在V乙醇:V硅溶胶的体积比为2.5:1的比例下,理论载药量为1%、2%和5%的实际载药量为0.63%、1.58%和3.25%,包封率分别为78.24%、96.85%和75.07%;在V乙醇:V硅溶胶的体积比为3:1的比例下,检测得到理论载药量为1%、2%和5%的实际载药量为0.24%、1.05%和2.03%,包封率分别为25.59%、55.93%和5.94%。热重分析和紫外检测结果表明V乙醇:V硅溶胶的体积比为2.5:1时的载药量和包封率均高于其体积比为3:1时。体外缓释结果表明伊维菌素原药114h达到溶解平衡,而缓释颗粒则有良好的缓释行为,理论载药量为1%、2%的缓释颗粒在150h左右达到溶解平衡,理论载药量为5%的缓释颗粒在150h的累积缓释率才达到50%左右。累积缓释率随着载药量的增大而逐渐增大,但均小于原药的释放率。说明本试验制备的伊维菌素-二氧化硅纳米缓释颗粒的可控释放是可行的,且制备简单,成本低廉,是一种有望用于临床的新制剂。鸡球虫病是由柔嫩艾美耳球虫引起的一种肠道寄生虫病,在临床上通常以发病率和死亡率高为特征,给鸡养殖业造成了巨大的经济损失。该病对15-50日龄雏鸡危害尤为严重,死亡率能达到80%以上。经治疗后病鸡即使被治愈,但是其生长发育受阻,长时间得不到恢复。地克珠利是一种具有高效、广谱、低毒的抗球虫药,但是其不溶于水,给临床用药带来不便。为测定某生物科技有限公司研制的0.5%水溶性地克珠利预混剂的抗球虫效力,应用15日龄AA+肉鸡,每只经嗉囊1次接种1×105个抗地克珠利的柔嫩艾美耳球虫（Eimeria tenella）孢子化卵囊,按每千克饲料添加0.5mg、1mg、2mg水溶性地克珠利混饲,设1mg、2mg市售地克珠利和125mg尼卡巴嗪预混剂为对照,结果6个组的ACI分别为67、96、95.74、110.53、95.61、113.97,均在160以下,表明所用三种药物对该虫株的药效均较差;新方法制备的地克珠利通过提高吸收度并不能提高该药的抗球虫效果,且增加用药量仍不能提高该药的抗球虫效果;试验用虫株对尼卡巴嗪亦存在耐药性。更多还原

【Abstract】 As a kind of antiparasitic drug,ivermectin has many outstanding characteristics,such as high insecticidal activity,broad spectrum,being applied to a variety of animals,multiple administration routes including through the mouth,skin and muscle,application safety in recommended dose without poisoning effect,no teratogenesis and carcinogenesis effect.Hollow silica nanoparticle,a new type of inorganic porous nano-material,has the characteristics of large specific surface area,high mechanical strength and strong thermal stability.For its good biocompatibility,it has been widely applied as catalyst carrier,enzyme immobilization,biological markers,especially in the area of drug-loaded study,such as drug sustained and controlled release,drug targeting and intelligent drug delivery.In our research,insoluble ivermectin was dissolved into ethanol with different volume ratio to prepare the ivermectin-SiO₂ sustained release particle of different theoretical drug-loading rate,including 1%,2% and 5%.The actual drug-loading rate of ivermectin-SiO₂ was detected by thermogravimetric analysis（TGA）and ultraviolet spectrophotometer（UV）separately.The degree of drug adsorption and release was determined in vitro subsequently.When the volume ratio of ethanol and silica solution was 2.5:1,the actual drug-loading rate of ivermectin-SiO₂ by TGA was 0.59%,1.51% and 3.07%,corresponding respectively to the theoretical drug-loading rate 1%,2% and 5%.When the volume ratio was 3:1,the actual drug-loading rate was 0.24%,1.09% and 2.36% accordingly.On the other hand,the standard curve equation y=34471.87631x+ 0.00162（R2=0.99991）,established by ultraviolet spectrophoto-meter under 245 nm,was used to calculate the actual drug-loading rate and encapsulation rate.As the volume ratio was 2.5:1,the actual drug-loading rate figured out based on the above equation was 0.63%,1.58% and 3.25%,the encapsulation rate was 78.24%,96.85% and 75.07%.However,as the volume ratio was 3:1,the actual drug-loading rate was 0.24%,1.05% and 2.03%,the encapsulation rate was 25.59%,55.93% and 5.94% respectively.The above results obtained by the two methods showed that the actual drug-loading rate and encapsulation rate was better when the volume ratio of ethanol to silica solution was 2.5:1 than of 3:1.It was found that the ivermectin reached dissolution equilibrium at 114 hour,the ivermectin-SiO₂ had a significant sustained release effect.The ivermectin-SiO₂ with theoretical drug-loading rate of 1% and 2% reached dissolution equilibrium at about 150 hour,while the accumulative releasing ratio of 5% loaded-drug was just 50% at this time point.The accumulative releasing ratio increased with the drug-loaded amount.However it always cannot exceed the ratio of ivermectin.Together,it can be concluded that the design of the drug-loaded systems for controlled release of ivermectin is feasible.And the pharmaceutical preparation is expected to applied to clinical practice for the simple procedure and low cost.Avian coccidiosis,caused by Eimeria protozoan,is an intestinal parasitic disease that often causes huge economic losses to the poultry industry because of its high morbidity and mortality.The mortality rate of the disease is usually high,especially in the 15 to 50-day age chicks,the rate can be up to 80%.Once infection,it disturbs the growth of chicks for a long time even if they are cured.With high efficiency,low toxicity,broad spectrum anticoccidial effect,diclazuril is popular among the famers.However,diclazuril is insoluble in water,which is inconvenient for clinical medication.In order to test the anticoccidial efficacy of hydrosoluble diclazuril premix that is developed by a company,the 15-day age AA+ broilers were inoculated with 1×105 sporulated oocysts of E.tenella which were resistant to diclazuril through crop.Three drug treatment groups were designed in our research: hydrosoluble diclazuril premix of 0.5mg/kg,1mg/kg,2mg/kg,diclazuril premix of 1mg/kg,2mg/kg,Nicarbazin premix of 125mg/kg.The results showed that the anticoccidial index（ACI）of the six groups were 67、96、95.74、110.53、95.61、113.97 respectively,which were all bellow 160.This indicated that the efficacy on coccidiosis of the three kinds of drugs was poor.Although the hydrosoluble diclazuril had higher absorption rate,it also cannot kill coccidial effectively,even with increased dose.What’s more,the E.tenella strain used in our research was resistant to Nicarbazin.更多还原