反刍动物瘤胃缓控释制剂研究进展

瘤胃缓控释制剂多用于反刍动物抗胃肠道寄生虫或营养补充剂,国内外均有研究。本文综述了瘤胃缓控释制剂的机理及应用,以及存在的问题和发展前景。     

浅谈兽药缓控释制剂的研究进展

本文对缓控释制剂的特点、缓控释装置做了简要介绍,并概述了缓释丸制剂、控释塑囊、缓释凝胶剂、缓释微球、脂质体缓控释制剂、纳米粒缓控释制剂、溶液型注射缓控释剂、乳剂型注射缓控释剂等几种重要的缓释制剂,分析了目前缓控释制剂存在的几个主要问题,对其前景做了展望。     

缓控释技术的研究进展

结合临床应用对缓控释制剂的类型进行综述,主要介绍骨架缓控释技术、渗透泵技术、定位释放技术、生物黏附技术、脉冲释放技术在制剂中的应用发展。     

兽药缓控释制剂的研究进展

长效制剂由于其可以减少给药次数同时保证药效等一系列优点在兽药领域发展较快。综述了国内外兽药领域开发研制的多种缓控释制剂,包括缓释装置、新型的缓释剂型等。并对其制备、性能药物释放行为做了详尽的说明,并对兽药缓控释制剂未来的发展做了进一步的展望。     

兽药新剂型与新技术的应用与发展

系统阐述了兽药新剂型中的缓控释制剂、经皮制剂、脂质体制剂、微囊制剂、纳米混悬剂、亚微乳制剂,以及固体分散、包合、乳化等新技术在兽药领域的应用。     

反刍动物饲用尿素缓(控)释技术研究进展

尿素缓(控)释技术包括物理缓释法、化学缓释法、抑制脲酶活性法和近年来出现的包被尿素法。本文对几十年来关于饲用尿素缓(控)释方法进行了综述,指出物理方法中以糊化淀粉尿素和糖蜜尿素舔砖较为可行,但这两种方法并没有提高尿素氮的利用率;化学缓释法中以羟甲基脲最为可行;抑制脲酶活性法普遍存在瘤胃微生物对之产生适应性的问题;包被尿素法可以根据瘤胃微生物对氨气的需要进行控释,开发经济、无毒无害并可生物降解的包膜材料是今后研究的重点。不同生态区位瘤胃微生物对氨气的动态营养需要模式是进一步提高饲用尿素缓(控)释效果的理论基础。     

兽药长效制剂的国内外应用情况

<正>1.国外应用情况1.1口服长效制剂目前,国外研究的口服长效制剂主要为控释胶囊和缓释大丸剂。最早投放市场的是瘤胃巨丸剂PARATECT Bolus(辉瑞公司生产),是一种甲噻嘧     

Ivermectin缓控释制剂的研究进展

近年来 ,ivermectin(伊维菌素 ,IVM)缓、控释制剂广泛应用于动物寄生虫及多种疫病的防治 ,本文就其作用、制剂、优点、药物代谢动力学和可能带来的问题等方面进行了综述     

抗动物寄生虫药的长效丸制剂

长期以来,防治动物寄生虫病的主要手段是药物,而药物的普通剂型(口服用的散剂、片剂、注射剂、洗浴、喷洒用的液体制剂等)仅能一次性地杀死正在寄生的虫体,而无预防寄生虫感染作用,为提高防治效果,节省人力和药物,近10年来,已研制出长效、透皮吸收、舐食及具有引诱调味等不同功能的制剂。这里仅对长效丸制剂做以简介。1反刍动物口服瘤胃释放剂这类制剂大都是较大丸剂,可分普通缓释剂和控释剂。普通缓释剂是一次投服药丸后在瘤胃中连续不断释放药,开始放药量大,随着时间推移,药丸变小,放药量越来越少。控释剂又分连续放药型和脉冲放药型2种类…     

Ivermectin缓控释制剂的研究进展

近年来，ivermectin(伊维菌素，IVM）缓，控释制剂广泛应用于动物寄生早及多种疫病的防治，本文就其作用，制剂，优点，药物代谢动力学和可能带来的问题等方面进行了综述。     

Efficacy of ivermectin in injectable and oral paste formulations against eight-week-old Strongylus vulgaris larvae in ponies

A controlled test method was used to evaluate the efficacy of injectable micelle and oral paste formulations of ivermectin (22,23-dihydroavermectin B1) against 8-week-old Strongylus vulgaris larvae in experimentally infected pony foals. The dosage level of the drug in both formulations tested was 0.2 mg/kg. Ponies were euthanatized and necropsied 5 weeks after treatment. Based on the recovery of live vs dead S vulgaris from mesenteric arteries, both formulations were greater than 99% effective. Increased weight gains and marked reductions in the severity of arterial lesions were observed in treated ponies.     

兽药控/缓释剂的研究进展

本文系统地介绍了兽药控／缓释剂的特点、产生和国内外研究应用概况，分析了控／缓释剂亟待解决的问题，并对控／缓释剂的发展前景进行了展望。     

In vitro and in vivo evaluation of an in situ forming gel system for sustained delivery of Florfenicol

The objective of this study was to develop an injectable in situ forming gel system based on Poloxamer for sustained release of Florfenicol (FFC). The formulations were prepared containing certain amounts of Poloxamer 407 (P407) and Poloxamer 188 (P188) alone or with hydroxylpropyl methylcellulose (HPMC), sodium carboxymethyl cellulose (CMC‐Na), or polyvinyl pyrrolidone (PVP) as polymer additives. The optimal formulation was chosen according to in vitro parameters (gelation temperature, gelation time, pH value, viscosity, and in vitro release). Then the FFC in vivo pharmacokinetic character of the optimal formulation was investigated in dogs with a single dose of 50 mg/kg b.w. under s.c. injection. In vitro release studies, all formulations containing polymer additives had prolonged release time and decreased initial burst to some extent. The optimal formulation containing 0.15% HPMC showed a best sustained release profile for about 128 h with the lowest initial burst in vitro (<40% in 24 h). In vivo, the 20% FFC in situ forming gel provided prolonged drug release time within the therapeutic range for about 100 h, with stable plasma levels and elimination half‐life (t_1/2λz) nine times higher than the control formulation. In conclusion, in situ forming gel is an attractive alternative for FFC sustained release system.     

A preliminary study of pregnancy termination in the bitch with slow-release formulations of prostaglandin analogues

Forty-two beagle bitches at gestational ages from 4 to 35 days were treated with various formulations of the prostaglandin analogues fluprostenol and cloprostenol at doses from 10–40 μg/kg in an attempt to terminate pregnancy. Pregnancy was confirmed and the effect of treatment assessed by euthanasia and post-mortem examination to detect viable foetuses or resorbing implants twenty-one days after prostaglandin administration. Five of the bitches treated with an aqueous solution of cloprostenol by subcutaneous injection showed unacceptable side effects but both compounds in a slow release injectable formulation or impregnated into intravaginal devices had a luteolytic effect with only mild side effects in occasional bitches. Successful response to treatment in terms of sustained depression of plasma progesterone concentrations and pregnancy termination was 80 per cent at gestation stages of 25 days or over but only 27 per cent when given earlier in pregnancy. Mature follicles developed in two bitches which aborted following treatment at 14 days and returned to oestrus 10–14 days later. These preliminary findings show that slow-release formulations of fluprostenol and cloprostenol can cause complete luteolysis in the bitch.     

Comparison of febantel tablets and Vercom paste against gastrointestinal nematodes of dogs.

Thirty adult dogs with naturally acquired gastrointestinal nematode infections were assigned at random to ten replicates and treated daily for 3 days with either a combination febantel/praziquantel (Vercom) paste, febantel tablets or placebo tablets. Numbers of hookworm and whipworm eggs after treatment were reduced similarly for both drug formulations when compared with pretreatment egg counts, whereas these counts increased in the controls. Vercom paste reduced the hookworm egg count by 99.9% and the whipworm egg count by 99.6%. The febantel tablet decreased the hookworm egg count by 99.9% and the whipworm egg count by 100%. As determined at necropsy, the controlled test efficacy against adult hookworms and whipworms was similar for the Vercom paste and the febantel tablets. The controlled test efficacies of Vercom paste against Ancylostoma caninum, Ancylostoma braziliense, and Trichuris vulpis were, respectively, 99.7%, 100% and 95.8% and those of febantel tablets were 98.2%, 100% and 99.7%. These results indicate that the nematocidal efficacy of febantel against these nematodes remains unchanged in these two formulations. No adverse reactions to either febantel tablets or to Vercom paste were observed.     

Evaluation of the efficacy and safety of two formulations of pyrantel pamoate in cats

The efficacy of paste and granule formulations of pyrantel pamoate against concurrent infections of Toxocara cati and Ancylostoma tubaeforme in cats was examined in a controlled trial. Three groups of 8 cats received either no medication (controls) or pyrantel pamoate in paste or granule formulations at a dosage of 20 mg/kg of body weight. After administration of the paste formulation, fecal egg counts of A tubaeforme and T cati were decreased by 98.6 and 96.4%, respectively, and 100% of hookworms and 93.5% of ascarids were removed from the intestine. After administration of the granule formulation, fecal egg counts of A tubaeforme and T cati were decreased by 99.4 and 78.2%, respectively, and 100% of adult hookworms and 88.9% of ascarids were removed. All reductions of egg counts and worm numbers were significant (P less than 0.01). The clinical safety of pyrantel pamoate was evaluated in 4- to 6-week-old kittens. Three groups of 10 kittens received either no medication (controls) or pyrantel pamoate in paste or granule formulations at the rate of 100 mg/kg for 3 consecutive days. Adverse effects were not observed in young kittens following administration of the high dose of pyrantel pamoate.     

Veterinary drug bioequivalence determination

A bioequivalence trial is a statistically based comparison of two formulations to demonstrate with a controlled consumer (patient) risk that two formulated drug products are interchangeable. The basic assumption underlying a bioequivalence trial is that essentially the same plasma time-course leads to essentially the same effect allowing two formulations to be interchanged. Bioequivalence is generally assessed using kinetic end points and in practice, two formulations in which bioavailability parameters (rate and extent) differ by 20% or less, with a 90% degree of confidence, are considered to be bioequivalent. In this review, the design and evaluation of bioequivalence studies are presented with special attention given to scientific issues.     

缓控释微丸的研究进展

通过查阅国内外有关文献,对近年来缓控释微丸的辅料、制备方法、包衣技术及释药机理等的研究概况作一综述,并对其在兽药领域的发展前景进行了展望。