Liquid chromatography combined with electrospray ionization tandem mass spectrometry positive ion mode is used for the determination of glimepiride in human plasma. Gliclazide was used as the internal standard. The chromatographic separation was performed on a ACE 5 C18, 50 × 4 mm, 5 μm column at 30 °C with mobil phase consisting of 200 mL water, 450 mL acetonitrile, 350 mL methanol, 0.6 mL glacial acetic acid with a 0.5 mL min−1 flow rate. The work-up procedure involved a liquid–liquid extraction of the compounds. Mass spectrometric data were acquired in single ion monitoring of the ions 324.11 > 127.25 and 491.16 > 352.08 for glimepiride and gliclazide, respectively. The method was validated in the concentration range of 5–1,000 ng mL−1. Retention times of glimepiride and gliclazide were 1.65 and 1.36 min, respectively. The run time was 2.5 min. The method was found suitable to analyse human plasma samples for application in pharmacokinetic, pharmacodynamic, bioavailability/bioequivalance studies.
相似文献A reversed phase LC method was developed and validated to analyze the in vitro release of AZT from microemulsions. A mobile phase of acetonitrile:water (15:85) was used. The method validation showed good selectivity and linearity (r = 0.9993) for sample concentrations ranging from 0.6 to 100.0 μg mL−1. The RSD values (0.7–4.3%) and percentage recovery (88.1–109.8%) were within acceptable limits. The limit of detection (LOD) and limit of quantitation (LOQ) were found to be 0.012 and 0.041 μg mL−1. Quantitative analysis of the values obtained in the drug release assay indicates that the microemulsions used promote sustained release of AZT, which follows a Fickian diffusion mechanism.
相似文献An accurate, simple, reproducible, and sensitive liquid chromatographic method was developed and validated for the captopril determination in controlled release tablets. The analyses were performed at room temperature on a reversed-phase Phenomenex Luna C18 column (250 mm × 4.6 mm). The mobile phase was composed of water:methanol (45:55; v/v) pH 2.5, and it was eluted isocratically at a 1.0 mL min−1 flow rate. The method was validated in terms of specificity, linearity, quantification limit, detection limit, accuracy, precision and robustness. The response was linear in the range 0.3–1.5 mg mL−1 (r 2 = 0.9983). The relative standard deviation values for inter-and intra-day precision were 0.77% and 0.50%, respectively. Recoveries ranged between 97.7 and 99.1%. The method was successfully applied for the determination of captopril in the developed formulations.
相似文献A reliable liquid chromatographic method with photodiode array detector (DAD) was developed and validated for simultaneous separation and determination of five diester-diterpenoid alkaloids in the aconite roots. The separation was successfully performed on a Zorbax Extend-C18 column with a mobile phase gradient prepared from methanol and ammonia solution at a flow rate of 1.0 mL min−1. Good linearity (r > 0.999) was observed over the concentration ranges investigated, and intra-day and inter-day precision were high. The mean recoveries of five components ranged from 90.45 to 102.63% and relative standard deviations were always <5%. The validated method was successfully used for simultaneous determination of the five diester-diterpenoid alkaloids of unprocessed and processed aconite roots. The quantitative method provided a scientific basis for safety assurance and clinical application of aconite roots.
相似文献A new and accurate chiral liquid chromatographic method has been developed for the determination of enantiomeric purity of darifenacin [(S)-enantiomer] in bulk drugs and extended release tablets. Normal phase chromatographic separation was performed on an immobilized cellulose based chiral stationary phase (Chiralpak-IC) with n-hexane:ethanol:diethylamine (50:50:0.3, v/v/v) as mobile phase at a flow rate of 1.0 mL min−1. The elution time was ~15 min. The resolution (R s ) between the enantiomers was greater than four and interestingly the (R)-enantiomer was eluted prior to darifenacin in the developed method. The limit of detection (LOD) and limit of quantification (LOQ) for the (R)-enantiomer were 0.02 μg and 0.07 μg, respectively, for a 10 μL injection volume. The method was extensively validated in terms of linearity, precision and accuracy and satisfactory results were obtained. Robustness studies were also conducted. The sample solution stability of darifenacin was determined and the compound was found to be stable for a study period of 48 h.
相似文献A liquid chromatography method was developed and validated for the simultaneous determination of ezetimibe and simvastatin in pharmaceutical formulations. Optimum separation was achieved in less than 10 min using a C8 column (200 mm × 4.6 mm i.d., particle size 5 μm) and elution was accomplished by the application of a dual-mode solvent and flow-rate gradient system. Detection was carried out using a diode-array detector set at 240 nm. Canrenone was used as internal standard. The method was economical in terms of the time taken and the amount of solvent used for each analysis. It was also validated with respect to system suitability, specificity, limit of quantitation and detection, linearity, precision, accuracy, and recovery, respectively. The limits of quantitation for ezetimibe and simvastatin were 0.2 and 3 μg mL−1, respectively. Limits of detections were found to be 0.05 and 0.5 μg mL−1, for ezetimibe and simvastatin, respectively. The developed method was successfully applied to the simultaneous determination of ezetimibe and simvastatin in pharmaceutical formulations.
相似文献A simple, sensitive, and precise thin layer chromatographic (TLC) method for simultaneous analysis of psychopharmacological drugs like amitriptyline HCl, trifluoperazine HCl, risperidone and alprazolam in their single dosage forms has been developed, validated, and used for determination of the compounds in commercial pharmaceutical products. The TLC separation was carried out on Merck TLC aluminium sheets of silica gel 60 F254 using carbon tetrachloride:acetone:triethylamine (8:2:0.3, v/v/v), as mobile phase. Densitometric measurements of their spots were achieved at 250 nm over the concentration range for amitriptyline HCl (50–1,200 ng spot−1), trifluoperazine HCl (50–1,200 ng spot−1), risperidone (100–2,400 ng spot−1) and alprazolam (25–600 ng spot−1). Limit of detection (LOD) for amitriptyline HCl (20 ng spot−1), trifluoperazine HCl (20 ng spot−1), risperidone (40 ng spot−1) and alprazolam (5 ng spot−1) was obtained. The study showed that TLC was sensitive and selective for determination of amitriptyline HCl, trifluoperazine HCl, risperidone and alprazolam using a single mobile phase. This proposed method is able for simultaneous determination of psychopharmacological drugs and also applicable for analysis of pharmaceutical formulations.
相似文献A sensitive and specific liquid chromatography-tandem-mass spectrometry method was developed and validated for the simultaneous determination of clopidogrel and its carboxylic acid metabolite (SR26334) in human plasma using nateglinide and pioglitazone as internal standards. Analytes were extracted from 0.50 mL of plasma using diethyl ether–n-hexane (4:1, v/v). Chromatographic separation was performed on a Teknokroma C18 column with a mobile phase of methanol–water (containing 0.1% formic acid) (80:20, v/v) at a flow rate of 0.20 mL min−1 within 5.6 min. Linearity was established over the concentration range of 0.005–5 ng mL−1 for clopidogrel and 20–2,500 ng mL−1 for SR26334. Intra- and inter-batch standard deviations were less than 9.2% and the accuracy of this assay was found to fall within an acceptable range ≤10.0%. The method was successfully applied to the therapeutic drug monitoring of clopidogrel.
相似文献A simple, precise and reproducible liquid chromatography–tandem mass spectrometry method has been developed and validated according to the Food and Drug Administration guidelines for the simultaneous quantitation of antidiabetic drugs metformin, glimiperide and pioglitazone in human plasma using glipizide as an internal standard. Quantitation was performed on a triple quadrupole mass spectrometer employing electrospray ionization technique, operating in multiple reaction monitoring and positive ion mode. Inter-batch and intra-batch coefficient of variation across four validation runs for the quality control samples was less than 7%. The accuracy determined at quality control levels was within 92.81–105.13%. The method was applied to a bioequivalence study.
相似文献A capillary gas chromatography (GC) procedure has been developed for the determination of four pharmaceutical preparations (famotidine, ranitidine, cimetidine, and metformin) after precolumn derivatization with methylglyoxal (MGo). GC was carried out using an HP-5 column (30 m × 0.32 mm id) at an initial column temperature of 90 °C for 2 min, followed by heating rate of 25 °C min−1 up to 265 °C. Nitrogen flow rate was 2.5 mL min−1 with split ratio 10:1. A linear calibration curve was obtained within 50–1,000 ng mL−1 and the limit of detection (LOD) was within 17–25 ng mL−1. The derivatization, GC elution, and separation were repeatable in terms of retention time and peak height/peak area with relative standard deviation within ±4.6 %. The procedure was applied to the determination of the drugs in pharmaceutical preparations and the sera of volunteers who were given oral doses of the drugs. The results of the analysis agreed with the labeled values of the pharmaceutical preparations and were 147–4,903 ng mL−1 in serum with an RSD within 1.0–4.2 %, after ingestion of a single dose of 40–500 mg of active ingredient in a tablet.
相似文献A simple, fast and sensitive LC–MS/MS method was developed and validated for the simultaneous determination of the concentrations of temsirolimus and its major metabolite, sirolimus, in human whole blood. The blood sample (100 μL) after adding temsirolimus-d7 and sirolimus-d3 internal standards was precipitated with 0.200 mL of methanol/0.300 M zinc sulfate (70/30, v/v), then analyzed by a Shimatzu LC system coupled to a Sciex API-5000 mass spectrometer. The chromatographic separation was carried out on a BDS Hypersil C8 column (50 × 3.0 mm, 5 μm) at 50 °C with a mobile phase composed of methanol/water/formic acid (72/28/0.1) (v/v/v) containing 2.50 mM ammonium acetate. Mass spectrometric detection was performed using electrospray positive ionization with multiple reaction monitoring mode. This method was validated from 0.250 to 100 ng mL−1 for temsirolimus and 0.100 to 40.0 ng mL−1 for sirolimus. The lower limits of quantitation were 0.25 ng mL−1 for temsirolimus and 0.1 ng mL−1 for sirolimus. The intra-day and inter-day precisions (CV %) of spiked quality control (QC) samples were less than 10.4 and 9.6 %, respectively. The accuracies as determined by the relative error for QC samples were less than 12.1 % for intra-day and 7.3 % for inter-day. No significant matrix effect was observed. This method has been successfully applied to analyze clinical pharmacokinetic study samples. The assay reproducibility was also demonstrated by using incurred samples.
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