胶束电动毛细管色谱法同时测定阿咖酚散中3种有效成分

建立了胶束电动毛细管色谱同时分离测定阿咖酚散中咖啡因、对乙酰氨基酚、阿司匹林3种有效成分的方法。对以有机碱三乙醇胺为改进剂的胆酸胶束相进行了优化,对改进剂的影响机理进行了详细讨论。最佳电泳条件如下:以40 mmol/L硼酸盐-60 mmol/L胆酸-12.5%三乙醇胺(pH 12.0)为缓冲体系,分离电压为15 kV,检测波长为254 nm。在上述条件下,14 min内实现了阿咖酚散中3组分的基线分离。咖啡因、对乙酰氨基酚和阿司匹林的线性范围分别为18.75～900.0(r=0.999 9)、2.60～62.50(r=0.992 9)、79.17～3 800 mg/L(r=0.994 0)。上述3组分迁移时间和峰高的相对标准偏差分别不高于1.8%和6.8%。咖啡因、对乙酰氨基酚和阿司匹林的检出限分别为4.6、0.17、38 mg/L。应用该法测定阿咖酚散中上述3组分,加标回收率分别为100%、100%和102%,可满足实际样品分析要求。所建立的方法简便、快速、灵敏、经济,能同时进行阿咖酚散中多种成分的分离测定。     

高效液相色谱仪蒸发光散射检测器两种校准用标准物质的比较选择

对高效液相色谱蒸发光散射检测器(ELSD)校准用标准物质对乙酰氨基酚–甲醇溶液和咖啡因–甲醇溶液进行了比较选择。与对乙酰氨基酚相比,咖啡因的缺点是色谱峰对称性稍差,优点是没有杂质峰,更重要的是咖啡因已经研制出国家二级标准物质,可以很好地溯源,所以咖啡因更适合作ELSD的校准物质。     

高效液相色谱多波长同时测定阿咖酚散中对乙酰氨基酚、咖啡因、阿司匹林、水杨酸

采用高效液相色谱多波长同时测定阿咖酚散中对乙酰氨基酚、咖啡因、阿司匹林、水杨酸的含量。使用岛津LC–20AT高效液相色谱仪、Venusil MP–C_(18)(150 mm×4.6 mm,5μm)色谱柱,采用多波长进行分析。流动相为磷酸盐缓冲液(0.01 mol/L磷酸二氢钾溶液,用磷酸调节pH为2.6±0.1)–甲醇(体积比为7∶3),流量为1.0 mL/min,检测波长:对乙酰氨基酚、咖啡因276 nm,阿司匹林254 nm,水杨酸241 nm,柱温为30℃。3种主要成分和有关杂质的分离度良好,标准曲线线性相关系数均大于0.997。乙酰氨基酚、咖啡因、阿司匹林、水杨酸的平均回收率分别为99.9%、101.2%、98.4%、99.0%,测定结果的相对标准偏差分别为1.16%、1.35%、1.23%、20.0%(n=5)。多波长法测定阿咖酚散中3种成分及杂质准确、灵敏,可以用于阿咖酚散的定量检测和质量控制。     

大口径毛细管气相色谱法直接测定复方阿司匹林制剂

建立了同时测定复方阿司匹林制剂中阿司匹林、对乙酰氨基酚、咖啡因及降解产物水杨酸的大口径毛细管气相色谱法。在HP-1大口径色谱柱上直接进样,无需衍生化处理,所测组分与内标物2 min内达到基线分离。各组分在其线性范围内线性关系良好(相关系数均高于0.999),检出限分别为10.0μg/L、5.0μg/L、1.0μg/L和1.0μg/L。经样品测定,平均回收率为97.46%~101.24%。该法简便、快速、准确、重现性好,可用于复方阿司匹林制剂的质量控制。     

NMR定量测定片剂中的对乙酰氨基酚

以基准试剂邻苯二甲酸氢钾为内标,采用1H NMR法建立了对乙酰氨基酚片剂中对乙酰氨基酚含量的测定方法。考察了延迟时间、脉冲宽度和采样次数对测定结果的影响。选定核磁共振参数延迟时间1 s、脉冲宽度3μs、采样次数16次。结果显示,测定内标与标样的NMR峰面积比均小于0.4%,方法具有很好的重复性。将内标与标样的NMR峰面积比对其质量比绘制标准曲线,相关系数为1.000 0,内标的质量浓度为6 g/L时,对乙酰氨基酚的线性范围为2～10 g/L。用标准曲线法和绝对定量模式(内标法)测定了3种不同厂家的片剂中对乙酰氨基酚的含量。结果表明此方法与紫外分光光度法的测定结果一致,方法简单易行、结果准确。     

毛细管气相色谱法测定速效伤风胶囊中对乙酰氨基酚、咖啡因、马来酸氯苯那敏的含量

用５％Ｐｈ－Ｍｅ－Ｓｉｌｉｃｏｎｅ毛细管色谱柱，ＦＩＤ，二阶程序升温，以正十六烷作为内标物测定速效伤风胶囊中对乙酰氨基酚、咖啡因、马来酸氯苯那敏的含量。浓度线性范围：对乙酰氨基酚４～２０ｇ／Ｌ，咖啡因０．０８４～０．４２ｇ／Ｌ，马来酸氯苯那敏０．１５～０．７５ｇ／Ｌ。平均回收率（ｎ＝５）：对乙酰氨基酚９９．６２％（ＲＳＤ＝０．４４％）咖啡因９６．４６％（ＲＳＤ＝１．３２％），马来酸氯苯那敏９８．５５％（ＲＳＤ＝０．６５％）。     

毛细管气相色谱法测定速效伤风胶囊中对乙酰氨基酚、咖啡因、马来酸氯苯那敏的含量

 用５％Ｐｈ－Ｍｅ－Ｓｉｌｉｃｏｎｅ毛细管色谱柱，ＦＩＤ，二阶程序升温，以正十六烷作为内标物测定速效伤风胶囊中对乙酰氨基酚、咖啡因、马来酸氯苯那敏的含量。浓度线性范围：对乙酰氨基酚４～２０ｇ／Ｌ，咖啡因０．０８４～０．４２ｇ／Ｌ，马来酸氯苯那敏０．１５～０．７５ｇ／Ｌ。平均回收率（ｎ＝５）：对乙酰氨基酚９９．６２％（ＲＳＤ＝０．４４％）咖啡因９６．４６％（ＲＳＤ＝１．３２％），马来酸氯苯那敏９８．５５％（ＲＳＤ＝０．６５％）。     

超临界流体色谱法测定复方氨酚烷胺中咖啡因和对乙酰氨基酚含量

建立超临界流体色谱法分离测定复方氨酚烷胺中咖啡因和对乙酰氨基酚含量的方法,并研究其影响因素.Kromasil Slica填充柱(250×4.6mm,5μm),流动相为含18%甲醇的CO2,流速2.0mL/min,柱温50℃,背压200bar,检测波长275nm.在测定范围内,对照品浓度与峰面积呈良好的线性关系,以峰面积和保留时间计算精密度分别为咖啡因0.49%.1.88%和对乙酰氨基酚0.44%和1.09%.该方法在所用分析条件下,5 min即可完成测定,且具有较好的重现性和线性关系.     

库仑滴定法测定对乙酰氨基酚

１引言中国药典（二部）１９９５年版推荐的对乙酰氨基酚（扑热息痛）的测定方法为紫外分光光度法。我们根据其易与Ｂｒ２发生取代反应的结构特点，采用库仑滴定法以电生溴为滴定剂方法反应速度快，电流效率容易达到１００％。用两个极化电极的电流法，即死停终点法指示终点。用于扑热息痛片剂样品的分析取得了满意结果。２实验部分２．１仪器与试剂ＫＬＴ－１型通用库仑仪（江苏分析仪器厂）；微量进样器（上海医用激光仪器厂）；比色管。对乙酰氨基酚对照品（含量≥９７．０％，中国药品生物制品检定所）；扑热息痛片剂（北京第四制药厂）…     

鲁米诺-过氧化氢-纳米银化学发光体系测定药物中的对乙酰氨基酚

碱性条件下,对乙酰氨基酚对鲁米诺-过氧化氢-纳米银化学发光体系有较强的抑制作用,基于此,结合流动注射技术,建立了测定对乙酰氨基酚的新方法。研究了影响化学发光强度的各种因素,并初步探讨了可能的发光机理。在最佳实验条件下,对乙酰氨基酚浓度在2.0×10-8~1.0×10-4mol/L范围内与相对发光强度呈线性关系,检出限(3σ)为4.0×10-9mol/L。对1.0×10-7mol/L的对乙酰氨基酚平行测定9次,相对标准偏差为2.6%。该法用于片剂中扑热息痛含量的测定,结果令人满意。     

Artificial neural network for simultaneous determination of two components of compound paracetamol and diphenhydramine hydrochloride powder on NIR spectroscopy

Diffuse reflectance near-infrared (NIR) spectroscopy is a technique widely used for rapid and non-destructive analysis of solid samples. A method for simultaneous analysis of the two components of compound paracetamol and diphenhydramine hydrochloride powdered drug has been developed by using artificial neural network (ANN) on near-infrared (NIR) spectroscopy. An ANN containing three layers of nodes was trained. Various ANN models based on pretreated spectra (first-derivative, second-derivative and standard normal variate; SNV) were tested and compared, respectively. In the models the concentration of paracetamol and caffeine as active principles of compound paracetamol and diphenhydramine hydrochloride powder was determined simultaneously. Partial least squares regression (PLS) multivariate calibrations were also used, which were compared with ANN. The best model was obtained at first-derivative spectra. We have also discussed the parameters that affected the networks and predicted the test set (unknown) specimens. The degree of approximation, a new evaluation criteria of the network were employed, which proved the accuracy of the predicted results.     

Determination of caffeine in solid pharmaceutical samples by FTIR spectroscopy

Fourier transform infrared spectroscopy has been used for the quantitative determination of caffeine in several pharmaceutical products: acetyl salicylic acid, paracetamol and propyphenazone. The method is simple, rapid and selective, and allows the determination of caffeine without sample pretreatment and without separation from the matrix. Two techniques for measuring the infrared spectra of caffeine are described: transmission through pellets and diffuse reflectance from powder (DRIFT). In both methods, samples were diluted (1%) with KBr. Caffeine in pharmaceutical matrices was recovered within 5% error in pellets and 10% by DRIFT. Relative standard deviations were generally 1.5% for repeated measurements on a single pellet and 5% for measurements on different pellets. DRIFT in the vacuum mode gave rather large RSDs. The limit of detection of the pellet technique was about 0.5% caffeine in the original sample.     

Validated ecofriendly chromatographic method for quantitative determination of anti‐migraine quaternary mixture

A novel ecofriendly, cost and time saving high‐performance thin‐layer chromatographic method was developed and validated for simultaneous determination of metoclopramide, ergotamine, caffeine, and paracetamol in bulk and pharmaceutical formulation. The separation was carried out on silica gel plates, using ethyl acetate:ethanol:ammonia (9:1:0.1, v/v/v) as a developing system. Ultraviolet detection was carried out at 272 nm. The resulting retention times were 0.15, 0.36, 0.49, and 0.74 min for metoclopramide, ergotamine, caffeine, and paracetamol, respectively. The greenness profile assessment was achieved to the proposed method to evaluate its greenness characters to the environment with acceptable results. Validation parameters were checked according to International Conference of Harmonization guidelines to achieve the international requirements for quality control analysis of the proposed drugs.     

An efficient and simultaneous analysis of caffeine and paracetamol in pharmaceutical formulations using TLC with a fluorescence plate reader

A simple, rapid, and efficient method using TLC with a fluorescence plate reader has been described for simultaneous determination of caffeine and paracetamol. Determination was carried out using the fluorescence-quenching action of caffeine and paracetamol on a TLC plate with a fluorescent indicator at lambda ex = 254 nm in the linear ranges of 0.2-1.9 and 0.03-1.5 microg/L, respectively. Separation of caffeine and paracetamol were performed on the TLC plate, and the best results were obtained using the optimized mobile phase n-hexane-ethyl acetate-ethanol (2.5 + 1.5 + 0.4, v/v). Some important parameters, such as solvent type and ratio of the mobile phase, the presence of other components, and instrumental parameters, were studied. Caffeine and paracetamol detection limits were 0.025 and 0.032 microg/L, and RSD values for 0.6 microg/L caffeine and 0.06 microg/L paracetamol (n = 5) were 1.93 and 2.06%, respectively. Using this technique, some pharmaceuticals containing caffeine and paracetamol were analyzed with satisfactory results.     

高效液相色谱-双波长检测-梯度洗脱法同时测定小儿氨酚烷胺颗粒中的3种有效组分

建立了高效液相色谱(HPLC)-双波长检测-梯度洗脱同时测定小儿氨酚烷胺颗粒中对乙酰氨基酚、咖啡因和马来酸氯苯那敏含量的分析方法。采用的色谱条件: 以Diamonsil C18色谱柱(4.6×200 mm, 5 μm)为分离柱,以乙腈和0.1%三乙胺水溶液(用磷酸调pH至3.7±0.5)为流动相进行梯度洗脱,流速1.0 mL/min,检测波长为280 nm和210 nm,柱温为30 ℃,进样量为5 μL。结果表明,对乙酰氨基酚、咖啡因和马来酸氯苯那敏的线性范围均比较宽(依次为2.4～60、0.14～3.6、0.019～0.48 μg),平均加标回收率均不低于99.0%,而且方法操作简单,重现性好,测定结果准确,可用于更好地控制该制剂的质量。     

Simultaneous Voltammetric Determination of Paracetamol,Codeine and Caffeine on Diamond‐like Carbon Porous Electrodes

A porous electrode material combining the features of vertically aligned multi‐walled carbon nanotubes (VAMWCNT) and diamond‐like carbon films (DLC) have been developed for a highly sensitive electrochemical sensor. For working electrode preparation, DLC has been grown onto VAMWCNT, forming a porous, conductive and stable composite. The electrochemical performance of this DLC:VAMWCNT electrode has been investigated toward detection and analysis of three well‐known molecules, namely paracetamol, codeine and caffeine. A ternary mixture of these analytes was simultaneously determined under optimum experimental conditions using square‐wave voltammetry. Wide linear concentration ranges and the limits of detection of 3.34×10⁻⁷ mol L⁻¹, 1.57×10⁻⁷ mol L⁻¹ and 3.67×10⁻⁷ mol L⁻¹ were obtained for paracetamol, codeine and caffeine, respectively. We conclude that the proposed voltammetric method and the DLC:VAMWCNT electrode comprise a reliable methodology for simultaneous determination of paracetamol, codeine and caffeine in biological matrix samples.     

A Study on the Reaction of Periodate with Paracetamol and Its Application

Abstract

Periodate has been determined using fluorometric analysis of the fluorescent product when periodate and paracetamol were mixed in acidic medium. The calibration graph was linear between 4.8×10^?7–5.6×10^?6 mol/liter, and the detection limit is 4.0×10^?8 mol/liter. The proposed method was applied to the determination of the total content of different iodine forms in kelp samples, and the results were satisfactory.     

Development of a Multimatrix UHPLC-MS/MS Method for the Determination of Paracetamol and Its Metabolites in Animal Tissues

Paracetamol/acetaminophen (APAP) is one of the most popular pharmacologically active substances used as an analgesic and antipyretic agent. The metabolism of this drug occurs in the liver and leads to the formation of two main metabolites—glucuronic acid and sulfate derivate. Despite the wide use of paracetamol in veterinary medicine, a handful of analytical methods were published for the determination of paracetamol residues in animal tissues. In this paper, a multimatrix method has been developed for the determination of paracetamol and two metabolites—paracetamol sulfate (PS) and p-Acetamidophenyl β-D-glucuronide (PG). A validation procedure was conducted to verify method reliability and fit purpose as a tool for analyzing acetaminophen and metabolites in muscle, liver, lung, and kidney samples from different species of animals. Established validation parameters were in agreement with acceptable criteria laid by the European legislation. The initial significant matrix effect was successfully reduced by implementing an internal standard—4-Acetamidophenyl β-D-glucuronide-d3 (PG-d3, IS). The usefulness of the developed method was verified by analyzing samples from an experiment in which paracetamol was administrated to geese.     

Simultaneous determination of ascorbic acid, caffeine and paracetamol in drug formulations by differential-pulse voltammetry using a glassy carbon electrode

A simple, rapid and accurate method for the simultaneous determination of ascorbic acid, caffeine and paracetamol in drug formulations has been developed. Peak currents were measured with a glassy carbon electrode at +0.350, +0.618 and +1.425 V versus a saturated calomel electrode for ascorbic acid, paracetamol and caffeine, respectively. Perchloric acid (0.1 M) - methanol (1 + 1) was used both as a solvent and supporting electrolyte. The optimum modulation amplitude, pulse repeat time and scan rate of the polarographic analyser were found to be 50 mV, 0.5 s and 5 mV s-1, respectively and the linear calibration ranges for ascorbic acid, caffeine and paracetamol were 0-35, 0-50, and 0-55 micrograms ml-1, respectively. The relative standard deviations for 9.30 micrograms ml-1 of ascorbic acid, 8.50 micrograms ml-1 of caffeine and 7.30 micrograms ml-1 of paracetamol were 1.3, 2.5 and 0.7%, respectively. Results are reported for several commercially available drugs.     

Simultaneous Spectrofluorimetric Determination of Paracetamol and Caffeine in Pharmaceutical Preparations in Solid‐Phase Using Partial Least Squares Multivariate Calibration

Abstract

Partial least‐squares algorithm (PLS)‐1 was used for the solid‐phase spectrofluorimetric determination of paracetamol (PA) and caffeine (CF) in pharmaceutical formulations. In despite of the closely overlapping spectral bands, the method allows the simultaneous quantification and sample preparation prior to analysis is not required. The calibration set consisted of 96 samples with 100–400 mg/g^?1 PA plus 10–65 mg/g^?1 CF; another set of 25 samples was used for external validation. Agreement between predicted and experimental concentrations was fair (r=0.993 and 0.964 for PA and CF models). Prediction performance was evaluated in terms of the coefficient of variability (CV), relative predictive determination (RPD), and ratio error range (RER). The PLS‐1 model was used for the determination of PA and CF in pharmaceutical formulations.