HPLC测定盐酸多西环素可溶性粉含量

采用高效液相色谱法(HPLC)测定盐酸多西环素可溶性粉中多西环素的含量,并对检验方法[1]进行复核验证.色谱柱 Waters Nova.pakR○C18( 3.9 mm×150 mm, 4 μm);以0.05 mol/L草酸铵溶液-二甲基甲酰胺-0.2 mol/L磷酸氢二铵溶液(65∶30∶5)(用氨试液调节pH值为8.0)为流动相;柱温35 ℃;检测波长280 nm;流速1.0 mL/min;进样量20 μL.多西环素进样浓度在4.0～144.0 μg/mL的范围内与峰面积呈良好的线性关系(r=1.000);样品的平均加样回收率(n=9)为98.5%,RSD为2.0%;完成了185批次样品的检验,检验结果准确可靠.该方法准确度高,重复性好,结果可靠,能够有效地检测盐酸多西环素可溶性粉的含量.     

Doxycycline levels in preocular tear film of horses following oral administration

Objective To determine the concentration of doxycycline in preocular tear film following oral administration in horses as a possible therapeutic modality for infectious and keratomalacic equine keratitis. Procedure Eight broodmares without ocular disease from a Thoroughbred breeding facility were included in this study. Each mare received 20 mg/kg of doxycycline by mouth once daily in the morning for five consecutive days. Tears were collected 1 h after doxycycline administration starting on day one of administration and continuing for 10 consecutive days. Doxycycline levels in the tears were measured using liquid chromatography with tandem mass spectrometric detection (LC-MS/MS). Results Doxycycline was present in the tears of each mare at low µg/mL levels with the highest concentration appearing on the third to fifth days (8.21–9.83 µg/mL). Doxycycline levels had fallen below quantifiable ranges by day 10. No systemic side-effects were noted in any of the horses included in this study. Conclusions Oral doxycycline is present in preocular tear film of normal horses with noninflamed eyes and may be useful as treatment in equine ulcerative keratomalacia. The oral dose listed was tolerated well by the horses in this study. The drug levels attained at 20 mg/kg once daily orally of doxycycline may aid in the treatment of corneal ulceration in horses, but further study is warranted.     

强力霉素对兔经皮腔内血管成形术后内膜增生的抑制作用

目的 探讨强力霉素对兔经皮血管腔内血管成形术(percutaneous transluminal angioplasty,PTA)后内膜增生的影响及其作用机制.方法 新西兰大白兔采用高脂饲料喂养制成动脉粥样硬化模型后,分为假手术组、单纯PTA组、3种剂量强力霉素组,每组6只.强力霉素组于术前2 d开始饮用强力霉素溶液,...     

强力霉素壳聚糖纳米粒冻干粉的体内外释药特性

分别采用紫外分光光度法和超高效液相色谱法研究强力霉素原料药与强力霉素壳聚糖纳米粒冻干粉的体内外释药特性。结果表明:强力霉素原料药在人工胃液、肠液和pH7.4磷酸缓冲液中的体外释放均可用零级动力学方程拟合,释放较快,在1h内能完全溶出;强力霉素壳聚糖纳米粒冻干粉具有显著的缓释特性,在各介质中的体外释放均可用双相动力学方程拟合,前期表现为快速释放,后期为缓慢释放,冻干粉在各介质中的释药速率从大到小依次为:pH2.0人工胃液>pH3.0人工胃液>pH4.0人工胃液>人工肠液>pH7.4磷酸盐缓冲液。强力霉素原料药包裹成强力霉素壳聚糖纳米粒冻干粉后,经(25±1)℃20mg/kg单剂量口灌,在斑点叉尾的药—时曲线由双峰变为单峰,在血浆中的血药峰浓度(Cmax)减小,峰值时间(Tmax)和消除半衰期(T1/2β)明显延长,药时曲线下面积(AUC)变大,是一种理想的强力霉素新剂型。     

江苏省畜禽养殖场水环境中四环类抗生素污染研究

2009年在江苏省范围内采集27个规模化养殖场排水口和周围环境水体样品53个,用高效液相色谱-三重四极杆质谱对其中的土霉素（OTC）、金霉素（CTC）、四环素（TC）和强力霉素（DOX）等四环素类抗生素污染进行了检测。结果显示,土霉素、金霉素、四环素和强力霉素在水体样品中的检出率分别为60.4%、60.4%、34.0%和17.0%,污染量分别在0.07～72.91、0.10～10.34、0.08～3.67μg·L-1和0.11～39.54μg·L-1之间,检出率以土霉素和四环素最高;猪养殖场中土霉素、四环素和强力霉素的污染量比牛和鸡场的要高,牛场中金霉素和强力霉素的污染量明显低于鸡场;从区域上看,苏南地区受到的污染明显高于苏北。     

Ocular penetration of oral doxycycline in the horse

OBJECTIVE: To investigate intraocular penetration of orally administered doxycycline in the normal equine eye and to compare intraocular and serum doxycycline concentrations. Procedures Six mares were administered doxycycline at 10 mg/kg every 12 h by nasogastric tube for 5 days. Blood, aqueous, and vitreous samples were collected on days 1 and 5. All samples were assayed for doxycycline concentrations. Aqueous and vitreous samples were also assayed for protein quantitation. RESULTS: Doxycycline was rapidly absorbed after the first dose (T(max) value of 1.42 +/- 1.28 h); and elimination of doxycycline occurred slowly (median t(1/2) = 10.88 h). Doxycycline could not be detected in the aqueous on days 1 and 5, nor could it be detected in the vitreous on day 1. On day 5, the mean vitreous doxycycline concentration was 0.17 +/- 0.04 microg/mL at 2 h after drug administration. CONCLUSIONS: Repeated oral administration of doxycycline in the horse resulted in steady state serum concentrations of < 1 microg/mL; however, it did not result in appreciable concentrations of drug in the aqueous and vitreous in normal eyes.     

液相色谱－串联质谱法测定鸡蛋中多西环素的残留量

采用液相色谱-串联质谱法测定鸡蛋中多西环素的残留量.用0.01 mol/L的乙二胺四乙酸二钠溶液和0.3%磷酸溶液为提取液,三氯乙酸溶液为蛋白沉淀剂,离心后上清液经HLB固相萃取柱净化、浓缩.色谱柱为Agilent C18柱(150 mm×2.1 mm i.d,5 μm);以0.1% 甲酸溶液、甲醇为梯度洗脱流动相.标准曲线的线性范围为0.01～0.5 μg/mL.经3种不同浓度回收率的测定,其回收率在79.7%～86.6%之间,RSD小于7.7%(n＝5).检测限为4 μg/kg.测定结果产蛋鸡用0.02%多西环素溶液饮水,连用5 d,投药量为每只鸡45.45 mg/d,在用药第3、4、5天,其鸡蛋中残留量分别为0.94、0.67、0.27 mg/kg,均高于国家规定的MRL 0.20 mg/kg;停药后,多西环素在鸡体内残留消除缓慢.     

Pharmacokinetic depletion phase of doxycycline in healthy and Mycoplasma gallisepticum‐infected chicken broilers after coadministration of enrofloxacin traces

The objective of this study was to investigate the influence of enrofloxacin (ENR) traces on doxycycline (DC) pharmacokinetic depletion phase parameters in plasma and lungs of healthy and Mycoplasma gallisepticum (MG)‐infected chicken broilers. The multiple‐dose oral administration of DC to chickens which were permanently exposed on ENR traces significantly increased concentration of DC in plasma and lung. It also prolonged the DC elimination time in both healthy and infected animals after final dose. The obtained result indicated that simultaneous administration of DC and ENR in chicken broilers therapy should be avoided.