High-Performance Liquid Chromatographic Determination of Roxithromycin in Tablets

Abstract

For the quantitative determination of Roxithromycin in tablets a rapid, and simple HPLC assay was developed. Reversed-phase chromatography was conducted using a RPC 18 (3.9 × 150 mm, 5 μm) and guard column RP C 18 (3.0 × 3.9 mm, 5 μm), mobile phase of 0.067 M phosphate buffer, pH 4.0 and methanol (65:35), and UV detection at 210 nm. Mean recovery of 100.90% and percentual coefficient of variation (CV%) of 1.51% was obtained from five commercial samples of Roxithromycin. The calibration graph was a straight line (r = 0.9995). Linearity is observed in the concentration range from 50.0 to 250.0 μg/ml. The excipients did not interfere in the determination.     

荧光光度法快速测定片剂中氨酰心安的含量

研究了氨酰心安的荧光光度法，其最大激发波长和荧光波长分别为２２２．３ｎｍ和２９７．４ｎｍ。该法灵敏度高，操作简便，氨酰心安浓度在０～３．００μｇ／ｍＬ范围内与相对荧光强度呈线性关系，相关系数为０．９９９７，检测限为０．０１６９μｇ／ｍＬ。该法用于测定片剂中氨酰心安含量，结果满意。     

Sensitive High-Performance Liquid Chromatographic Determination of Mebeverine in Plasma Using Fluorescence Detection

Abstract

A sensitive high-performance liquid chromatographic (HPLC) method for mebeverine (MB) determination in plasma is described. Sample preparation involves extraction of MB and Ibuprofen (internal standard) from 0.5 ml plasma. The analysis is carried out on reversed-phase chromatographic system using U-Bondapack C₁₈ column with a mobile phase consisting of water: acetonitrile:acetic acid (59:40:1) mixture. The effluent was monitored using a fluoremetric detection at excitation and emission wave lengths 270 and 362 nm, respectively. The method gave accurate, precise and reproducible results with high sensitivity. The within-day coefficients of variation ranged from 2.5 to 6.1% and between-days from 7.5 to 13.5% at four different concentrations. Injection-volumes containing as small amount of MB as 0.5 ng in plasma was detected. This method was applied to a bioavailability study with a single 10 mg/kg oral dose in two rabbits.     

High-Performance Liquid Chromatographic Method for the Simultaneous Determination of Four Flavonols in Food Supplements and Pharmaceutical Formulations

A method using high-performance liquid chromatography with diode array detection (HPLC-DAD) as a powerful separation technique has been developed for the simultaneous determination of the four flavonols rutin, quercetin, kaempferol and isorhamnetin in food supplements and pharmaceutical formulations. The chromatographic separation was achieved in 36?min using a Symmetry C₁₈ column (250?×?3?mm; 5?µm) as the stationary phase and a mixture of methanol, acetonitrile, and pH 2.5 aqueous acetic acid as the mobile phase in gradient elution mode. The analytical wavelengths were 256?nm for rutin, quercetin and isorhamnetin, and 368?nm for kaempferol. An ultrasound-assisted extraction protocol was performed using methanol as solvent. The detection and quantification limits were lower than 0.03?µg mL^?1 and 0.08?µg mL^?1, respectively. The inter-day and intra-day precisions were less than 4.8 and 5.1%, respectively, and the average recoveries were in the range from 96 to 107%. The method was applied for the determination of the studied flavonols in food supplements and pharmaceutical preparations. The satisfactory recovery values demonstrate the potential of the developed method for the determination of the analytes in these samples. In addition, the method is suitable for routine quality control due its ease of operation.     

Determination of Apomorphine in Tablets Using High Performance Liquid Chromatography with Electrochemical Detection

Abstract

A rapid and selective method using high performance liquid chromatography with electrochemical detection is described for the determination of apomorphine in tablets. Tablet mixes were dissolved in a standard volume of mobile phase containing the internal standard, N-n-propylnorapomorphine. Separation was achieved on a μ-phenyl column using methanol-acetonitrile-0.05M KH₂PO₄ (5:15:80) as mobile phase. The eluted compounds were detected with a sandwich-type electrochemical detector employing a glassy carbon working electrode and operated at 0.5V. Satisfactory accuracy and precision were obtained during analyses of tablets containing apomorphine.     

High-Performance Liquid Chromatographic Determination of Cinnarizine in Workplace Air

Summary Cinnarizine is a pharmaceutical drug used in the treatment of cerebral and peripheral vascular diseases. A reversed-phase liquid chromatographic method with fluorescence detection has been developed for determination of the drug in workplace air. Air sampling in the workplace is performed on perchlorovinyl filters (FPP), the filters are extracted with methanol for 40 min, and the extract (50 L) is injected and separated on a 250 mm × 4.6 mm i.d., 5 m particle, C₈ reversed-phase column with 1% ammonium acetate (pH 4.5)–acetonitrile, 1:4 (v/v), as mobile phase at a flow rate of 1 mL min^–1.     

Revised HPLC Determination of Atenolol in Plasma and Urine

Abstract

An HPLC method for analysis of atenolol in human plasma and urine is presented. Based on alkaline extraction, acid backextraction and reverse phase ion-pair chromatography this method is quite specific for atenolol. For a 0.5 ml plasma sample the sensitivity ranges from 20 ng/ml in fasted healthy volunteers to 50 ng/ml in various groups of patients. A sensitivity in urine of 1.0 mcg/ml was sufficient for all samples studied. As presented this method has been used in several clinical pharmacokinetic studies involving hundreds of samples.     

Simultaneous High-Performance Liquid Chromatographic Assay of Acetaminophen,Acetylsalicylic Acid,Caffeine, and D-Propoxyphene Hydrochloride

Abstract

A reversed phase high-performance liquid chromatography (HPLC) method for simultaneous measurement of acetaminophen (I), acetylsalicylic acid (II), caffeine (III) and d-propoxyphene (IV), using phenacetin (V) as an internal standard was developed. Using a 6.5 μ C-8 reversed phase column (RPP) with a mobile phase consisting of 0.01M sodium acetate solution: methanol (85:15%) at pH 4.1 enabled the Chromatographic separation of the four components in about 12 min. Quantitation was achieved by measuring the peak height ratio of each component relative to the internal standard. the validity of the developed method was tested by analyzing laboratory-prepared mixtures containing the four components in various proportions. Assay precision and sensitivity have been established for each component. the developed method proved to be stability-indicating as it can be applied to monitor salicylic acid as a degradation product in acetylsalicylic acid samples.     

High-Performance Liquid Chromatographic Determination of Progesterone

Abstract

A practical, rapid, reliable and isocratic reversed-phase HPLC method is described for the determination of progesterone; a method important for determining in cows (1) early pregnancy, (2) reproductive disorders, and (3) timing of artificial insemination. The method is reproducible with a detection limit of 0.5 ng/peak (400 pg/μl) at 254 nm (0.005 AUFS); down by nearly 10-fold from other methods and using simple 254 nm detection. Radioimmunoassay of all eluting fractions demonstrated specificity.     

Simultaneous Determination of Valsartan and Hydrochlorothiazide in Tablets by High-Performance Liquid Chromatography

ABSTRACT

A method for the simultaneous determination of valsartan and hydrochlorothiazide in tablets is described. The procedure, based on the use of reversed-phase high-performance liquid chromatography, is linear in the concentration range 5.0-10.0 μg ml^?1 for valsartan and 0.5-2.0 μg ml^?1 for hydrochlorothiazide, is simple and rapid and allows accurate and precise results. The limit of detection was 1.0 μg ml^?1 for valsartan and 0.05 μg ml^?1 for hydrochlorothiazide.     

Simultaneous Determination of Ibuprofen and Pseudoephedrine Hydrochloride in Pharmaceutical Tablets by Reversed-Phase HPLC

Abstract

An isocratic HPLC method was developed and validated for the simultaneous determination of ibuprofen (IBU) and pseudoephedrine hydrochloride (PSE). Chromatography was carried out on an Apex phenyl column using 0.025 M acetic acid, triethylamine solution (pH 4.5) – acetonitrile (80:20, v/v) as mobile phase at a flow rate of 1 mL · min^?1. UV detection was performed at a wavelength of 210 nm. The method was validated for specificity, linearity, accuracy, precision, and was successfully applied to pharmaceutical tablets of Rhinadvil®.     

Rapid High Performance Liquid Chromatographic Determination of Ampicillin in Human Urine

Abstract

A rapid, sensitive and specific HPLC assay for the determination of ampicillin in human urine is developed.

Ampicillin was directly measured in human urine at 225 nm using a reversed phase column (Synchropack RP-P) and a mobile phase composed of (1:9 methanol-sodium acetate solution, 0.01 M, pH 4). The analysis required no longer than 10 min. Linear correlation between the peak height ratio of ampicillin to cefoxitin sodium (internal standard) and ampicillin concentration in urine over the range 10–100 μg ml^?1 was obtained. The developed method proved to be advantageous as it monitors ampicillin level in urine. Moreover, the urinary excretion of ampicillin in human subjects after an oral administration of 500 mg ampicillin capsules was established using the proposed method.     

Simultaneous High-Performance Liquid Chromatographic and First-Derivative Spectrophotometric Determination of Amitriptyline Hydrochloride and Chlordiazepoxide In Capsules

Abstract

Rapid, precise, accurate and specific high-performance liquid chromatographic and first-derivative spectrophotometric procedures were described for the simultaneous analysis of amitriptyline and chlordiaze-poxide in two-component capsule formulations.

A reversed phase Micropack MCH-5 (CI8) column with a mobile phase composed of acetonitrile/water in a ratio (50:50) at pH3 and containing 0.01 M sodium-n-octane sulfonate separated amitriptyline, chlordiazepoxide and diazepam (internal standard). the drugs were detected at 230 nm at ambient temperature. the trough amplitudes in the first derivative spectrophotometric spectra at 245 nm and 282 nm were selected to determine amitriptyline and chlordiazepoxide.

Commercial capsules and laboratory-prepared mixtures containing both drugs in different proportions were assayed using the developed methods. the results were of comparable accuracy as indicated by the statistical analysis of data using t-test and F-test.     

High-Performance Liquid Chromatographic Determination of TCNB in Potatoes

Abstract

A high-performance liquid chromatographic (HPLC) method was developed for the determination of TCNB (tetrachloronitrobenzene), a sprout inhibitor, in potato peels and flesh fortified at levels of 0.16 to 53.5 ppm. TCNB was analyzed on a u Bondapak C₁₈ column with UV detection at 210 nm. The mobile phase was acetonitrile-methanol-water (35:35:30) at a flow rate of 1.0 ml/min. Retention time was approximately 10 min. TCNB was extracted by blending for 5 min in acetone. Samples at a level of 1 ppm or higher were directly injected whereas samples below 1 ppm were partitioned into hexane followed by passage through an alumina column. Average recoveries varied from 85.6 to 96.8% with coefficients of variation ranging from 2.18 to 11.68%. A study conducted to test 23 pesticides for possible interferences with TCNB demonstrated that none of them co-chromatographed. The lower limit of detection was 0.08 ppm.     

Simultaneous Determination of Atenolol,Rosuvastatin, Spironolactone,Glibenclamide and Naproxen Sodium in Pharmaceutical Formulations and Human Plasma by RP‐HPLC

A rapid and sensitive high‐performance liquid chromatographic method was developed and validated for the simultaneous determination and quantification of atenolol, rosuvastatin, spirnolactone, glibenclamide and naproxen sodium in bulk drugs, pharmaceutical formulations and in human plasma in the presence of internal standard (flurbiprofen). Chromatograms were developed with methanol and water (80:20, v/v) solvent system on a Purospher start, C₁₈ (5 μm, 250 × 4.6 mm) column and pH was adjusted to 3.40 with ortho‐phosphoric acid. Mobile phase was pumped with a flow rate of 0.90 mL/minute with 235 nm UV detection. Standard curves were linear over the concentration range 0.25‐30 μg/mL^?1. The coefficients of variation (C.V.%), were < 3% and LOD and LOQ were <0.0154 & 0.06 for inter‐ and intra‐day, respectively. The method was applied to drug interaction studies of atenolol with rosuvastatin, spironolactone, glibenclamide and naproxen to illustrate the scope and application of the methods to manage four different therapeutic classes of drugs, as they are co‐administered.     

Determination of Meloxicam in Tablet Formulations by Ultraviolet Spectrophotometry and High-Performance Liquid Chromatography

ABSTRACT

Assay procedures based on UV spectrophotometry and high-performance liquid chromatography (HPLC) have been developed for the determination of meloxicam in tablet formulations. The HPLC method used a reversed-phase C18 column with 0.05M Tris acetic acid buffer - tetrabutylammonium reagent–acetonitrile as eluent, and UV detection at 360nm with isoxicam as the internal standard. The UV method was based on measuring an acidic solution of the drug at 341nm. A comparison was established in terms of linearity, sensitivity, precision, and accuracy. Both methods were simple and rapid. HPLC was more precise and more accurate, the UV technique was slightly faster.     

Determination of Arteether in Plasma Using a Simple and Rapid High-Performance Liquid Chromatographic Assay

Abstract

A simple and rapid high-performance liquid chromatographic (HPLC) assay for the determination of the antimalarial drug arteether in plasma was developed and validated in this report. Perchloric acid was used in this method as a plasma protein precipitant and to attain an acidic medium suitable for the decomposition of arteether to a derivative possessing UV absorption. This derivative and the internal standard (progesterone) were separated from the plasma on a 10 μm μ-Bondapack C₁₈ reversed-phase column at ambient temperature with a mobile phase composed of acetonitrile:water (60:40 v/v) and at a flow rate of 1.5 ml/min. The effluent was monitored at 254 nm with a UV detector. Linear relation between drug concentrations and peak height ratios of arteether derivative to the internal standard was achieved in the range of 0.25-10 μg/ml arteether with a detection limit of 50 ng/ml arteether in plasma. The within-day and between-days precisions were evaluated using 3 different concentrations of arteether. The values of the coefficients of variation were 1.35-1.68% and 1.65-2.82% for within-day and between-day, respectively. This method was applied to determine some pharmacokinetic parameters of arteether after intramuscular injection of 50 mg/kg arteether oily solution to rabbits.     

High-Performance Liquid Chromatographic Determination of Isofraxidin in Rat Plasma

For the first time a high-performance liquid chromatographic (HPLC) method, with liquid-liquid extraction and ultraviolet (UV) absorbance detection, has been developed for quantification of isofraxidin in rat plasma. The analysis was performed on a Diamonsil C₁₈ column (200 mm × 4.6 mm i.d., 5 μm particle size) with acetonitrile–0.05% phosphoric acid, 26:74 (v/v), as isocratic mobile phase. The linear range was 0.05–8.0 μg mL⁻¹ and the lower limit of quantification was 0.05 μg mL⁻¹. The intra and inter-day relative standard deviation (RSD) for measurement of 0.25, 2.0, and 6.0 μg mL⁻¹ quality-control (QC) samples ranged from 5.7 to 6.4% and from 6.3 to 7.9%, respectively. Accuracy, as relative error (RE), was from ±5.8% to ±7.3%. The method was validated for specificity, accuracy, and precision and was successfully used in a pharmacokinetic study of isofraxidin in rat plasma after administration of Ciwujia extract.     

Reversed-Phase High-Performance Liquid Chromatographic Determination of Artemisitene in Artemisinin

Abstract

A new, simple and selective reversed-phase HPLC assay is developed for the determination of the clinically undesirable artemisitene in the antimalarial agent artemisinin (qinghaosu). It involves the use of an internal standard (santonin) and the determination time is less than 5 minutes. Detection was accomplished using a UV detector set at 216 nm and limits were as low as 15ng for a 10μl injection. Being simple and selective this method is particularly useful for the routine analysis of artemisinin to check its purity. In addition, the method can be used for preparative scale purification of these compounds. It has been applied for the evaluation of crystalline samples of artemisinin without prior preparation.     

High-Performance Liquid Chromatographic Determination of Iridoids in Cruciata Taurica

Abstract

The aerial and underground parts of Cruciata taurica (Pallas ex Willd.) Ehrend. s.l. (Rubiaceae) yielded three iridoids. Of these, Monotropein, Asperuloside and Aucubin. These compounds were separated and quantitated by reversedphase HPLC.