TLC Determination of Clobetasol Propionate in Topical Preparations,and Validation of the Method

JPC – Journal of Planar Chromatography – Modern TLC -     

Simultaneous Determination of Four Active Components in a Compound Formulation by Liquid Chromatography

Summary A rapid and accurate LC method is described for simultaneous determination of pseudoephedrine hydrochloride (PSE), acetaminophen (AMP), dextromethorphen hydrobromide (DEX), and diphenhydramine hydrochloride (DPH) in a compound formulation. Chromatographic separation of the four drugs was achieved on a Hypersil CN column (150 mm × 4.6 mm, 5 m particle) by use of a mobile phase comprising a mixture of 3 mM ion-pairing solution, 2% aqueous triethylamine solution, and 2 M phosphoric acid, 68:48:88 (v/v), pH 3.0, delivered at 1.0 mL min^–1. Compounds were detected at 215 nm and the run time was less than 10 min. The linearity, accuracy, and precision of the method were found to be acceptable over the concentration ranges 6.1–36.4 g mL^–1 for PSE, 65.0–390.0 g mL^–1 for AMP, 3.1–18.6 g mL^–1 for DEX, and 5.0–30.0 g mL^–1 for DPH.     

Simultaneous HPTLC Determination of Clotrimazole and Tinidazole in a Pharmaceutical Formulation

JPC – Journal of Planar Chromatography – Modern TLC - An HPTLC method for simultaneous determination of clotrimazole and tinidazole in a pharmaceutical formulation has been developed...     

Simultaneous Determination of Four Sudan Dyes in Egg Yolks by Molecularly Imprinted SPE Coupled with LC-UV Detection

A highly selective molecularly imprinted solid-phase extraction (MISPE) combined with liquid chromatography-ultraviolet detection was developed for the simultaneous isolation and determination of four Sudan dyes (I, II, III and IV) in egg-yolk products. The imprinted microspheres synthesized by suspension polymerization using phenylamine?Cnaphthol as mimic template show high selectivity and affinity to the four kinds of Sudan dyes and were successfully applied as selective sorbents of solid-phase extraction for the simultaneous determination of the four Sudans from egg-yolk samples. Good linearity was obtained in a range of 0.062?C10 ??g g^?1 and the average recoveries of the four Sudans at three spiked levels ranged from 94.1 to 102.5% with the relative standard deviations less than 5.8%. The developed extraction protocol eliminated the effect of template leakage on quantitative analysis and could be applied for the determination of Sudans in complicated food samples.     

A New Ecological RP-HPLC Method for the Determination of Pitavastatin,Fenofibrate and Their Impurities in a Novel Fixed Dose Combination

Chromatographia - We developed a simple, rapid, ecological RP-HPLC method for the estimation of Pitavastatin (PIT), Fenofibrate (FEN), and their impurities in a novel fixed dose combination. We...     

Method Development and Validation of a Rapid Determination of Ropinirole in Tablets by LC-UV

A reversed-phase high-performance liquid chromatographic (HPLC) method with UV detection was developed and validated for the determination of ropinirole (ROP) in tablets. The assay utilized UV detection at 250 nm and a Luna CN column (250 × 4.6 mm I.D, 5 μm). The mobile phases were comprised of acetonitrile: 10 mM nitric acid (pH 3.0) (75:25, v/v). Validation experiments were performed to demonstrate linearity, accuracy, precision, limit of quantitation (LOQ), limit of detection (LOD), and robustness. The method was linear over the concentration range of 0.5–10.0 μg mL⁻¹. The method showed good recoveries (99.75–100.20%) and the relative standard deviations of intra and inter-day assays were 0.38–1.69 and 0.45–1.95%, respectively. The method can be used for quality control assay of ropinirole.     

Determination of proline enantiomers in honey and royal jelly by LC-UV

The chiral separation and quantification of D-proline and L-proline in honey and royal jelly were examined by LC with UV detection. Most of the endogenous compounds existing in honey, such as sugars, were removed by using SPE cartridges containing C18 and strong cation-exchange sorbent. Other components, such as primary amino acids, were also removed by two-step derivatization with o-phthalaldehyde (OPA) and 9-fluorenylmethyl chloroformate (FMOC-CI). The components that were derivatized with OPA were separated from proline with a C18 cartridge. Proline was then converted into an FMOC derivative that could be subsequently measured by LC-UV. Sufficient chiral separation of D-proline and L-proline was achieved with an LC chiral column made of a beta-cyclodextrin phase in the polar organic-phase mode. The average recoveries of D-proline and L-proline from honey and royal jelly were in the range of 81.3-98.6% (RSD of < 1.8%). When this method was applied to commercial honey and royal jelly samples, L-proline was detected at concentrations of 369-1930 microg/g, whereas D-proline was not detected.     

氯菊酯胺菊酯混合防蛀剂的气相色谱法测定

用３％ＯＶ－１０１２ｍ×３ｍｍｉ．ｄ．玻璃或不锈钢柱,以邻苯二甲酸二（２－乙基）己酯为内标,在柱温２２３℃时同时测定氯菊酯胺菊酯混合防蛀剂中有效成分——氯菊酯和胺菊酯的质量分数。方法中氯菊酯和胺菊酯的平均变异系数分别为０．２０％和０．１９％。     

Determination of Tandospirone and its Impurities in Drug Formulations by LC-UV and LC-MS

This work describes the determination of tandospirone in bulk drug substance and formulated products by a reversed-phase liquid chromatographic method with UV detection. Chromatographic separation was performed on a C₁₈ column with a mobile phase of a binary mixture of methanol and water (70:30, v/v) delivered at a flow rate of 0.5 mL min^–1 and detection was performed at 243 nm. The proposed LC method is selective, precise and accurate for the determination of tandospirone in the presence of its manufacturing impurities with a limit of quantitation of 0.54 g mL^–1. A preliminary study for the identification of the major manufacturing impurities was made by liquid chromatography-mass spectrometry with electrospray ionization source operated in a positive ion mode.     

Simultaneous Determination of Thiocolchicoside and Diclofenac Diethyl Ammonium in Topical Gel Formulation by Square Wave Voltammetric Method

Russian Journal of Electrochemistry - A rapid, simple, sensitive, precise and specific square wave voltammetric method was developed for the simultaneous determination of Thiocolchicoside (TC) and...     

高速逆流色谱法分离和测定甾体激素

用自制的高速逆流色谱仪分离两酸睾丸素和氢化可的松注射剂，以氯仿－甲醇－水为溶剂体系及优化的色谱条件，对样品组分作了有效的分离，以苯甲酸为内标，获得令人满意的定量结果，标准偏差小于０．８％。     

Development and Validation of LC-UV for Simultaneous Estimation of Rosiglitazone and Glimepride in Human Plasma

A simple, sensitive and specific liquid chromatographic method with UV detection (228 nm) was developed for the simultaneous estimation of rosiglitazone and glimepride in human plasma. Rosiglitazone and glimepride were extracted from plasma using liquid–liquid extraction. Separation was achieved with an RP C₁₈ Column using a mixture of phosphate buffer (50 mM) with octane sulfonic acid (10 mM), methanol and acetonitrile as a mobile phase (55:10:35, v/v). pH was adjusted to 7.0. Amlodipine was used as an internal standard (IS). LOD of the method was found to be 20 ng mL^?1 for both drugs. Results were linear over the studied range 40.994–2007.556 ng mL^?1 for rosiglitazone (r ² ≥ 0.99) and 41.066–2094.84 ng mL^?1 for glimepride( r ² ≥ 0.99). The method was found to be simple, selective, precise and reproducible for the estimation of both drugs from spiked human plasma.     

Simultaneous Determination of Dipyrone and Papaverine in Pharmaceutical Formulation using PLS Regression and UV Spectrophotometry

Abstract

A combination of sodium dipyrone and papaverine hydrochloride is used as an analgesic and antispasmodic drug. A simple and rapid procedure is proposed for simultaneous determination of these drugs in commercial formulations (Melpaz^®) based on partial least squares (PLS) regression and UV spectrophotometric measurements in the range of 218–300 nm. The calibration set was built with 25 solutions in concentrations ranging from 15.0–35.0 mg ml^?1 for dipyrone and from 0.5–1.5 mg ml^?1 for papaverine in methanol. The relative standard deviation (RSD) was 1.05% for dipyrone and 1.55% for papaverine in pharmaceutical formulations. The percent of relative recovery was 95.9% for dipyrone and 95.2% for papaverine. Figures of merit, such as accuracy, precision, sensitivity and adjust were also determined. The methodology was validated by using an independent method, based on high performance liquid chromatography (HPLC).     

Development and Validation of LC-UV for Simultaneous Estimation of Rosiglitazone and Glimepride in Human Plasma

A simple, sensitive and specific liquid chromatographic method with UV detection (228 nm) was developed for the simultaneous estimation of rosiglitazone and glimepride in human plasma. Rosiglitazone and glimepride were extracted from plasma using liquid–liquid extraction. Separation was achieved with an RP C₁₈ Column using a mixture of phosphate buffer (50 mM) with octane sulfonic acid (10 mM), methanol and acetonitrile as a mobile phase (55:10:35, v/v). pH was adjusted to 7.0. Amlodipine was used as an internal standard (IS). LOD of the method was found to be 20 ng mL⁻¹ for both drugs. Results were linear over the studied range 40.994–2007.556 ng mL⁻¹ for rosiglitazone (r ² ≥ 0.99) and 41.066–2094.84 ng mL⁻¹ for glimepride( r ² ≥ 0.99). The method was found to be simple, selective, precise and reproducible for the estimation of both drugs from spiked human plasma.

     

固定波长同步荧光法同时分析2，2′－二羟基联苯和4－羟基联苯

建立了２，２′－二羟基联苯和４－羟基联苯的同时同步荧光分析法。方法简便快速。２，２′－二羟基联苯和４－羟基联苯的线性范围均为０～８μｇ／ｍＬ，检出限分别为６１ｎｇ／ｍＬ和８７ｎｇ／ｍＬ。     

Simultaneous Analysis of Pyridoxine and Melatonin in Tablet Formulation by Derivative Ultraviolet Spectroscopy

Abstract

A method for simultaneous analysis of pyridoxine and melatonin by second and third derivative UV - spectroscopy, the “zero - crossing” technique, is described. The determination has been carried out in 0.1 mol dm^?3 hydrochloric acid solution and the concentration range of 2 – 10 μg/ml pyridoxine and 0.5 – 3.5 μg/ml melatonin. Lower limits of detection at the 95% confidence level were 0.26 μg/ml for pyridoxine and 0.05μg/ml for melatonin The advantages of the proposed method include its application for the assay and in-vitro dissolution studies of pyridoxine and melatonin from two different tablet formulations.     

高效液相色谱-三重四极杆质谱法同时测定新型“香料”毒品中的10种合成大麻素

为测定新型"香料"毒品中常见的合成大麻素成分,研究开发了高效液相色谱-三重四极杆质谱联用分析方法。采用安捷伦Poroshell 120 EC-C18(3.0 mm×50 mm,2.7μm)色谱柱,以高纯水-甲醇作流动相进行梯度洗脱,柱温30℃,流速0.3 m L/min。采用电喷雾电离-正离子(ESI+)、负离子(ESI-)分段检测模式,并对合成大麻素的质谱特征和离子碎裂规律进行研究。结果表明,采用该方法可以实现对常见10种合成大麻素的定性和定量分析,正、负离子模式下检测的目标物分别在1~100,10~1 000 ng/m L范围内呈良好线性,日内相对标准偏差(RSD)均不大于3.2%,日间RSD均不大于6.3%。经加标回收率测定和实际样本检验,该方法快速、准确、灵敏、可靠,适用于新型"香料"毒品中常见合成大麻素成分的定性定量检测。     

柱前衍生化高效液相色谱法测定固定剂量复方抗结核制剂中盐酸乙胺丁醇的含量和溶出度

建立了快速、灵敏和准确的柱前衍生化高效液相色谱测定固定剂量复方抗结核制剂中盐酸乙胺丁醇的含量和溶出度的方法。在无水环境下,盐酸乙胺丁醇与苯乙基异氰酸酯发生柱前衍生化反应的最佳反应的物质的量比为1∶6,检测波长为215 nm。该法成功地用于由4种药物组成的复方抗结核制剂中盐酸乙胺丁醇的含量和溶出度的测定。     

Simultaneous Determination of Samarium and Gadolinium by a Automated Stopped-flow Analyzer

The present paper contains the reaction mechanism of the rare earth complex with 2-(2-arsenophenylazo)-7-(2, 6-dichloro-4-fluoro-phenylazo)- 1, 8-dihydroxynaphthalene-3, 6-disulfonic acid (DCF-arsenazo) studied preliminarily with a fully automated stopped-flow analyzer. A method with a high sensitivity and selectivity is proposed for the simultaneous determination of samarium and gadolinium based on the differential kinetic reaction of the rare earth complex with DCF-arsenazo. Sm and Gd in their concentrated oxides were determined with the relative errors less than 6%.     

同步荧光分析法同时测定叶绿素a和叶绿素b

众所周知,叶绿素a和叶绿素b(分别用Chla和Chlb表示)在绿色植物的光合作用中起着极重要的作用。它们的测定通常用于不同波长处测量吸光度或在不同激发-发射波长下测量荧光强度,而后解联立方程的光度法。