氟苯尼考纳米结晶的制备及其药剂学性质的考察

目的 增加氟苯尼考(FF) 的水溶性，制备氟苯尼考纳米结晶(FF-NC) 并对其药剂学性质进行体外评价。方法 采 用微型化介质研磨法，以西林瓶为研磨室，氧化锆珠子为研磨介质，磁力搅拌器为动力装置制备FF-NC，以粒径和多分散系数 (PDI) 为指标，正交试验得到的优化处方及工艺参数，进一步放大处方，采用喷雾干燥法固化FF-NC，以差式扫描量热分析，X 射线衍射分析，傅里叶红外光谱分析对所得纳米结晶进行表征，并考察其饱和溶解度及体外累积溶出度。结果 正交试验最优 处方制备得到的FF-NC，其粒径为(189.6±3.44)nm，PDI 为(0.192±0.021)；等比例放大研磨固化，复溶后FF-NC 粒径与喷雾干燥 前基本相同；X 射线衍射图谱和差式扫描量热分析结果均表明氟苯尼考制备成纳米结晶后呈无定型状态；饱和溶解度试验及体 外溶出结果表明制备的FF-NC 的饱和溶解度和体外累积溶出度明显高于FF 原粉。结论 微型化介质研磨法为FF-NC 制备工艺 的筛选提供了简单有效的途径，为放大化制备提供了依据，制备得到的FF-NC 速释、高效，值得进一步研究。     

Immunosuppressive Activity of Florfenicol on the Immune Responses in Mice

Florfenicol is a new type of broad-spectrum antibacterial that has been used in veterinary clinics. It shows immunosuppressive activity on the immune responses to ovalbumin (OVA) in mice. In the present study, florfenicol suppressed lipopolysaccharide (LPS)-stimulated splenocyte proliferation in a concentration-dependent manner in vitro and in vivo. BALB/c mice were immunized subcutaneously with OVA on days 1 and 4. Following the second immunization, mice were treated with a single daily oral dose of florfenicol (50, 100, and 200 mg/kg) for 10 consecutive days. On day 14, blood samples were collected to analyze OVA-specific IgG, IgG1, and IgG2b antibodies, and splenocytes were harvested to assess lymphocyte proliferation, CD3⁺ T and CD19⁺ B lymphocyte subsets. The results presented here demonstrate that florfenicol not only significantly suppressed Con A-, LPS- and OVA-induced splenocyte proliferation but also decreased the percentage of CD19⁺ B cells in a dose-dependent manner and suppressed CD3⁺ T cell at high doses. Moreover, OVA-specific IgG, IgG1 and IgG2b titers in OVA-immunized mice were reduced by florfenicol. These results suggest that florfenicol could suppress humoral and cellular immune responses in mice.     

In situ Formed Implants,Based on PLGA and Eudragit Blends,for Novel Florfenicol Controlled Release Formulations

Drug controlled release technologies (DCRTs) represent an opportunity for designing new therapies. Main objectives are dose number optimization and secondary effects reduction to improve the level of patient/client acceptance. The present work studies DCRTs based in blended polymeric implants for single dose and long-term therapies of florfenicol (FF), a broad spectrum antibiotic. Polymers used were PLGA and Eudragit E100/S100 types. Eudragit/PLGA and FF/PLGA ratios were the main studied factors in terms of encapsulation efficiencies (EEs) and drug release profiles. In addition, morphological and physicochemical characterization were carried out. EEs were of 50–100% depending on formulation composition, and the FF releasing rate was increased or diminished when E100 or S100 were added, respectively. PLGA hydrolytic cleavage products possibly affect Eudragit solubility and matrix stability. Different mathematical models were used for better understanding and simulating release processes. Implants maintained the antimicrobial activity against Pseudomonas aeruginosa up to 12 days on agar plates. The developed DCRTs represents a suitable alternative for florfenicol long-term therapies.     

HPLC法对氟尼康中盐酸多西环素及氟苯尼考含量的测定

目的：建立了同时检测药物氟尼康中盐酸多西环素、氟苯尼考的高效液相色谱检测法。方法：采用Hyrmrsil-ODS2（4．6mm×250mm,5μm）色谱柱,流动相为乙腈：甲醇：磷酸二氢铵（0．1mol／L）=10：11：29,pH=3．50,检测波长为254nm,流速为1ml／min。结果：实现了氟尼康中盐酸多西环素、氟苯尼考的较好分离;盐酸多西环素在6．25。200．00μg/ml范围内线性关系良好,r=0．9994,平均回收率为99．29％,RSD为0．51％（n=3）;氟苯尼考在6．25～250．00μg／ml范围内线性关系良好,r=0．9999,平均回收率为98．87％,RSD为0．32％（n=3）。结论：该方法快速简便,灵敏度高,重现性好,可作为药物氟尼康质量标准的测定方法。     

On-line molecular imprinted solid-phase extraction flow-injection fluorescence sensor for determination of florfenicol in animal tissues

A simple and convenient on-line molecular imprinted solid-phase extraction flow-injection fluorescence sensor was developed in this study. Florfenicol (FF)-imprinted polymer was prepared by self-assembly with acrylamide (AM) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as cross-linker. The binding characteristics of the imprinted polymer to florfenicol were evaluated by equilibrium binding experiments, and the morphology of the imprinted polymer was studied by scanning electron microscope (SEM). Fluorescence intensity of 3-p-nitrylphenyl-5-(2′-sulfonophenylazo) rhodanine (4NRASP) and bovine serum albumin (BSA) was inhibited by FF. Under optimum conditions the intensity of fluorescence shows a linear relationship with the concentration of FF over the range of 1.2 × 10⁻⁶ to 2.6 × 10⁻⁵ g mL⁻¹ with a regression equation of ΔI = 23.54 + 17.86c (c 10⁻⁶ g mL⁻¹) (r = 0.9965, n = 6). The low detection limit of FF was found to be 3.4 × 10⁻⁷ g mL⁻¹ according to 11 parallel determinations for the blank solution. The relative standard deviation for the determination of 2.0 × 10⁻⁶ g mL⁻¹ FF solution was 3.5% (n = 11). This proposed sensor could be satisfactorily applied to the determination of FF in liver and meat samples.     

Coamorphous System of Florfenicol-Oxymatrine for Improving the Solubility and Dissolution Rate of Florfenicol: Preparation,Characterization and Molecular Dynamics Simulation

Coamorphous system has proved to be an effective approach to improve the solubility of BCSⅡ drugs. Florfenicol (FF) is a widely used veterinary antibiotic but has poor aqueous solubility. Therefore, the coamorphous system of florfenicol and oxymatrine (OMT) formulated at 1:1 and 1:2 M ratios were prepared by using solvent evaporation, followed by a series of characterization in terms of PXRD, DSC, FTIR and Raman spectroscopy. It was found that FF and OMT are miscible according to Hansen solubility parameters. The molecular electrostatic potential (MEP) and radial distribution function (RDF) analysis demonstrated the possible hydrogen bond interaction in coamorphous system, which was confirmed by FTIR and Raman spectra. The coamorphous FF-OMT (1:1) maintained stability for 60 days at 25 °C/0% RH and 30 days at 40 °C/75% RH, which may be attributed to better molecular miscibility of FF and OMT and the strong hydrogen bond of O–H (FF)?O–N (OMT) and N–H (FF)?O–N (OMT). In addition, the apparent solubility and permeability, dissolution and intrinsic dissolution rate (IDR) of the acquired coamorphous solids were obviously increased compared with crystalline FF. In conclusion, a drug-drug coamorphous formulation can be applied to improve the solubility and dissolution of crystalline FF.     

Development of an ultrasensitive ic-ELISA and immunochromatographic strip assay for the simultaneous detection of florfenicol and thiamphenicol in eggs

An ultrasensitive monoclonal antibody-based gold nanoparticle immunochromatographic strip assay and indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) were developed to detect florfenicol (FF) and thiamphenicol (TAP) in egg samples. The ic-ELISA, with optimized pH, methanol content and sodium chloride content, exhibited an IC₅₀ value of 0.2?ng/mL for FF and 0.27?ng/mL for TAP, with the working range of 0.05–0.77 and 0.05–1.42?ng/mL, respectively. The optimized ic-ELISA showed negligible cross-reactivity with other phenols and broad-spectrum antibiotics. The recoveries in egg samples using the ic-ELISA ranged from 84% to 115% with a coefficient of variation of less than 5%. Based on this monoclonal antibody, a rapid and ultrasensitive immunochromatographic strip assay was developed with a cutoff value of 1?ng/mL for FF and TAP. Our results indicated that both developed methods were highly useful for screening FF and TAP in eggs.     

Comparative evaluation between capillary electrophoresis and high-performance liquid chromatography for the analysis of florfenicol in plasma

A capillary electrophoresis (CE) and a reversed phase high-performance liquid chromatography (RP-HPLC) method with UV detection have been developed for florfenicol analysis in plasma samples. The suitabilities of both methods for quantitative determination of florfenicol were approved through validation specification, such as linearity, precision, selectivity, accuracy, limit of detection and quantification. The capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC) assay were compared by analyzing a series of plasma samples containing florfenicol in different concentrations using the two methods. The extraction procedure is simple and no gradient elution or derivatization is required. Furthermore, the analysis time of the CE method is two times shorter than the respective parameter in HPLC and solvent consumptions is considerably lower. The calibration curve were linear to at least 0.05–10 μg/ml (r = 0.9998) and 0.1–10 μg/ml (r = 0.9998) for CE and HPLC, respectively. The separation efficiency are good for both methods. The detection limits for florfenicol were 0.015 μg/ml with CE and 0.03 μg/ml with HPLC and CE method gave lower value, even though UV detector was applied in the both cases. The both methods were selective, robust and reliable quantification of florfenicol and can be useful for clinical and biomedical investigations.     

星点设计-效应面法优化氟苯尼考缓释微球制备工艺

目的 优化复凝聚法制备氟苯尼考缓释微球工艺.方法 以复凝聚法制备微球,以粒径、包封率的总评“归一值”为评价指标,采用星点设计,考察囊材(明胶、阿拉伯胶)浓度、成囊pH、搅拌速度撒三因素对制备微球的影响,对结果进行二项式拟合,效应面法选取最佳工艺条件,优化工艺后制得的微球在人工体液中进行体外释放.结果 最佳工艺条件为囊材浓度2.2％、成囊pH3.9、搅拌速度450r/min;制得的微球圆整均一,粒径50μm左右,包封率51.80％,载药量可达14.29％;制得的微球在Hank′s人工模拟体液中有良好的缓释特征.结论 优化制备工艺条件下制得的微球外形良好载药量较大,缓释效果好.     

顶空毛细管气相色谱法测定氟苯尼考中残留溶剂

目的建立顶空毛细管气相色谱法测定氟苯尼考中残留溶剂的方法。方法以氮气为载气,用氩火焰离子化检测器（FID）检测,色谱柱为DB-624毛细管柱,柱温为程序升温,对氟苯尼考中甲醇、乙醇、异丙醇、二氯甲烷有机溶剂的残留状况进行检测。结果在实验条件下,甲醇、乙醇、异丙醇、二氯甲烷回收率分别为103．9％、99．3％、102．3％、95．4％,精密度分别为2．2％、2．1％、2．1％、2．4％。结论方法灵敏、准确,可用于氟苯尼考生产过程及成品的质量监控。。