An Improved HPLC Method for Simultaneous Analysis of Losartan Potassium and Hydrochlorothiazide with the Aid of a Chemometric Protocol

An experimental design method was used for fast, simple, and accurate high-performance-pressure liquid chromatograpy (HPLC) determination of losartan and hydrochlorothiazide in combined dosage forms. This method avoids the disadvantages of the traditional analytical approach, which is time-consuming, involves a large number of runs, and does not allow the determination of multiple interacting parameters. On the basis of preliminary experiments, three independent variables (methanol content, pH value of the mobile phase, and flow rate) were selected as input, and as dependent variables, five responses (retention time of hydrochlorothiazide, retention time of losartan, asymmetry of hydrochlorothiazide peak, asymmetry of losartan peak, and resolution) were chosen. A full 2³ factorial design was used to determine which factors had an effect on the studied response. Afterwards, experimental design was used to optimize these influencing parameters in the previously selected experimental domain. After optimizing the experimental conditions, a separation was conducted on a Zorbax C₈ (150 mm × 4.6 mm, 5 μm particle size) column with a mobile phase consisting of methanol–acetonitrile–acetate buffer 45:20:35 v/v/v, pH 4.8 with flow rate of 0.82 mL min^?1 and column temperature of 25 °C. The developed method was successfully applied to simultaneous separation of these active drug compounds in their commercial pharmaceutical dosage forms.     

Comparison of HPLC and MEEKC for Miconazole Nitrate Determination in Pharmaceutical Formulation

A simple solid phase extraction (SPE) method coupled with high performance liquid chromatography (HPLC) using UV detector and microemulsion electrokinetic chromatography (MEEKC) has been developed and compared for the quantitative determination of miconazole nitrate in pharmaceutical formulation. For HPLC method, two parameters were optimized, namely, the wavelength and the mobile phases. The optimized condition was at the 225 nm wavelength and the mobile phase of ACN:MeOH (90:10 v/v). There are seven MEEKC parameters that were optimized, in this research, which were applied to voltage, temperature, wavelength, sodium dodecyl sulfate (SDS) concentration, buffer pH, buffer concentration and butan-1-ol concentration. The optimum MEEKC condition was obtained using 86.35 % (w/w) 2.5 mM borate buffer pH 9, 0.25 % (w/w) SDS, 0.8 % (w/w) ethyl acetate, 6.6 % w/w butan-1-ol and 6.0 % (w/w) acetonitrile. The combination of SPE using a diol column with HPLC–UV and the MEEKC methods were successfully applied for the determination of miconazole nitrate in a pharmaceutical formulation with the recovery percentage of 98.35 and 92.50 %, respectively.

     

Comparison of HPLC and MEEKC for Miconazole Nitrate Determination in Pharmaceutical Formulation

A simple solid phase extraction (SPE) method coupled with high performance liquid chromatography (HPLC) using UV detector and microemulsion electrokinetic chromatography (MEEKC) has been developed and compared for the quantitative determination of miconazole nitrate in pharmaceutical formulation. For HPLC method, two parameters were optimized, namely, the wavelength and the mobile phases. The optimized condition was at the 225 nm wavelength and the mobile phase of ACN:MeOH (90:10 v/v). There are seven MEEKC parameters that were optimized, in this research, which were applied to voltage, temperature, wavelength, sodium dodecyl sulfate (SDS) concentration, buffer pH, buffer concentration and butan-1-ol concentration. The optimum MEEKC condition was obtained using 86.35 % (w/w) 2.5 mM borate buffer pH 9, 0.25 % (w/w) SDS, 0.8 % (w/w) ethyl acetate, 6.6 % w/w butan-1-ol and 6.0 % (w/w) acetonitrile. The combination of SPE using a diol column with HPLC–UV and the MEEKC methods were successfully applied for the determination of miconazole nitrate in a pharmaceutical formulation with the recovery percentage of 98.35 and 92.50 %, respectively.     

Validated HPLC Method for Separation and Determination of Terbutaline Enantiomers

Abstract

A simple, rapid, and validated method for separation and determination of terbutaline enantiomers was developed. Terbutaline was separated and determined on a Vancomycin Chirobiotic V column (250 × 4.6 mm), using a mixture of methanol, acetic acid, and triethylamine (100:0.1:0.1% v/v/v) as a mobile phase at 20°C and at a flow rate of 1 ml/min. The UV detector was set to 276 nm. Acetyl salicylic acid (aspirin) was used as an internal standard. The applied high-performance liquid chromatography (HPLC) method allowed separation and quantification of terbutaline enantiomers with good linearity (r > 0.999) in the studied range. The relative standard deviations (RSD) were 1.10 and 1.32% for the terbutaline enantiomers with accuracy of 99.80 and 99.55. The limit of detection and limit of quantification of terbutaline enantiomers were found to be 0.05 and 0.10 µg · ml^?1, respectively. The method was validated through the parameters of linearity, accuracy, precision, and robustness. The HPLC method was applied for the quantitative determination of terbutaline in pharmaceutical formulations.     

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...     

AQbD-Oriented Development of a New LC Method for Simultaneous Determination of Telmisartan and Its Impurities

Analytical quality by design (AQbD)-oriented liquid chromatographic method development for determination of telmisartan and its impurities A, C, and 1 is determination is presented. Step-by-step process was conducted in order to define reliable design space. At the beginning, critical process parameters with the highest influence on method performance were defined: acetonitrile content in the first (ACN 1) and second (ACN 2) gradient step and time (t ₂) the second gradient step. These factors were varied according to Box–Behnken plan of experiments and their influence on retention times of impurities A and C, S value between telmisartan and impurity 1 and peak capacity were followed. In this way, the relationship between the critical process parameters and critical quality attributes was established. The obtained mathematical models and Monte Carlo simulations were used to identify the design space. Fractional factorial design was applied for experimental robustness testing, and the method was validated to verify the adequacy of selected optimal conditions. Finally, all validation parameters were tested, and adequacy of the method was confirmed. Applicability as a routine method was confirmed by analysis of commercially available tablets.     

HPTLC Method for Determination of Colchicine in a Pharmaceutical Formulation

JPC – Journal of Planar Chromatography – Modern TLC - An HPTLC method, using an internal standard, for analysis of colchicine in a pharmaceutical formulation, has been established and...     

Application of Heart-Cutting 2D-LC for the Determination of Peak Purity for a Chiral Pharmaceutical Compound by HPLC

As an alterative to photodiode array or mass spectral analysis, a heart-cutting two-dimensional liquid chromatography technique (2D-LC) can be utilized to assess peak purity. In this work, the strengths of the heart-cutting 2D-LC technique are presented by highlighting a case study where a co-eluting impurity present at 0.8 % was non-detectable using traditional methods. However, when fractions taken across the main peak were re-assayed using an orthogonal method, this peak was readily observed. With modern switching valves and up-to-date chromatography software, implementing this technique into a validation protocol for assessing peak purity is simple and can be accomplished through only minor modifications to existing HPLC equipment.     

化学计量学方法同时测定铁、铝和铍

采用正交信号校正(OSC)-小波包变换(WPT)-偏最小二乘法(PLS)(OSCW-PTPLS)相结合的化学计量学方法,用于不经化学分离解析光谱严重重叠的Fe(Ⅲ)、Al(Ⅲ)和Be(Ⅱ)混合物。该法结合OSC,WPT和PLS三种技术提高了获取特征信息的能力和回归质量。本文测定的三种金属离子可与铬天青S和溴化十六烷基吡啶(CPB)在pH=5.60的邻苯二甲酸氢钾-NaOH缓冲溶液中发生高灵敏度和低选择性的显色反应。设计了一个名为POSCWPTPLS的程序来执行相关计算。实验结果显示OSCWPTPLS方法优于PLS方法。     

亲水作用色谱法测定表阿霉素及其杂质

建立了一种以亲水作用色谱分离测定表阿霉素的新方法。采用硅胶色谱柱及高极性有机溶剂水相缓冲溶液流动相。对流动相的pH、缓冲溶液的浓度及流速进行了优化,确定了以乙腈甲酸钠缓冲溶液(pH2.9)(90∶10,V/V)作为流动相的最佳条件。对优化的分离条件进行系统适应性实验,结果表明表阿霉素与有关杂质之间的分离度和拖尾因子均达到药典要求。该法具有良好的线性(相关系数0.9971～0.9991)和重复性(峰面积RSD<1.0%),方法简便实用,用于实际样品分析,结果满意。     

A New HPLC Method for the Simultaneous Determination of Acetaminophen,Phenylephrine, Dextromethorphan and Chlorpheniramine in Pharmaceutical Formulations

Abstract

Acetaminophen, phenylephrine, dextromethorphan, and chlorpheniramine are frequently associated in pharmaceutical formulations against the common cold. A new high performance liquid chromatography (HPLC) method has been developed for the simultaneous determination of these active pharmaceutical ingredients in pharmaceutical formulations. The separation and quantitation were achieved on a 25 cm underivatized silica column using a mobile phase of methanol: water (containing 6.0 g of ammonium acetate and 10 ml of triethylamine per liter, pH adjusted to 5.0 with orthophosphoric acid), 95:5%(v/v). Detection was carried out using a variable wavelength UV-vis detector at 254 nm for acetaminophen, at 220 nm for phenylephrine, and at 227 nm for dextromethorphan and chlorpheniramine. The method showed linearity for the acetaminophen, phenylephrine, dextromethorphan, and chlorpheniramine in the 162.5–650, 2.5–10, 7.5–30, and 1–4 µg/ml ranges, respectively. The intraday and interday RSDs ranged from 0.92 to 1.52%, 1.00 to 1.76%, 1.21 to 1.74% and 1.26 to 1.80% for the acetaminophen, phenylephrine, dextromethorphan, and chlorpheniramine, respectively. Compounds were eluted in a run time of less than 12 min.     

Sequential Injection Method for the Determination of Oxprenolol in Pharmaceutical Products Using Chemometric Methods of Optimization

A sequential injection (SI) spectrophotometric method for the determination of oxprenolol in pharmaceutical products was developed. The method is based on the oxidation of oxprenolol on-line with Ce(IV) in sulfuric acid medium and the subsequent monitoring of the absorbance of the oxidized form of the drug at 480 nm. The procedure was optimized by the orthogonal array design at two and four levels. The factors included in the optimization were Ce(IV) concentration, sulfuric acid concentration, and the stop time of the composite zone at the reaction coil. The optimized SI system with a linear dynamic range of 50–400 ppm was found to be suitable for the assay of oxprenolol in pharmaceutical products.     

Simultaneous Determination of Impurities in Ropinirole Tablets by an Improved HPLC Method Coupled with Diode Array Detection

A gradient HPLC method coupled with diode array detection was developed and fully validated for the analysis of impurities in ropinirole using a Kromasil^® C8 100 Å (250 × 4.6 mm, 5 μm) column with a flow rate 1.0 mL min^?1 and detection at 250 nm. The mobile phase component A consisted of a mixture of 19.6 mM aqueous potassium dihydrogen phosphate–acetonitrile (98:2 v/v), pH adjusted to 7.0 with triethylamine and the mobile phase component B consisted of acetonitrile. The method was validated in terms of linearity, sensitivity, precision, accuracy and stability. The calibration curves for ropinirole and its five impurities showed good linearity (r > 0.998) within the calibration ranges tested. The intra- and inter-day RSD values were <3.9 %, while the relative percentage error E _r was <5.8 % for all compounds. Accelerated stability studies performed under various stress conditions including oxidation, hydrolysis and UV light irradiation at 254 nm proved the selectivity of the procedure. Long-term stability studies performed on blistered tablets and under various conditions of heat and humidity indicate the presence of four of the studied impurities in less than 0.07 %. The method was applied successfully to the detection and determination of ropinirole impurities in pharmaceutical formulations.     

手性毛细管色谱法测定人尿中美芬妥英对映体的含量及其在代谢分型中的应用

采用手性毛细管色谱柱和ＦＩＤ检测器建立了人尿中美芬妥英（ＭＰ）对映体的定量分析方法。尿样用二氯乙烷提取，用酸、碱洗涤得以纯化，测得各对映体的最低检测限为６０μｇ／Ｌ。在１１５～６９０μｇ／Ｌ浓度范围内，标准曲线呈良好的线性关系，ｒ＞０．９９，日内、日间精密度ＲＳＤ＜６．５％，Ｓ－ＭＰ的平均回收率为７４．４１％，Ｒ－ＭＰ的平均回收率为７３．７８％。并以ＭＰ为探针药物，对３２名志愿者的尿样进行了ＭＰ氧化代谢分型研究。     

高效液相色谱法分离药物对映体中手性流动相添加剂的应用

综述了近年来手性流动相添加剂在高效液相色谱拆分对映体中的应用,阐述了各类手性流动相添加剂的拆分机理及其在药物分析中的应用,引用文献52篇.     

HPLC and UPLC Methods for the Simultaneous Determination of Enalapril and Hydrochlorothiazide in Pharmaceutical Dosage Forms

High efficiency and less elution are the basic requirements of high-speed chromatographic separation. In this study, a new gradient reverse phase chromatographic methods were developed using HPLC and UPLC systems for simultaneous determination of enalapril maleate (ENL) and hydrochlorothiazide (HCZ) in pharmaceutical dosage forms. The chromatographic separations of ENL and HCZ were achieved on a Waters μ-Bondapak C 18, (300 × 3.9 mm, 10 μm) and Waters Acquity BEH C18 (100 × 2.1 mm, 1.7 μm) columns for HPLC within 5.30 min and UPLC within a short retention time of 1.95 min, respectively. A linear response was observed over the concentration range 0.270–399 μg mL⁻¹ of ENL, 0.260–399 μg mL⁻¹ of HCZ for HPLC system and 0.270–399 μg mL⁻¹ of ENL and 0.065–249 μg mL⁻¹ of HCZ for UPLC system. Also, limit of detection for ENL was 1.848 ng mL⁻¹ and 31.477 ng mL⁻¹ for HCZ, 2.804 ng mL⁻¹ for ENL and 2.943 ng mL⁻¹ for HCZ using HPLC and UPLC, respectively. The proposed methods were validated according to ICH guideline with respect to precision, accuracy, and linearity. Forced degradation studies were also performed for both compounds in bulk drug samples to demonstrate the specificity and stability indicating power of the HPLC method. Comparison of system performance with conventional HPLC was made with respect to analysis time, efficiency, and resolution.

     

Development of the HPLC Method for Simultaneous Determination of Lidocaine Hydrochloride and Tribenoside Along with Their Impurities Supported by the QSRR Approach

A new liquid chromatographic (LC) method for simultaneous determination of lidocaine hydrochloride (LH) and tribenoside (TR) along with their related compounds in pharmaceutical preparations is described. Satisfactory LC separation of all analytes after the liquid–liquid extraction (LLE) procedure with ethanol was performed on a C₁₈ column using a gradient elution of a mixture of acetonitrile and 0.1 % orthophosphoric acid as the mobile phase. The procedure was validated according to the ICH guidelines. The limits of detection (LOD) and quantification (LOQ) were 4.36 and 13.21 μg mL^?1 for LH, 7.60 and 23.04 μg mL^?1 for TR, and below 0.11 and 0.33 μg mL^?1 for their impurities, respectively. Intra- and inter-day precision was below 1.97 %, whereas accuracy for all analytes ranged from 98.17 to 101.94 %. The proposed method was sensitive, robust, and specific allowing reliable simultaneous quantification of all mentioned compounds. Moreover, a comparative study of the RP-LC column classification based on the quantitative structure-retention relationships (QSRR) and column selectivity obtained in real pharmaceutical analysis was innovatively applied using factor analysis (FA). In the column performance test, the analysis of LH and TR in the presence of their impurities was carried out according to the developed method with the use of 12 RP-LC stationary phases previously tested under the QSRR conditions. The obtained results confirmed that the classes of the stationary phases selected in accordance with the QSRR models provided comparable separation for LH, TR, and their impurities. Hence, it was concluded that the proposed QSRR approach could be considered a supportive tool in the selection of the suitable column for the pharmaceutical analysis.     

HPLC and UPLC Methods for the Simultaneous Determination of Enalapril and Hydrochlorothiazide in Pharmaceutical Dosage Forms

High efficiency and less elution are the basic requirements of high-speed chromatographic separation. In this study, a new gradient reverse phase chromatographic methods were developed using HPLC and UPLC systems for simultaneous determination of enalapril maleate (ENL) and hydrochlorothiazide (HCZ) in pharmaceutical dosage forms. The chromatographic separations of ENL and HCZ were achieved on a Waters μ-Bondapak C 18, (300 × 3.9 mm, 10 μm) and Waters Acquity BEH C18 (100 × 2.1 mm, 1.7 μm) columns for HPLC within 5.30 min and UPLC within a short retention time of 1.95 min, respectively. A linear response was observed over the concentration range 0.270–399 μg mL^?1 of ENL, 0.260–399 μg mL^?1 of HCZ for HPLC system and 0.270–399 μg mL^?1 of ENL and 0.065–249 μg mL^?1 of HCZ for UPLC system. Also, limit of detection for ENL was 1.848 ng mL^?1 and 31.477 ng mL^?1 for HCZ, 2.804 ng mL^?1 for ENL and 2.943 ng mL^?1 for HCZ using HPLC and UPLC, respectively. The proposed methods were validated according to ICH guideline with respect to precision, accuracy, and linearity. Forced degradation studies were also performed for both compounds in bulk drug samples to demonstrate the specificity and stability indicating power of the HPLC method. Comparison of system performance with conventional HPLC was made with respect to analysis time, efficiency, and resolution.     

反相液相色谱法同时测定原料药中吉非替尼及其有关物质的含量

采用Phenomenex Gemini C18色谱柱,以乙腈-0.15%醋酸铵缓冲液为流动相,紫外检测器检测,通过对流动相组成、缓冲溶液浓度、p H值、检测波长等色谱条件进行研究,建立了同时测定原料药中吉非替尼及其有关物质含量的反相高效液相色谱法。结果表明:以乙腈-0.15%醋酸铵缓冲溶液(p H 8.5)为流动相,流速1.0 m L/min,检测波长255 nm,在40℃柱温下采用梯度洗脱可较好地分离原料药中吉非替尼及其9种有关物质;吉非替尼及其有关物质的质量浓度在0.012 0~4.202μg/m L范围内呈良好线性关系(r0.999 0),检出限为0.001 7~0.094 1μg/m L,平均回收率和相对标准偏差(RSD)分别为99.7%~100.9%和0.06%~0.70%。该法已成功应用于吉非替尼原料药主成分及有关物质的同时测定,且检测灵敏度高,重现性好,结果准确可靠,可作为吉非替尼原料药质量控制的标准。