系数倍率法检测伊维菌素脂质体含量的研究

伊维菌素脂质体是伊维菌素的一种重要新剂型,为消除辅料对伊维菌素含量测定的影响,采用系数倍率法在245nm和222nm处不经分离直接测定脂质体中伊维菌素的含量。结果表明,伊维菌素在4～28μg／mL范围内呈良好的线性关系,r=0．9999,平均回收率为104．6％。说明系数倍率法能消除脂质体中卵磷脂与胆固醇对伊维菌素含量测定的影响,可作为伊维菌素脂质体质量控制的有效方法。     

一例犬伊维菌素中毒的治疗

伊维菌素是兽医临床的常用药,对犬的耳螨、疥螨等都有特效,是一种高效、广谱、价廉的抗寄生虫药物。因其具有低毒性,且部分犬种对伊维菌素较敏感,易造成伊维菌素中毒。伊维菌素中毒目前没有特效药,只能通过对症治疗,同时加大静注剂量,促进代谢。     

伊维菌素脂质体的制备及质量控制研究

为研究伊维菌素脂质体 ,以卵磷脂和胆固醇为载体 ,采用注入法制备了伊维菌素脂质体 ,并应用紫外倍率系数法测定脂质体中伊维菌素的含量 ,采用高速离心法测定其包封率。结果表明 ,采用注入法制备的伊维菌素脂质体稳定性好 ,大小均匀 ,包封率效果良好 (77.42 %以上 ) ,紫外倍率系数法能消除辅料干扰 ,可作为伊维菌素脂质体质量控制的有效方法     

高效液相法测定伊维菌素粉的含量

伊维菌素是从阿佛曼链毒素菌发酵产物分离的独特物质经化学修饰而制成的。20世纪80年代中期的国外研究证实，伊维菌素对动物体内线虫和表寄生虫均有显著驱杀效果。1994年美国默沙东药厂生产伊维菌素，年销售额达4.95万美元，列居当年世界动物保健品市场的10大产品榜首。由伊维菌素加一定辅料配制而成的伊维菌素粉，     

高效液相法测定伊维菌素粉的含量

伊维菌素是从阿佛曼链霉素菌发酵产物分离的独特物质经化学修饰而制成。20世纪80年代中期的国外研究证实,伊维菌素对动物体内线虫和体表寄生虫均有显著驱杀效果。1994年美国默沙东药厂生产伊维菌素,年销售额达4.95万美元,列居当年世界动物保健品市场的10大产品榜首。由伊维菌素加一定辅料配制而成的伊维菌素粉,具有广谱、低毒、安全、适口性好、无刺激性及用法简便等特点。经临床试验证明,对驱杀畜禽肠道线虫,体表螨、虱、蜱效果良好,明显降低畜禽死亡率,增重迅速,提高饲料转化率和畜禽产品质量。但目前只收载过伊维菌素注射液含量的测定方法,伊维菌素粉剂尚无收载和报道。本法采     

伊维菌素在不同动物中安全性、药效学和药代动力学的差异性研究进展

伊维菌素是一种被广泛应用于多种畜禽线虫病和外寄生虫病防控的抗寄生虫药物。由于伊维菌素具有非常突出的优点,在不同种属动物上使用时,其安全性、药效学和药代动力学的差异更容易被人们忽略。忽略动物种属差异,可能会导致寄生虫病防治失败,甚至安全事故的发生。对伊维菌素在不同动物中的安全性、药效学和药代动力学差异做一综述,以期为伊维菌素的临床用药提供参考,保障伊维菌素在不同动物中用药的安全性和有效性。     

HPLC法测定伊维菌素-丙硫苯咪唑片中伊维菌素的含量

采用高效液相色谱法(HPLC)测定伊维菌素-丙硫苯咪唑片中伊维菌素的含量,结果表明,伊维菌素在20~100μg·mL-1范围内具有良好的线性关系(r=0.9999),平均回收率为99.7%,RSD=0.8%。因此,该法可用于伊维菌素-丙硫苯咪唑片中伊维菌素的含量测定。     

犬口服伊维菌素中毒的救治

伊维菌素属大环内酯类抗生素,是阿维菌素B1的衍生物,即伊维菌素H2B1a和伊维菌素H2B1b的混合物,它不溶于水,但有吸湿性,具有高效、广谱、口服吸收比皮下注射吸收     

伊维菌素小单室脂质体工艺配方优化及质量分析

为获得高包封率的伊维菌素小单室脂质体,本研究对其制备工艺进行了优化,并选取超声波频率、超声时间、卵磷脂与胆固醇质量比、伊维菌素与卵磷脂质量比各因素进行正交交互作用考察,同时利用反相高效液相色谱法对各工艺配方组合下伊维菌素小单室脂质体的包封率进行了测定。结果显示,伊维菌素小单室脂质体的制备最佳配方和工艺组合为超声波频率200 kHz,超声时间6 min,伊维菌素与大豆卵磷脂质量比为1:10。经过优化组合,得到了较高品质的伊维菌素小单室脂质体,平均载药量达到(92.35±0.61)%,药物品质优良,且制备工艺简单可行。     

伊维菌素HP-β-CD包合工艺的优化

本文采用L9(34)正交试验,以伊维菌素利用率和增容倍数为指标,优选出伊维菌素-羟丙基-β-环糊精包合工艺的最佳条件。主要参数:伊维菌素与羟丙基-β-环糊精的物质量之比1∶3,包合时间2 h,研磨温度55℃。羟丙基-β-环糊精研磨时间是影响伊维菌素包合效果的主要因素。本试验为伊维菌素新制剂开发和临床应用提供试验依据。     

5种伊维菌素注射液在家兔体内的比较药动学研究

试验旨在研究5种不同处方的伊维菌素注射液在家兔体内的比较药动学特征。50只健康家兔随机分为5组,通过单次给药剂量(5 mg/kg体重)皮下注射伊维菌素注射液,3P97药动学计算软件处理血浆药物浓度—时间数据。家兔皮下注射伊维菌素注射液属于一级吸收一室开放模型。自制伊维菌素注射液的:T_1/2(Ka)(8.10±3.68) h、T_1/2(Ke)(36.34±14.63) h、T_max (22.38±8.63) h、 C_max (354.01±57.75) ng/mL、 AUC (25843±3029) ng/(mL·h)。经SPSS统计学分析软件分析显示自制伊维菌素注射液的T_1/2(Ka)、T_1/2(Ke) 无显著性差异,但C_max 分析显示与C、D存在显著性差异(P<0.05),与A、B无显著性差异(P>0.05),但明显高于A、B的C_max。AUC平均值明显高于其余4种,说明自制伊维菌素注射液在家兔体内具有吸收好,消除快,生物利用度高等优点,临床可安全使用,具有更好的抗寄生虫作用。     

The effect of diethylene glycol monoethyl ether as a vehicle for topical delivery of ivermectin

The effect of diethylene glycol monoethyl ether (DGME; Transcutol) on the permeation of ivermectin, a broad-spectrum antiparasitic agent, through bovine skin was evaluated byin vitro permeation experiments followed by serial sectioning of the skin to assess the amount of ivermectin retained in the skin. Ivermectin permeation through bovine skin was enhanced by DGME and this enhancement was DGME-concentration-dependent. Permeation of ivermectin was effectively enhanced in vehicles with low proportions of DGME, but the magnitude of permeation enhancement decreased as the proportion of DGME increased. The permeation was accompanied by the formation of cutaneous depots of ivermectin. Furthermore, the data indicated that the flux and the cutaneous accumulation of ivermectin were sensitive to the concentration gradient of DGME across the skin. This suggested that ivermectin was permeating with DGME, in which it is very soluble. Hence, the enhancing mechanism involves solubilization of the ivermectin by DGME and the transport of DGME itself across the skin. Based on these results, DGME appears to be a potential vehicle for topical delivery of ivermectin by transport through the skin and through formation of cutaneous depots of ivermectin.Abbreviations DGME diethylene glycol monoethyl ether     

The efficacy of pour-on ivermectin in bison (Bison bison)

To test the effectiveness of pour-on ivermectin in parasitized bison, changes in fecal parasite egg counts after treatment with ivermectin injectable or pour-on preparations were compared to a negative control group. There was no difference between the two ivermectin groups, and both forms of ivermectin were effective in reducing fecal parasite egg counts in parasitized bison.     

Ketoconazole increases the plasma levels of ivermectin in sheep

The parasiticide ivermectin and the antifungal drug ketoconazole are drugs that interact with P-glycoprotein. We have tested the ability of ketoconazole at a clinical dose to modify the pharmacokinetics of ivermectin in sheep. Lacaune lambs were administered with a single oral dose of ivermectin alone at 0.2mg/kg (n=5) or in combination with a daily oral dose of ketoconazole (10mg/kg) given for 3 days before and 2 days after the ivermectin (n=5). The plasma kinetics of ivermectin and its metabolite were followed over 15 days by HPLC analysis. Co-administration of ketoconazole induced higher plasma concentrations of ivermectin, leading to a substantial increase in the overall exposure of the animals to the drug. Ketoconazole did not reduce the production of the main ivermectin metabolite but it may rather act by inhibiting P-glycoprotein, and thus increasing the absorption of ivermectin. The use of a P-gp reversing agent such as ketoconazole could be useful tool to optimize antiparasitic therapy in the face of the worldwide development of anthelmintic resistance.     

A pilot study of the efficacy of topical ivermectin against lungworm in young red deer (Cervus elaphus)

Three groups of ten 4-month-old red deer (Cervus elaphus) calves naturally infected with lungworm (Dictyocaulus viviparus) were treated with either oral ivermectin (200 microg/kg), topical (pour-on) ivermectin (500 microg/kg) or oral oxfendazole (5 mg/kg). Faecal larval counts for lungworm were undetectable or very low for 14 days after treatment with oxfendazole, 28 days after treatment with oral ivermectin and for 49 days after treatment with topical ivermectin. This pilot study suggests that the topical formulation of ivermectin was very effective against lungworm and had a more persistent action than the oral ivermectin formulation in young red deer.     

Detection of levamisole and ivermectin in organ samples from a dead collie.]

A collie, known for its breed-dependent adverse reaction to ivermectin, was without any clinical signs. The dog was prophylactically treated with 3 mg/kg KG (s.c.) of levamisole. Within 15 minutes, the dog showed convulsions, vomitus, and dyspnea, and perished 2.5 hours after injection of the drugs. The pathological findings were not informative as to the cause of death, and with regard to the adverse reactions, additional application of ivermectin was not excluded. Therefore, organ samples were submitted for toxicological analysis of both levamisole and ivermectin. For detection of levamisole and ivermectin, modified GC/MS and HPLC procedures were developed. Concentrations up to 535 micrograms levamisole and up to 26 ng ivermectin were found per g tissue. Both analytical methods are sensitive enough to detect these drugs after application of low doses. This study elucidates that combination of low-dosed ivermectin and levamisole is no recommendable means against adverse effects of ivermectin, with respect to collies. Moreover, the synergistic effects of ivermectin and levamisole suggests the same drug incompatibility in other dog breeds and animal species.     

Electroretinographic changes after intravenous lipid emulsion therapy in a dog and a foal with ivermectin toxicosis

This case report describes ivermectin‐induced blindness in a dog and a foal with normal ophthalmic fundic examinations and attenuated electroretinography (ERG). Subsequent recovery in ERG was noted following intravenous lipid emulsion (ILE) therapy. A dog and a foal were evaluated for ivermectin‐induced blindness. Clinical signs included dull mentation, absent pupillary light reflexes (PLRs), and absent menace on presentation. The animals had normal fundoscopic examinations; however, in both cases ERG was consistent with neurosensory retinal dysfunction. Following ILE therapy for ivermectin toxicosis, return of menace, PLRs, and normal mentation were noted, as was improvement in ERG and serum ivermectin levels. These are the first documented cases of ivermectin‐induced blindness in a dog and a foal with normal fundic examinations and attenuated ERG. ERG improved in both animals after ILE therapy. ERG may assist in the diagnosis of ivermectin toxicosis in dogs and horses. ILE therapy may hasten recovery in treatment of ivermectin‐induced blindness.     

Efficacy of ivermectin in the treatment of induced Parascaris equorum infection in pony foals

Eighteen pony foals inoculated with 1,500 +/- 109 infective Parascaris equorum eggs were given 0.02 ml of ivermectin vehicle (liquid)/kg of body weight, PO, (control); 0.2 mg of ivermectin paste/kg, PO; or 0.2 mg ivermectin liquid/kg, PO, on postinoculation day (PID) 28. Foals were euthanatized on PID 42, and the small intestinal contents were examined for P equorum larvae. The mean number of fourth-stage P equorum larvae in foals treated with ivermectin paste and liquid were 3.5 and 6, respectively. Significantly (P less than 0.01) higher mean numbers of larvae (1,250) were detected in foals treated with ivermectin vehicle. Larvae recovered from foals treated with ivermectin vehicle were of significantly (P less than 0.002) longer mean length than those from foals treated with ivermectin paste or liquid. Gross examination of lungs and liver revealed similar pathologic changes from the migration of P equorum in all foals. Adverse reaction to treatment was not observed.     

伊维菌素长效透皮剂和普通注射剂在家兔体内的药代动力学比较研究

为比较研究制备的伊维菌素长效透皮制剂与普通伊维菌素注射剂药物代谢及药效时间,本研究制备伊维菌素含量分别为0.5%、1.0%和1.5%的长效透皮制剂,采用高效液相色谱法检测不同药量相同体积伊维菌素长效透皮制剂和普通伊维菌素注射剂（1.0%）在家兔体内的药代动力学,并通过PKSolver药代动力学处理软件对数据进行分析。结果显示,0.5%、1.0%、1.5%伊维菌素长效透皮剂和1.0%普通注射剂吸收半衰期分别为0.81、0.52、1.02和0.12 d;达峰时间为1.55、0.97、1.62和0.42 d;峰浓度为47.36、72.02、115.30和99.53 ng/mL;消除半衰期为3.61、5.92、5.59和1.79 d;平均滞留时间为5.27、7.37、5.13和2.16 d;药时曲线面积为1 488.70、3 081.98、3 161.20和480.00 ng·d/mL,伊维菌素长效透皮剂体内维持有效药物浓度的时间长达35 d,普通注射剂仅为9 d。结果表明,伊维菌素长效透皮剂效果稳定,可进行更深入的研究。     

药物治疗獭兔螨病比较试验

为了探索联合用药对獭兔螨病的治疗效果,将50只确诊为患螨病的獭兔随机分为5组,每组10只,其中A组用伊维菌素治疗;B组用伊维菌素加螨净治疗;C组用伊维菌素加双甲脒治疗;D组用伊维菌素加复方桔皮素乙酰酯治疗;E组用伊维菌素加敌百虫治疗。结果显示,A组治愈率为60%,B组治愈率为80%,C组治愈率为90%,D组治愈率为90%,E组治愈率为70%,结果表明伊维菌素结合双甲脒与伊维菌素结合复方桔皮素乙酰酯治疗兔螨效果最佳。