毛细管电泳法测定一清颗粒中七种成分的含量

建立了毛细管电泳法测定一清颗粒中的7种有效成分--盐酸小檗碱、汉黄芩苷、汉黄芩素、大黄素、芦荟大黄素、大黄酚和大黄素甲醚.采用未涂层弹性融硅石英毛细管柱,盐酸小檗碱的测定:以盐酸雷尼替丁为内标,运行缓冲液为0.2 mol/L磷酸二氢钠溶液-无水乙醇(1:1,pH 5.5),分离电压21 kV,重力进样10 S(高度15 cm),检测波长265 nm.其他6组分的测定:以对乙酰氨基酚为内标,运行缓冲液为8%甲醇(pH 9.42,含25 mmol/L 硼砂、25 mmol/LSDS和4mmol/L磺丁基-β-环糊精),分离电压14 kV,重力进样5 s(高度15 cm),检测波长254 nm.7种成分分别在2.6～13、2～20、l～10、1.6～16、1.2～12、7.2～72和l～10 μg/ml浓度范围内线性关系良好,回收率分别为100.3%、102.7%、101.8%、102.0%、99.0%、100.0%、98.2%,脚均小于3.09%.     

Fast determination of paracetamol by using a very simple photometric flow-through sensing device

A simple flow-through UV optosensing device was developed for the determination of paracetamol based on its transient retention and concentration on a suitable active solid support (Sephadex QAE A-25 anion-exchange resin) packed in the flow cell and the continuous monitoring of its native absorbance on the solid phase at 264 nm. The sample was injected into a 0.08-M NaCl carrier stream at pH 11.0 by using a simple monochannel FIA manifold. After developing the analytical signal, paracetamol was desorbed from the solid support by the carrier solution itself. A very good linear response was found in the concentration range 0.5-8.0 microg ml(-1) with a RSD (%) of 1.24, a detection limit of 0.022 microg ml(-1) and a sampling rate of 40 h(-1). A strong increase in sensitivity as well as a very much higher selectivity were achieved as compared with the conventional flow injection method as a consequence of the separation of the analyte from the sample plug and its retention on the active solid support placed in the detection area. Applicability of the proposed sensor to direct determination of paracetamol in pharmaceuticals (to solve the sample being the only treatment) was successfully demonstrated.     

Determination of ephedrine, theophylline and phenobarbital in a tablet dosage form by capillary electrophoresis

A capillary electrophoresis method was developed to separate and quantitate ephedrine (ED), theophylline (TP) and phenobarbital (PB) in a tablet dosage form. Tablets were ground and extracted with methanol using ultrasonication. Aliquots of standard stock solution were hydrodynamically injected for 5 s at the anodic end. Separation was performed on a fused silica capillary (72 cm x 50 microm i.d.; 50 cm to detector) at an applied voltage of 20 kV with a phosphate run buffer (pH 8.0, 50 mM). Analysis was performed at ambient temperature (23+/-1 degrees C) and the total run time was 9 min with detection at 220 nm. Calibration curves were prepared for ED, TP and PB with methyl p-hydroxy benzoate as internal standard. For each analyte, the correlation coefficients were >0.999 (n = 4). The RSD% of ten replicate injections for each analyte were <1%. The method was applied to the quantitation of ED, TP and PB in a commercial tablet dosage form.     

Determination of triamterene by transitory retention in a continuous flow solid phase system with fluorimetric transduction

A rapid and simple flow-through solid phase espectrofluorimetric system (sensor) is described in this paper for the determination of the diuretic triamterene at ng ml(-1) level in physiological fluids and in pharmaceuticals. This sensor is based on the transitory retention of the analyte on the cationic ion-exchanger gel Sephadex SP C-25 placed into a quartz flow-cell in the detection zone itself of a spectrofluorimeter and the continuous monitorization of its intrinsic fluorescence. The spectrofluorimeter was tuned at 240 (excitation) and 440 nm (emission). A transitory signal was obtained because the carrier solution used also eluted the analyte from the sensing zone and no derivatization reactions were needed. Triamterene could be determined in the concentration ranges of 10-400 and 2.5-80 ng ml(-1) with detection limits of 0.95 and 0.17 ng ml(-1) for 300 and 1000 microl of sample volume, respectively. The relative standard deviations (RSD) for ten independent determinations and at three concentration levels of standards solutions were lower than 0.90 for 300 microl and 0.45 for 1000 microl. The RSDs for the determination of triamterene in serum samples and pharmaceuticals were lower than 3.3 and 2.6%, respectively. The method was satisfactorily applied to the determination of triamterene in human serum and pharmaceuticals.     

Integrated pervaporation/detection for the determination of fluoride in pharmaceuticals

A selective dynamic method for the determination of fluoride in pharmaceuticals based on the integration of pervaporation and potentiometric detection in a laboratory-made module is proposed. The analyte was continuously converted into volatile trimetylfluorosilane by reaction with hexamethyldisilazane, injected into a donor stream and accepted in a basic buffer solution after pervaporation. The method thus developed has a determination range between 1.5 and 200 mg l⁻¹, precision (expressed as R.S.D.) of 3.4%, and has been applied to the determination of fluoride in different pharmaceutical products, with yields ranging between 90.6 and 100.3%.     

A flow-through optosensing device with fluorimetric transduction for rapid and sensitive determination of dipyridamole in pharmaceuticals and human plasma

A flow-through optosensor with fluorimetric transduction has been prepared for the sensitive and selective determination of dipyridamole in aqueous solutions and biological fluids. The method is based on a monochannel flow-injection analysis system using Sephadex QAE A-25 resin, placed into a Hellma 176-QS fluorimetric flow-through cell, as an active sorbing substrate. The native fluorescence of dipyridamole fixed on the solid sorbent is continuously monitored at wavelengths of 305 and 490 nm for excitation and emission, respectively. After obtaining the maximum fluorescence intensity, the eluent solution (KH(2)PO(4)/NaOH buffer solution, c(T)=0.05 mol l(-1), pH 6.0) is allowed to reach the flow cell, the analyte is removed, and the resin support is regenerated. When an NaOH (10(-4) mol l(-1))/NaCl (0.1 mol l(-1)) solution is used as carrier solution, at a flow-rate of 1.56 ml min(-1), the sensor responds linearly in the measuring range of 10-500 microg l(-1) with a detection limit of 0.94 microg l(-1) and a throughput of 22 samples per hour (300 microl of sample volume). The relative standard deviation for ten independent determinations (200 microg l(-1)) is less than 0.82%. The method was satisfactorily applied to the determination of dipyridamole in pharmaceutical preparations and human plasma.     

Determination of mitoxantrone by flow injection analysis using an amperometric detector.

Mitoxantrone was determined by flow injection analysis using a flow cell modified in the laboratory and fitted with carbon paste as an amperometric detector. The sample solution (100 microliters, 5 x 10(-8)-1 x 10(-5) M) was injected into the carrier stream of 0.1 M perchloric acid (pH 1.12). Mitoxantrone was determined by oxidation at the carbon paste electrode (CPE) at +0.90 V. A 60-cm delay coil (0.5 mm i.d.) was incorporated just before the detector (a canal thin layer) and a flow rate of about 4 ml min-1 was used. The system was successfully applied to the determination of mitoxantrone in a pharmaceutical preparation; the method was fast and reproducible.     

Selective determination of pyridoxine in the presence of hydrosoluble vitamins using a continuous-flow solid phase sensing device with UV detection

A very simple, inexpensive and highly selective flow injection UV spectrophotometric method for the determination of vitamin B(6) is presented. The native absorbance of the analyte is continuously monitored at 290 nm when it is transiently retained on Sephadex SP C-25 cation exchanger gel beads placed in the detection area of a flow cell. The preconcentration on the active solid phase provides by itself a high increase in sensitivity compared with the same procedure carried out without a solid support. The analytical response is linear in the concentration ranges 1-10 and 2-20 microg ml(-1) using 600 and 1250 microl of sample, respectively. The R.S.D. (%) are 0.65 (600 microl) and 0.84 (1250 microl) and the detection limits 0.08 and 0.02 microg ml(-1), respectively. The procedure was successfully applied to the determination of vitamin B(6) in pharmaceuticals containing (among other active principles) hydrosoluble vitamins in much higher concentrations than that tolerated by the method if performed in aqueous solution. Nevertheless they were tolerated using the proposed sensor due to the selective retention of the analyte.     

Simultaneous determination of naphazoline,diphenhydramine and phenylephrine in nasal solutions by capillary electrophoresis

A capillary zone electrophoresis (CZE) method has been developed to separate and quantitate naphazoline (NAPH), dyphenhydramine (DIP) and phenylephrine (PHE) in nasal solutions. Samples were diluted 1:25 in ultrapure water and injected at the anodic end. A central composite design has been used to optimise the experimental conditions for a complete and fast separation of the active ingredients studied. Critical parameters such as voltage, pH and buffer concentration have been studied to evaluate how they affect responses such as resolution and migration times. Separation was performed on a silica capillary with 75 microm I.D. and 70 cm total length at an applied voltage of 17.7 kV with a phosphate run buffer of pH 3.72 and 0.063 mol l(-1). Calibration curves were prepared for NAPH, DIP and PHE. For each analyte, the correlation coefficients were >0.999 (n=15). The RSD% of six replicate injections for each analyte were reasonably good. The method was applied to the quantitation of the three components in a commercial dosage form. The proposed method has the advantage of needing a very simple sample pretreatment and being faster than a typical HPLC chromatographic method.     

Determination of penicillamine in pharmaceuticals and human plasma by capillary electrophoresis with in-column fiber optics light-emitting diode induced fluorescence detection

In this paper, a capillary electrophoresis (CE) system with in-column fiber optics light-emitting diode (LED) induced fluorescence detection was developed for the determination of penicillamine (PA). The influence of buffer concentration, buffer pH, applied voltage and injection time was systematically investigated. Optimum separation conditions were obtained with 10 mM borate buffer at pH 9.1, applied voltage 20 kV and 8 s hydrodynamic injection at 30 mbar. The detection system displayed linear dynamic range from 3.2 x 10(-7) to 4.8 x 10(-5) mol L(-1) with a correlation coefficient of 0.9991 and good repeatability (R.S.D.=2.46%). The method was applied to the determination of PA in commercial tablets and human plasma, which the recoveries of standard PA added to tablets and human plasma sample were found to be in the range of 96.26-102.68 and 91.10-99.35%, respectively. The proposed method is cheap, rapid, easy, and accurate, and can be successfully applied to the formulation analysis and bioanalysis.     

Development and validation of a capillary electrophoresis method for the determination of codeine, diphenhydramine, ephedrine and noscapine in pharmaceuticals

The present work describes a simple, accurate and rapid method for the separation and simultaneous determination of codeine, diphenhydramine, ephedrine and noscapine present in cough-cold syrup formulations by capillary zone electrophoresis. Factors affecting the separation were the buffer pH and concentration, applied voltage, and presence of additives. Separations were carried out in less than 10 min with a 20 mM sodium tetraborate buffer, pH 8.50. The carrier electrolyte gave baseline separation with good resolution, great reproducibility and accuracy. Calibration plots were linear over at least three orders of magnitude of analyte concentrations, the lower limits of detection being within the range 0.42-1.33 microg ml(-1). Detection was performed by UV absorbance at wavelengths of 205 and 250 nm. Quantification of the components in actual syrup formulations was calculated against the responses of freshly prepared external standard solutions. The method was validated and met all analysis requirements of quality assurance and quality control. The procedure was fast and reliable and commercial pharmaceuticals could be analyzed without prior sample clean-up procedure.     

Optimisation, validation and application of a capillary electrophoretic method for the determination of zafirlukast in pharmaceutical formulations

Zafirlukast is a selective and competitive orally administered inhibitor of the cysteinyl leukotrienes and currently indicated for the prophylaxis and treatment chronic asthma. A simple, rapid, reliable capillary zone electrophoresis method for the determination of ZAF in pharmaceutical formulations was developed and validated. The influence of buffer concentration, buffer pH, organic modifier, capillary temperature, applied voltage and injection time was systemically investigated in a fused silica capillary (i.d. 50 microm, total length 80.5 cm and effective length 72.0 cm). Optimum results were obtained with 50mM borate buffer at pH 8.50, capillary temperature 25 degrees C and applied voltage 30 kV. The samples were injected hydrodynamically for 3s at 50 mbar. Detection wavelength was set at 240 nm. Meloxicam was used as internal standard. The method was suitably validated with respect to linearity, limit of detection and quantification, accuracy, precision, selectivity, robustness and ruggedness. The linear calibration range was 2.00-80.00 microg mL(-1) and the limits of detection and quantification were 0.75 and 2.00 microg mL(-1) with R.S.D. of 3.88 and 2.75%, respectively. The proposed method was applied for the determination of ZAF in its pharmaceutical formulations. The results obtained from developed method were compared with a HPLC method reported in the literature and no significant difference was found statistically.     

Amperometric determination of dipyrone in pharmaceutical formulations with a flow cell containing gold electrodes from recordable compact discs.

A simple, rapid, and precise amperometric method for quantification of dipyrone in pharmaceutical formulations is presented. The proposed method permits determinations in the 10(-7) mol L(-1) of the analyte and enables 90 determinations h(-1), employing only 100 microL of sample per determination. This method is based on the direct quantification of dipyrone in many pharmaceutical products, avoiding cumbersome processes such as previous separations, solvent extraction, or sample filtration. This new procedure was applied to commercial pharmaceutical tablets, and the results obtained were in excellent agreement with the ones obtained by the classical iodometric method.     

Determination of glycosides and sugars in Moutan Cortex by capillary electrophoresis with electrochemical detection

A method based on capillary electrophoresis with electrochemical detection has been developed for the separation and determination of paeoniflorin, sucrose, paeonoside, glucose, and fructose in Moutan Cortex for the first time. Effects of several important factors such as the concentration of NaOH, separation voltage, injection time, and detection potential were investigated to acquire the optimum conditions. The detection electrode was a 300 microm diameter copper disc electrode at a working potential of +0.60 V (versus saturated calomel electrode (SCE)). The five analytes can be well-separated within 12 min in a 40 cm length fused silica capillary at a separation voltage of 12 kV in a 75 mM NaOH aqueous solution. The relation between peak current and analyte concentration was linear over about 3 orders of magnitude with detection limits (S/N = 3) ranging from 0.9 to 1.3 microM for all analytes. The proposed method has been successfully applied to monitor glycoside and sugar contents in the real plant samples with satisfactory assay results.     

A novel method for fast determination of ranitidine in its pharmaceutical formulations by fast continuous cyclic voltammetry

INTRODUCTION: A novel method for the determination of Ranitidine in flow injection systems was developed. METHODS: Some investigations were also done to find the effects of various parameters on the sensitivity of the method. The conditions producing optimal performance were a pH value of 2, a scan rate value of 100 V/s, accumulation potential of (-100) mV, and accumulation time of 0.4 s. Some of the advantages of the proposed method are as follows: the removal of oxygen from the test solution is not required any more, the detection limit of the method is sub-nanomolar and finally, the method is fast enough for determination of compounds in a wide variety of chromatographic methods. We also introduce a special computer based numerical method, for calculation of the analyte signal and noise reduction. After subtracting the background current from noise, the electrode response was calculated, based on partial and total charge exchanges at the electrode surface. The integration range of currents was set for all the potential scan ranges, including oxidation and reduction of the Au surface electrode, to obtain a sensitive determination. The waveform potential was continuously applied on an Au disk microelectrode (12.5 microm in radius). RESULTS: The detection limit of the method for Ranitidine was found to be 25 pg/ml. For 8 runs, the relative standard deviation of the method at 1.1 x 10(-8) M was 2.1%. DISCUSSION: The method was successfully applied for fast determination of Ranitidine in its pharmaceutical formulations. Being very simple, precise, accurate, time saving and economical this method has many advantages compared to all previously reported methods.     

Determination of piroxicam by solid-phase spectrophotometry in a continuous flow system.

A simple flow injection UV spectrophotometric method was developed for the determination of piroxicam. The method is based on its transient retention and concentration on Sephadex DEAE-A-25 anion-exchange gel beads packed in the flow cell and the continuous monitoring of its native absorbance on the solid phase at 354 nm. The sample was injected into a 0.1 M NaCl carrier stream at pH 9.5 by using a simple monochannel FIA manifold. When the analytical signal reached a maximum value, piroxicam was eluted from the solid support by means of a desorbing solution (0.2 M, pH 4.5). The response of the sensor was linear in the concentration range 0.5-10 microg ml(-1) with a R.S.D. (%) of 1.8, a detection limit (3 sigma criterion) of 0.1 microg ml(-1) and a sampling rate of 13 h(-1). Application to the analysis of pharmaceutical samples testifies to the utility of this sensor. The accuracy of the proposed method was better than 5%.     

盐酸肾上腺素注射液中S-对映体的测定及稳定性考察

目的:建立肾上腺素对映异构体中S-对映体的高效毛细管电泳检测方法。方法:采用未涂层熔融石英毛细管(50μm×42 cm,有效长度32 cm),以含13 mmol·L-1DM-β-CD pH 2.5的缓冲体系(含0.10 mol·L-1磷酸和0.07 mol·L-1三乙胺)为背景电解质溶液,在20 kV分离电压下,于214 nm波长处测定S-对映体。结果:肾上腺素R-对映体和S-对映体浓度分别在0.0026～0.1036 mg·mL-1范围内线性关系良好,相关系数分别为0.9995和0.9999(n=6);定量限分别为0.3和0.4μg·mL-1(S/N≥10),检测限分别为0.1μg·mL-1(S/N≥3)。结论:本方法灵敏度高,重复性好,可用于盐酸肾上腺素注射液中S-对映体的测定及稳定性研究。     

Copper carbonate as a solid-bed reactor for spectrophotometric determination of doxycycline and oxytetracycline in an unsegmented continuous flow assembly

The FIA—spectrophotometric determination of doxycycline was carried out by reaction of the drug with cupric ions entrapped in a polymeric material in a packed-bed reactor: the complex formed was then injected into a manifold with an alkaline solution as carrier. The developed colour was monitored at 395.0 nm. The method was applied to the determination of doxycycline in different pharmaceutical formulations. The calibration graph for doxycycline hyclate was linear over the range 10.0–80.0 mg ml⁻¹ (n = 8) with a relative standard deviation of 1.4% (at 25 mg ml⁻¹) and a sample throughput of 128 h⁻¹. The proposed procedure was also applied to the determination of oxytetracycline in pharmaceutical formulations.     

Drug therapy of metastasizing prostate carcinoma with special reference to the bioavailability of fosfestrol after oral administration

Prostata cancer is one of the most dangerous tumours occurring in the older man. No general accepted therapy has existed up to now. In this study we were engaged on the pharmacokinetics of fosfestrol (Honvan) after oral administration. Its active principle is E-diethylstilbestrol (E-DES), the main metabolite. 250-1600 ng/ml E-DES are measurable after 60-110 min in the plasma of 11 patients suffering from metastatic prostata cancer who have been administered 360 mg fosfestrol orally. This range is equivalent to E-DES concentrations in plasma of 1-4 x 10(-6) mol/l. Thus that E-DES concentration range (5 x 10(-6) mol/l) is nearly attained for a short time to the concentration which hinders the mitosis of human breast cancer cells. Surprisingly similar but not higher concentration - time courses may be measured after a bolus infusion of 360 mg fosfestrol (lasting 45 min). Furthermore, E-DES-glucuronide, E-DES-sulphate and the mixed E-DES-glucuronide-sulphate could be observed in plasma after oral administration. In spite of the high sensitivity of the analytical method (limit of detection for fosfestrol 0.1 micrograms/ml and for E-DES and its mono-conjugates 2-5 ng/ml) neither fosfestrol nor E-DES-monophosphate are detectable in plasma due to the biotransformation of fosfestrol, which is already metabolized by the enzymes of the gut wall. Both phosphates only exist in plasma after intravenous infusion. Further investigations are linked with the question if phase II-conjugates of E-DES can eventually be prodrugs delivering E-DES by cleavage of the ester bonds.     

Determination of active ingredients in Huangdan Yinchen Keli by CZE with amperometric detection

A simple, reliable and reproducible method, based on capillary zone electrophoresis with amperometric detection (CZE-AD), has been developed for simultaneous determination of five active ingredients in complicated traditional Chinese medicines including chlorogenic acid, caffeic acid, aloe-emodin, emodin and rhein. A carbon-disk electrode was used as working electrode. The optimal conditions of CZE detection were 30 mM borate solution (pH 9.5) as running buffer, 18 kV as separation voltage and 1.00 V (versus Ag/AgCl) as detection potential. There was excellent linearity between current response and analyte concentration over two orders of magnitude, while the limits of detection were 1.1 x 10(-7), 3.0 x 10(-7), 1.5 x 10(-7), 2.9 x 10(-7), 1.4 x 10(-6) mol/l for aloe-emodin, emodin, rhein, chlorogenic acid and caffeic acid, respectively (S/N = 3). The utility of this method was demonstrated by monitoring a kind of complicated Chinese medicine named Huangdan Yinchen Keli. Two samples manufactured by different companies were monitored with satisfactory results.