Simultaneous Determination of Rosiglitazone and Metformin in Pharmaceutical Preparations by LC

In the present study, a novel, fast and simple liquid chromatographic method was developed and validated for the simultaneous determination of rosiglitazone and metformin in pharmaceutical preparations. The separation was achieved on a phenyl column (250 × 4.6 mm i.d., 5 μm) using a mobile phase composed of acetonitrile:10.0 mM phosphate buffer pH 5.5 (70:30, v/v). The flow rate was 1 mL min⁻¹. UV detection was performed at 245 nm and verapamil was used as internal standard. The developed method was validated in terms of stability, specificity, sensitivity, linearity, accuracy, precision and robustness. The limit of quantification was 0.02 μg mL⁻¹ for both drugs. The method developed was successfully applied to the simultaneous determination of rosiglitazone and metformin in pharmaceutical preparations. The results were compared to two methods reported in the literature and no significant difference was found statistically.     

Performance Evaluation of Charged Aerosol and Evaporative Light Scattering Detection for the Determination of Ginsenosides by LC

A sensitive LC-CAD method was developed for simultaneous determination of seven major triterpenoid saponins, namely ginsenosides Rg₁, Re, Rb₁, Rc, Rb₂, Rb₃ and Rd in Panax ginseng C. A. Meyer, a commonly used traditional Chinese medicine. This CAD method was evaluated in sensitivity, linearity and reproducibility compared to ELSD and UV. It was found the developed method has improved sensitivity, linearity and reproducibility compared to ELSD. This method was successfully applied to analyze the ginsenosides in ten samples of Panax ginseng. The validation results indicated that the improved method can be utilized as another approach for quality control of P. ginseng.     

硫酸沙丁胺醇的流动注射化学发光法测定

基于硫酸沙丁胺醇对N—溴代丁二酰亚胺—荧光素化学发光体系的强烈抑制作用，建立了硫酸沙丁胺醇的化学发光抑制分析法，详细研究了影响化学发光强度的因素，并探讨了抑制化学发光可能的机理；化学发光信号的降低值ΔI与硫酸沙丁胺醇的质量浓度在0．08—10mg／L范围内呈线性关系，方法的检出限(3σ)为0．026mg/L，对0．3mg/l的硫酸沙丁胺醇进行了11次平行测定，相对标准偏差为3．0％；将该法用于硫酸舒喘灵片中硫酸沙丁胺醇的定量分析，结果令人满意。     

Determination of Phenolic Acids in Danshen Preparations by LC with Chemiluminescence Detection

A simple and sensitive method has been developed for the simultaneous determination of eight phenolic acids in Danshen preparations based on liquid chromatography with chemiluminescence detection. Chemiluminescence parameters including flow rate, buffer pH, the concentration of luminescent and reactive solutions, were optimized. The analytical performance of the optimized luminol-H₂O₂ detection was compared with those of luminol-pyrogallol and UV detection. Under the optimized conditions, the method was validated with respect to linearity, precision, limits of detection and quantification. The method offers an attractive alternative to be used to evaluate the quality of Danshen preparations.     

Simultaneous Determination of Enalapril and Losartan in Pharmaceutical Preparations by UV Spectrophotometry and LC

The simultaneous determination of enalapril (Ena) and losartan (Los) in solid dosage forms were done by two methods. The first method involves spectrophotometric determination using the simultaneous equation method at 222 and 250 nm for Ena and Los, respectively. The second method involved an RP-LC method of analysis using methanol:water:acetonitrile (45:35:20% v/v) as the mobile phase. Both methods were satisfactorily validated as per ICH guidelines.     

Determination of Boanmycin in Pharmaceutical Preparations by a Simple and Rapid Ion-pair LC Method

An ion-pair HPLC method with UV detection is described for the determination of boanmycin in freeze-dried pharmaceutical preparations. Chromatographic separation was achieved on a 5 μm Agilent Eclipse XDB-C₁₈ column (150 × 4.6 mm). The mobile phase contained methanol, acetonitrile, 055 M sodium hexanesulfonate and 0.08 M acetic acid in water. UV detection was at 291 nm. The assay was validated over a linear concentration range from 0.05 to 120 μg mL^?1. The method was applied to determine the content of BAM in freeze-dried powders.     

在线固相萃取法结合电雾式检测器测定黄芪及其复方中黄芪甲苷的含量

采用在线固相萃取高效液相色谱法,结合电雾式检测器,建立了快速测定黄芪及其复方中黄芪甲苷的方法。采用Acclaim Polar AdvantageⅡC18(50 mm×4.6 mm,3μm)为在线净化柱,以双三元液相色谱的右泵作为上样净化泵,甲醇-水为流动相,梯度洗脱,进行富集和净化;采用Acclaim C18(150 mm×4.6 mm,5μm)为分析柱,以双三元液相色谱的左泵作为分析泵,乙腈-水作为流动相,等度洗脱,流速为1.0 mL/min,采用中心切割的方式将目标物从在线净化柱转移至分析柱中。电雾式检测器( CAD)的雾化器温度为30℃;氮气压力为241.3 kPa。黄芪甲苷在药材及复方基质中获得较好分离,黄芪甲苷在4.0~80 mg/L范围内,相关系数r=0.9998,平均回收率为97.6％。实验表明,本方法快速、简便,专属性、重现性较好,测定结果可靠,可应用于黄芪及其复方中黄芪甲苷含量的检测。     

Strategies for the Analysis of Pharmaceutical Cocrystals Using HPLC with Charged Aerosol Detection

Several active pharmaceutical ingredients are currently being developed as pharmaceutical cocrystals as these systems often have superior properties compared to traditional pharmaceutical forms. Pharmaceutical cocrystal formers typically used are polar, small molecule acids or bases which often lack a UV chromophore. Their polar nature results in almost no reversed phase retention and their detection typically cannot be done with UV. Here we discuss approaches for the analysis of pharmaceutical cocrystals using HPLC columns designed for polar retention, ion pairing chromatography (IPC), and hydrophilic interaction chromatography (HILIC) using model cocrystal formers. Corona charged aerosol detection (CAD) was used to monitor the cocrystal formers. l-alanine was used as a model basic cocrystal former, and succinic acid and glutaric acid were used as model acidic cocrystal formers. The acidic cocrystal formers were adequately retained on a C18 column. Heptafluorobutyric acid was used as the ion-pairing reagent for l-alanine as it was unretained without the ion-pairing reagent. HILIC, a newer approach for polar compound retention, was also investigated. Using the HILIC mode, all three model cocrystal formers were retained adequately. Of all the approaches studied for the analysis of the cocrystal formers, HILIC appears to be the best choice as the same column can be used for both acidic and basic cocrystal formers. With IPC, the ion-pairing reagent permanently alters the column chemistry and dedicated columns are required for each ion-pairing reagent used. CAD detection provided a linear response in the 80–100% test concentration range for the analytes studied here.     

离子色谱法测定氯膦酸二钠及其制剂的含量和有关物质

采用抑制型电导检测-离子色谱法同时测定氯膦酸二钠及其制剂的含量和有关物质.色谱条件为阴离子交换色谱柱(IonPac AS11-HC);检测方式为抑制电导检测;柱温30 ℃;流速1.2 mL/min;以KOH溶液为淋洗液,含量测定采用等度洗脱,有关物质检查采用梯度洗脱.氯膦酸二钠在0.0568～0.1895 g/L范围内线性关系良好(r＝0.9999); 注射液和胶囊的平均回收率分别为100.1%(RSD=0.7%)和98.9%(RSD=0.6%);检出限为0.3 ng.各杂质与主成分色谱峰能完全分离.     

Simultaneous Determination of 2-Imidazolines and Other Pharmaceutical Substances in Commercial Preparations by High-Performance Liquid-Chromatography

Abstract

A rapid HPLC method has been presented for the determination of some 2-imidazolines in several liquid or semi-solid commercial preparations. Two of the active ingredients were determined simultaneously whereas others were determined in the presence of dexamethasone and excipients. From the sample solutions no interference was observed on the chromatograms. Linearity and precision of the method have been assessed. The assay results obtained for various formulations were in accord with the declared amount.     

Determination of Vitamin B1 in Pharmaceutical Preparations by Flow-injection Analysis with Biamperometric Detection

IntroductionVitamin B1(VB1),also called thiamine,is animportant biomolecule,widely existing in beans,cere-al and meat,etc.So far,the application of spectropho-tometry[1,2],fluorimetry[3,4],high performance liquidchromatography[5],chemiluminescence[6]or potentiom-etry[7]for the determination of VB1has been reported.These methods have drawbacks,such as low selectivi-ty,elaborate procedures needed and a long responsetime.The dead-stop end-point biamperometry by usingtwo platinum foil electrodes…     

Determination of Gentamicin Sulphate in Injection Solutions by Derivative Spectrophotometry

Abstract

A new derivative spectrophotometric method was developed for determination of gentamicin beside methyl and propyl hydroxybenzoates in injection solutions. The determination was carried out after modifying the gentamicin molecule by reaction with o-phthal aldehyde. The obtained spectrum of product in methanol solution was converted into a third-derivative spectrum. The measurements were made at wavelength λ = 281 nm, where a linear relationship between D3 and antibiotic concentration occurs, when no coexisting constituents are present. The method is of high specificity to gentamicin in the presence of methyl and propyl hydroxybenzoates and has good accuracy. The recovery is from 99.38% to 100.16%, and wide linearity ranges from 0.004% to 0.008%. The method has satisfactory precision (RSD = 2.52%) as well as high sensitivity (LOD = 1.66 · 10^?4% and LOQ = 5.04 · 10^?4%).     

The Analysis of Gentamicin Sulphate in Pharmaceutical Specialities by High Performance Liquid Chromatography

Abstract

This paper describes an H.P.L.C. method for the assay of gentamicin sulphate, utilising pre-column derivatisation with an ophthalaldehyde/thioglycollic acid reagent, ion-paired chromatography of the derivative on a Hypersil O.D.S. column and U.V. detection. The four major components of gentamicin are resolved (Gentamicins C₁, C_1a, C₂ and C_2a) and evidence is presented to show that the method is stability indicating. The application of this technique to formulated products is described and figures for precision and accuracy as well as stability results are given.     

Simultaneous Determination of Tramadol and Ibuprofen in Pharmaceutical Preparations by First Order Derivative Spectrophotometric and LC Methods

The simultaneous determination of tramadol (Trama) and ibuprofen (Ibu) in solid dosage forms were done by two methods. The first involved determination using the first order derivative spectrophotometric technique at 230.5 and 280 nm over the concentration ranges of 5–50 and 5–100 μg mL^?1 with mean accuracies 99.84 and 99.98%, respectively. The second method was reversed-phase liquid chromatography using chlorzoxazone (Cxz) as an internal standard. Analysis was carried out using acetonirile—0.1% acetic acid (60 + 40, v/v) as the mobile phase with detection at 272 nm for Trama, Cxz and at 230 nm for Ibu with flow rates of 1 mL min^?1 and 1.3 mL min^?1, respectively. The retention times for Trama, Cxz and Ibu were 2.14, 4.10 and 9.04, respectivly. The mean recovery of Trama and Ibu was 99.91 and 99.92%. Due to its simplicity, rapidness, high precision and accuracy, the proposed methods can be used for the estimation of tramadol and ibuprofen in pharmaceutical preparations.     

Determination of Atenolol in Pharmaceutical Preparations by Gas Chromatography with Flame Ionization and Mass Spectrometric Detection

The present work describes the methodology and validation of gas chromatography with flame ionization (FID) and mass spectrometric (MS) detection after derivatization with N-Methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) for determination of atenolol with an internal standard (metoprolol) in pharmaceutical preparations. The linearity was established over the concentration range of 0.5–20 μg/mL for GC/FID and 12.5–500 ng/mL for GC/MS method. The intra- and inter-day relative standard deviation was less than 4.72 and 5.80%, respectively. Limit of quantification was determined as 500 ng/mL and 12.5 ng/mL for GC/FID and GC/MS, respectively. No interference was found from tablet excipients at the selected assay conditions. Developed GC/FID and GC/MS methods in this study are accurate, sensitive, and precise and can be easily applied to Tensinor tablet as pharmaceutical preparation.     

Determination of Defibrase in Pharmaceutical Formulation by LC with 6-Aminoquinolyl-N-hydroxysuccinimidyl Carbamate Derivatization and Fluorescence Detection

A sensitive LC method with pre-column fluorescence derivatization using 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate has been developed for the determination of defibrase from the venom of Agkistrodon acutus (also named defibrase in the Chinese Pharmacopoeia) in pharmaceutical formulation. By a denaturing procedure prior to derivatization, full and homogeneously derivatization of defibrase was obtained and demonstrated using MALDI-TOF-MS. The specificity of the method was validated by assessing interference from the placebo and by forced degradation. The method has demonstrated good linearity (r = 0.9998), accuracy (mean recovery 98.53%) and precision (RSD < 2.5%). Moreover, the method was found to be sensitive with a low limit of detection (3.35 ng mL^?1) and limit of quantitation (10.16 ng mL^?1). The method was successfully applied to the quantitative determination of defibrase in pharmaceutical formulation.     

LC Method with Precolumn Derivatization for Analysis of Mexiletine in Pharmaceutical Preparations

A isocratic, selective and accurate LC method of analysis of mexiletine in pharmaceutical preparations has been developed and validated. The method is based on derivatization of mexiletine with 4-chloro-7-nitrobenzofurazan in pH 9.0 borate buffer to yield a yellow product. Chromatography was performed on a C₁₈ column (150 × 4.6 mm i.d.) with acetonitrile–water 80:20 (v/v) as mobile phase at a flow rate of 1.0 mL min^?1. UV–visible absorbance detection was performed at 458 nm. The retention time of the mexiletine derivative was 4.10 min, and response was a linear function of concentration in the range 0.5–4.0 μg mL^?1 (r = 0.9998). The limits of detection and quantification were 0.05 and 0.15 μg mL^?1, respectively. Method validation revealed precision, sensitivity, and robustness were acceptable. Low RSD values are indicative of high precision, and high recovery values are indicative of the accuracy of the method. Results obtained by use of the proposed method for analysis of the mexiletine content of pharmaceutical a preparation were compared with those obtained by use of the official method. The method has been used for analysis of pharmaceutical preparations.     

差示分光光度法测定药物制剂中的四环素

提出了四环素与钴离子络合反应测定四环素的新方法,线性范围为０．８－２５μｇ／ｍＬ,ε＝１．３３＊１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１,回收率为９７．８％－１０１．５％。方法已用于制剂中四环素的测定。     

黄芩及其制剂中黄芩素和黄芩甙的

用毛细管区带电泳 -电化学检测法测定了黄芩及其制剂中黄芩素和黄芩甙的含量。研究了电极电位、电解液酸度和浓度、电泳电压及进样时间等对电泳的影响 ,得到了较为优化的测定条件。以直径为300μm的碳圆盘电极为检测电极 ,电极电位为0.90V(vsSCE) ,在100mmol/L硼酸盐缓冲液(pH9.0)中 ,上述两组分在8min内完全分离。黄芩素和黄芩甙浓度与电泳峰电流分别在5.0×10 -7～1.0×10 -3mol/L和1.0×10 -6～1.0×10 -3mol/L范围内呈良好线性 ,检出限分别为2.24×10 -7mol/L和5.48×10 -7mol/L。7次测定分别含5.0×10 -4mol/L黄芩素和黄芩甙试样溶液 ,峰高的相对标准偏差分别为3.53%和4.03%。