环丙沙星在BTR缓冲液中的紫外光谱性质研究与应用

研究了不同缓冲溶液 ,不同pH介质中环丙沙星的紫外光谱性质 ,提出在BrittonRobinson(BTR)缓冲溶液中为紫外分光光度法测定环丙沙星的最佳条件 .在吸收波长 2 77nm处 ,测得其表观摩尔吸收系数为 2 .6 3× 10 4L/mol.cm ,浓度在 3.0～ 2 3.0mg/L范围内 ,吸收度与浓度符合比尔定律 ,该法成功用于药物制剂中环丙沙星含量的测定 ,结果满意     

In vitro study of a HPγ-cyclodextrin grafted PET vascular prosthesis for application as anti-infectious drug delivery system

Hydroxypropyl-γ-cyclodextrin (HPγ-CD) was grafted onto woven polyester (PET) vascular prosthesis by using citric acid (CTR) as crosslinking agent. A polyCTR-HPγ CD polymer was physically fixed onto the PET fibers. An optimal compromise between fixation temperature and fixation time was found and a grafting rate of 6.7% was obtained. The study of the inclusion of ciprofloxacin (CFX) and HPγ-CD was evidenced by using spectrophotometry. Sorption tests also showed that modified prosthesis could adsorb 5 times more CFX than the control. Biological tests revealed proliferation rates of human pulmonary micro-vascular endothelial cells (HPMEC) of 73 and 48% on virgin and modified prostheses respectively. We demonstrated that this was rather due to the increase of surface roughness of the fibers after their modification than to a toxic effect the polyCTR-HPγCD polymer coating. Prostheses samples modified with HPγCD and impregnated with CFX stayed up to 24 h in blood plasma. At various moments some aliquots were withdrawn from the medium and a positive antibacterial activity against Staphylococcus epidermidis was observed within the 24 h period for the grafted sample, whilst that of the virgin one had disappeared within 4 h. So, cyclodextrin coating of vascular prostheses may be suitable for the controlled release of CFX, and thus should help to the prevention of post surgery complications.     

Spectral properties of Eu(III) compound with antibacterial agent ciprofloxacin (cfqH). Crystal structure of [Eu(cfqH)(cfq)(H2O)4]Cl2 · 4.55H2O

A novel europium complex of fluoroquinolone ciprofloxacin (cfqH) with formula [Eu(cfqH)(cfq)(H₂O)₄]Cl₂ · 4.55H₂O (1) was synthesized and its crystal structure determined by X-ray crystallography. The coordination number of europium is eight and in this structure two bidentate, O,O-bonded quinolone molecules and four aqua ligands are coordinated to the metal. One molecule of quinolone is anionic whereas the other is zwitterionic. Additionally, two chloride ions are also present in the structure to compensate the charge of the europium(III) whilst disordered solvent water molecules too are present. The spectral properties (IR, Raman, luminescence) of compound 1 were studied. Analysis of the Stark structure of the luminescence spectra was carried out and the scheme of the electronically excited states and photophysical processes of compound 1 was arranged. The spectral properties show that europium–ciprofloxacin complexes could be suitable for various applications based on their solution-state stability as measured by ¹H and ¹⁹F NMR.     

Potentiometric Determination of Ciprofloxacin in Physiological Fluids Using Carbon Paste and Nano‐Composite Carbon Paste Electrodes

Nano‐composite carbon paste and simple carbon paste based potentiometric sensors were constructed and used for determination of ciprofloxacin at different pH values. Sensors were formulated utilizing graphite, suitable plasticizer, cirprofloxacinium‐phosphotungstate, as well as a highly lipophilic cation‐exchanger, sodium tetrakis(trifluoromethyl)phenyl borate. Effect of the incorporation of multi‐walled carbon nanotubes (MWCNTs) on the response characteristics of the prepared sensors was investigated. Results obtained were compared to that of a PVC‐sensor contains only the cation‐exchanger. In addition, the effect of solutions pH on the response characteristics was also studied; at pH 4.1, the slopes of bare carbon paste and MWCNTs‐based sensors were 55.7 and 66.6 mV/conc.decade in a concentration range of 10⁻²‐10⁻⁵ M with detection limits of 1.0x10⁻⁵ and 7.9x10⁻⁶ M, respectively. Although both sensors exhibited super‐Nernstian slopes at pH 2.0, the selectivity was improved compared to that measured at pH 4.1. Optimized sensors were successfully applied for the determination of ciprofloxacin in its pure form, pharmaceutical preparations, as well as spiked urine and serum samples, with high recovery.     

Modeling nonbilinear total synchronous fluorescence data matrices with a novel adapted partial least squares method

A new residual modeling algorithm for nonbilinear data is presented, namely unfolded partial least squares with interference modeling of non bilinear data by multivariate curve resolution by alternating least squares (U-PLS/IMNB/MCR-ALS). Nonbilinearity represents a challenging data structure problem to achieve analyte quantitation from second-order data in the presence of uncalibrated components. Total synchronous fluorescence spectroscopy (TSFS) generates matrices which constitute a typical example of this kind of data. Although the nonbilinear profile of the interferent can be achieved by modeling TSFS data with unfolded partial least squares with residual bilinearization (U-PLS/RBL), an extremely large number of RBL factors has to be considered. Simulated data show that the new model can conveniently handle the studied analytical problem with better performance than PARAFAC, U-PLS/RBL and MCR-ALS, the latter modeling the unfolded data. Besides, one example involving TSFS real matrices illustrates the ability of the new method to handle experimental data, which consists in the determination of ciprofloxacin in the presence of norfloxacin as interferent in water samples.     

Nano engineered biodegradable capsules for the encapsulation and kinetic release studies of ciprofloxacin hydrochloride

Polyelectrolyte based nano and micro capsules have been extensively studied as promising drug carrier in recent years. Natural degradable capsules have received great deal of attention due to their fascinating structural and morphological characteristics, biocompatibility, sustained and targeted-release capabilities. In this work, chitosan - dextran sulphate nano capsules were prepared via Layer-by-Layer (L-b-L) technique using sacrificial template for drug delivery applications. The loading and in vitro release studies were performed using ciprofloxacin hydrochloride as a model drug. The release media used in the study are plain water and Phosphate Buffered Saline (PBS). The optimum drug load was 389 ​μg, at a loading pH of 2.1 and a temperature of 25 ​°C for 50 ​min encapsulation time. The drug loaded capsules exhibited a slow and sustained release up to 24 ​h and the maximum release rate was obtained at pH 1.2 in water and pH 7.4 in PBS. Least amount of drug release occurred at pH 5.0 in both the release media. The amounts of drug release in water at pH 1.2, pH 5.0 and pH 7.4 are 309 ​μg, 163 ​μg and 251 ​μg respectively where as the corresponding values in the case of PBS (at pH 1.2, pH 5.0 and pH 7.4) are 236 ​μg, 198 ​μg and 251 ​μg respectively. Two different models namely, Ritger - Peppas and Higuchi models were chosen to study the release kinetics behaviour of ciprofloxacin hydrochloride. The prepared bio-degradable capsules had potential as drug carrier for targeting antibacterial drugs with diverse functionality.     

环丙氟沙星荧光探针对小牛胸腺DNA相互作用的研究

使用紫外和荧光光谱法研究了环丙氟沙星(CIF)和小牛胸腺DNA(ctDNA)之间的相互作用。在pH 7.0磷酸盐缓冲液中,CIF在270 nm激发和在420 nm处有很强的荧光发射。它们间的沟槽作用导致小牛胸腺ctDNA对CIF的荧光存在着很强的猝灭作用,猝灭常数为2.64×104 mol-1L(25 ℃)。利用ctDNA对CIF的荧光猝灭作用建立了核酸测定的新方法,线性范围为80 nmol·L-1～45 μmol·L-1,对25 μmol·L-1ctDNA的相对标准偏差为4.2％。     

Simultaneous determination of enrofloxacin and its primary metabolite, ciprofloxacin, in chicken tissues

Summary An HPLC method with fluorescence detection is presented for the analysis of enrofloxcin (ENR) and ciprofloxacin (CIP) in chicken tissue using sarafloxacin (SAR) as internal standard. Tissue sample preparations were carried out by adding a phosphate buffer (pH 7.4, 0.1 M), followed by extraction with trichloromethane. Fluoroquinolones were separated on a reversed-phase column with a mobile phase of aqueous phosphate buffer-acetonitrile (80:20). The concentrations of CIP, ENR and SAR eluted off the column, with retention times of 2.28, 3.30 and 4.40, respectively, were monitored by fluorescence detection atλ _ex 338 andλ _em 425 nm. The detection limit was 32 ng g⁻¹ for CIP and 10 ng g⁻¹ for ENR. The standard curves were linearly related to concentration in the range of 1 to 2000 ng g⁻¹. Recovery was determinated as 91.3% and 78.3% for ENR and CIP, respectively. The measurement of the tissue levels of ENR and CIP in the chicken after oral administration confirmed the utility of the proposed analytical methodology.     

同步-导数荧光光谱法直接测定人体尿液中的盐酸环丙沙星的方法研究

研究了人体尿液中环丙沙星的荧光性质。通过控制体系中的pH值,消除了背景干扰,据此建立了同步－导数荧光光谱法直接测定人体尿液中环丙沙星含量的新方法。其线性范围为1．3－33．1ng/L,回收率99％－104％,相对标准偏差2．0％－2．4％。     

表面活性剂敏化稀土荧光探针对环丙沙星药物的测定研究

稀土铽离子能与环丙沙星形成络合物,并发射铽离子的特征荧光,加入表面活性剂SDBS能大大增强体系的荧光强度,由此建立了表面活性剂敏化的铽离子荧光探针测定环丙沙星的方法。用1 cm 石英比色池在激发波长为300 nm, 发射波长为545 nm处测定其荧光强度。在最佳测试条件为pH=8.0～8.5, Tb3+ 浓度为5.0×10-5 mol·L-1, SDBS浓度为8.0×10-4 mol·L-1时,环丙沙星的浓度与体系的荧光强度呈线性关系,线性范围为2.0×10-8 mol·L-1～2.5×10-6 mol·L-1, 相关系数为0.999 6,检出限为4.0×10-9 mol·L-1。该法可用于不同剂型环丙沙星药物的测定。