A simple stability-indicating reversed-phase liquid chromatographic method with diode-array detection was developed and validated for the quantitative determination of ebastine in tablets and syrup. The LC method was carried out on a C18 column with acetonitrile:phosphoric acid 0.1% pH 3.0 (55:45, v/v) as mobile phase, at a flow rate of 1.2 mL min−1. Ultraviolet detection of ebastine was at 254 nm. A linear response (r = 0.9999) was observed in the range of 10–80 μg mL−1. The RSD values for intra- and inter-day precision studies showed good results (RSD < 2%) and accuracy was greater than 98%. Validation parameters such as specificity and robustness were also determined. The method was found to be stability-indicating and can be applied to quantitative determination of ebastine in tablets and syrup.
相似文献A simple, rapid, sensitive and selective LC-MS method was developed and validated for quantification of fexofenadine in human plasma. The LC-MS system was operated under the positive electrospray ionisation mode (ESI). After liquid–liquid extraction, fexofenadine analysis was performed on a C18 column with a mobile phase of acetonitrile: 10 mM ammonium acetate: formic acid, 70:30:0.1 (v/v/v) at a flow rate of 1 mL min−1 by using loratadine as internal standard. The lower limit of quantitation was 3 ng mL−1 for fexofenadine. The assay precision ranged between 1.05 and 12.56% and accuracy ranged between 82.00 and 109.07%. The validated method was successfully used to analyze human plasma samples in bioequivalence studies.
相似文献Dimenhydrinate (DM) is used therapeutically for the prevention of motion sickness associated with nausea and vomiting. The aim of this investigation is the development of a new, rapid, sensitive, simple and fully validated RP-LC procedure for the suitable assay of DM in pharmaceutical formulation applied in blood samples. The method was validated before the amount determination studies in order to confirm linearity, precision, accuracy, selectivity, determination and quantification limit and consistency. High determination coefficient (r 2 = 0.998) of the standard curve drawn in the linearity studies showed that the line equation can be used in the quantification of the DM. Literature was reviewed for the methods based on diphenhydramine (DIP), its metabolite dimenhydrinate, in the in vivo determination of dimenhydrinate amount. The most appropriate method to be used in LC was decided to be the method applied by benefitting from the fluorescence characteristic of DIP. Maximum excitation and emission wavelengths in the developed method were scanned using multiple wavelengths and, maximum excitation and emission wavelengths were found to be 215 and 300 nm, respectively. In the validation study used to prove validity of the method, determination coefficient of the developed standard curve was calculated as 0.998 (RSD %), and line equation was concluded to be appropriate for use in amount determination studies. BBS % (1.06, 1.84 %) values obtained as “<2 %” in the intra-day and inter-day precision studies proved the precision of the method. Selectivity study revealed that other materials used in the formulation did not exhibit absorbance in the same wavelengths. Detection and quantification limit were found as 1 and 5 ng mL−1, respectively. The determination of DM plasma concentrations using the proposed and fully validated LC assay has allowed us to characterize DMPK in the sheep, as well as determine DM relative bioavailability.
相似文献A simple method for the determination of carbamazepine and its active metabolite carbamazepine-10,11-epoxide by ultra performance liquid chromatography (UPLC) with ultraviolet absorbance detection (TUV) was developed. The method involves a two-step protein precipitation by liquid–liquid extraction. Phenytoin sodium was used as the internal standard. The separation was carried out on Acquity C18 column with acetonitrile:methanol:KH2PO4 buffer (adjusting pH to 4.6 with 85% o-phosphoric acid) (180/180/170, v/v/v) as the mobile phase at a flow rate of 0.4 mL min−1. Linear detection response was obtained for concentrations ranging from 50 to 5,000 ng mL−1. The limit of quantification (LOQ) was 50 ng mL−1. The method was validated successfully for the determination of carbamazepine and its active metabolite carbamazepine-10,11-epoxide, which can be applied through pharmacokinetics and bioequivalence studies.
相似文献An UPLC method for determination of allicin in garlic bulb powder has been developed and validated. Chromatographic separation and determination were performed on an Acquity UPLC BEH C18 column using a mobile phase of methanol/water (50:50, v/v). Linearity between the allicin concentration and the peak area was good within the concentration ranges 2.04–510 mg L−1. The method was validated over this range for both accuracy and precision. The method was successfully used for the quantitative analysis of allicin in ten garlic varieties.
相似文献A simple, suitable reverse phase liquid chromatographic method was developed for simultaneous determination of andrographolide (1) and dehydroandrographolide (2) in chicken plasma after orally administrating the ultra-fine powder of Andrographis paniculata. Plasma samples were extracted with ethyl acetate. Analysis of the extract was performed on a reversed-phase C18 column with gradient eluent composed of acetonitrile and 0.5% acetic acid. The flow rate was kept at 1 mL min−1 and the detection wavelength was set at 225 and 255 nm for 1 and 2, respectively. All calibration curves showed good linear regression (R ≥ 0.9991). The good precision and recoveries with intra-day and inter-day were 3.2–8.7% and 91.1–98.4%, respectively. The limit of detection was 0.016 µg mL−1 and the limit of quantitation was 0.040 µg mL−1 for the target analytes. This validated method has been successfully applied in the pharmacokinetics study of 1 and 2 after orally administrating the Andrographis paniculata ultra-fine powder to chicken.
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 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ent-11α-Hydroxy-15-oxo-kaur-16-en-19-oic acid (5F), a diterpenoid isolated from the Chinese herb Pteris semipinnata L, has been suggested to show antitumor properties. A simple and sensitive LC method was developed for the determination of 5F in rabbit plasma. The method involved liquid–liquid extraction using ethyl acetate under acidic conditions using naproxen as an internal standard. Separations were performed on a reversed-phase column with a mixture of 1% (v/v) glacial acetic acid and methanol (45:55, v/v) as mobile phase and UV detection was utilized at 242 nm. The calibration plot was linear in the range 0.20–10.0 μg mL−1 (correlation coefficients r 2 > 0.998). The detection limit was 0.20 μg mL−1, mean extraction recovery was above 82%, intra-day precision of the method was less than 6.4%, and inter-day precision was better than 8.7%, respectively. The validated assay was found to be suitable for the pharmacokinetic study of 5F in rabbits.
相似文献A sensitive high performance liquid chromatographic method has been developed and validated for the determination of proparacaine in human aqueous humour. The procedure involved extraction of proparacaine from aqueous humour with cyclohexane. The separation was achieved using a Bondesil C8 (250 × 4.6 mm i.d., particle size 5 μm) analytical column with a mobile phase consisted of acetonitrile and sodium dihydrogen phosphate (pH 3.0, 20 mM) (30:70, v/v). Proparacaine and lidocaine (internal standard, IS) detection was performed by UV–Vis detector at 220 nm. The retention times for proparacaine and IS were 12.01 and 5.58 min, respectively. HPLC–UV–Vis method was linear in the range of 75–4,000 ng mL−1. The limit of detection (LOD) was 25 ng mL−1 and the limit of quantification (LOQ) of proparacaine was found to be 75 ng mL−1 (RSD ≤ 15%, n = 6). In intra- and inter-day precision and accuracy analysis, the relative standard deviation was found to be in the range of 0.96 and 7.98%, the bias values were 0.64 and 3.33%. Recovery of proparacaine from human aqueous humour was 99.98% at 500 ng mL−1. Proparacaine solutions were stable at least 6 months at +4 and −20 °C. Proparacaine levels of aqueous humour in fifteen volunteers’ were in the range of 80.21 and 459.00 ng mL−1. According to system suitability tests and Shewhart’s quality control charts the proparacaine responses were in the acceptance ranges. Developed method was providing a sufficient quality at least over 3 months for determination of proparacaine in human aqueous humour.
相似文献A CZE method was developed and validated for the analysis of Olmesartan medoxomil (OLMD) in tablets. The influences of pH, buffer concentration, applied voltage and capillary temperature on the migration time of OLMD were investigated. About 50 mM pH 6.5 phosphate buffer were used as background electrolyte. The optimum instrument parameters were found to be 30 °C temperature with 30 kV applied voltage and diode array detection was carried out at 210 nm. OLMD was hydrodynamically injected (P inj = 50 mbar, t inj = 3 s) and an internal standard, diflunisal (IS), was used to improve the precision and repeatability. Under these conditions, the migration time of OLMD was 2.32 min and the total analysis time was shorter than 5 min. Linearity range for the developed method was found to be 2.0–50.0 μg mL−1 and the limit of detection was 0.5 μg mL−1. The developed method was applied for the analysis of OLMD in pharmaceutical tablet formulations.
相似文献A new, sensitive and stability indicating liquid chromatographic method has been developed for the determination of imatinib mesylate (IM). Efficient chromatographic separation was achieved using a C18 column with simple mobile phase combination delivered in an isocratic mode and quantitation was carried out using ultraviolet detection. For the first time, a novel microwave assisted degradation procedure was employed for stress testing studies. In addition, orthogonal separation technique was applied to demonstrate selectivity of the proposed method. The method has demonstrated excellent linearity over the range of 25–1,600 ng mL−1. Moreover, the method was found to be sensitive with a low limit of detection (3.35 ng mL−1) and limit of quantitation (10.16 ng mL−1). The method has shown good and consistent recoveries (99.35–100.69%) with low intra- and inter-day relative standard deviation (RSD) (<2.5%). Experimental design confirmed that peak area was unaffected by small changes in critical factors, in robustness study. The validated method was successfully applied for determination of IM in pharmaceutical formulations.
相似文献A new and simple high-performance liquid chromatography with evaporative light scattering detector method for the determination of Kryptofix 2.2.2 (K-222) in the radiopharmaceuticals of 2-deoxy-2-[18F]fluoro-d-glucose ([18F]FDG) and 3′-deoxy-3′-[18F]fluorothymidine ([18F]FLT) was developed. A C18 column was used and the mobile phase was 10 % (v/v) methanol and 90 % (v/v) water (0.1 % trifluoroacetic acid, v/v) at a flow rate of 0.2 mL min−1. The drift tube temperature was 40 °C. The pressure of nebulizing gas (N2) was 3.0 bar. The gain was 10. Good separation of K-222 from main related substances could be achieved. Excellent linearity (r 2 = 0.9995) was obtained over the range of 5–100 μg mL−1. The precision ranged from 0.68 to 5.16 % (RSD) and the accuracy ranged from −3.05 to 2.62 % (RE). The limit of detection was 2 μg mL−1. This method offers simple, rapid and quantitative detection of K-222, thus making it acceptable for routine determination.
相似文献A rapid and specific high-performance liquid chromatographic method coupled with electrospray ionization mass spectrometric detection has been developed and validated for identification and quantification of wogonin and oroxylin A in rat plasma. Wogonin, oroxylin A, and diazepam (internal standard) were extracted from plasma samples by liquid–liquid extraction with ethyl acetate. Chromatographic separation was achieved on a C18 column with acetonitrile–0.6% aqueous formic acid 35:65 (v/v) as mobile phase at a flow rate of 0.2 mL min−1. Detection was performed with a single-quadrupole mass spectrometer in selected-ion-monitoring (SIM) mode. Linearity was good within the concentration range 14.4–360 ng mL−1 for wogonin and 10.8–271 ng mL−1 for oroxylin A; the correlation coefficients (r 2) were 0.9999. The intra-day and inter-day precision, as RSD, was below 12.4%, and accuracy ranged from 81.1 to 111.9%. The lower limit of quantification was 14.4 ng mL−1 for wogonin and 10.8 ng mL−1 for oroxylin A. This method was successfully used in the first pharmacokinetic study of wogonin and oroxylin A in rat plasma after oral administration of the active fraction from Xiao-xu-ming decoction.
相似文献A sensitive and selective method for determination of (S,R)-penehyclidine in rat plasma by liquid chromatography-tandem mass spectrometry is described. The procedure employed the use of an internal standard (I.S.) and a simple protein precipitation step. The method developed was linear from 0.1 to 100 ng mL−1, with a sensitivity of 0.1 ng mL−1 as the lower limit of quantification. The intra- and inter-day assay accuracy (relative error) was within 8.27% and precision (RSD) was below 6.7%. It was successfully applied to pharmacokinetic studies of (S,R)-penehyclidine in rat plasma.
相似文献A stereoselective liquid chromatographic method to determine the enantiomers of ornidazole in human plasma and urine has been developed and validated. After addition of the internal standard (naproxen), samples were acidified and extracted with diethyl ether. The separation was performed on a Chiralcel OB-H column, using hexane-ethanol- glacial acetic acid (94:6:0.08, v/v) as the mobile phase. The method was validated for specificity, linearity, sensitivity, precision, accuracy and stability. For each enantiomer of ornidazole, linear calibration curves were obtained over the concentration range of 0.16–20 μg mL−1 in plasma and 0.32–20 μg mL−1 in urine. For both enantiomers of ornidazole in plasma and urine, the coefficient of variation for precision were consistently less than 12% and accuracy were within ±14% in terms of relative error. Application of the method to a preliminary pharmacokinetic study showed that this validated method was qualified for the direct determination of ornidazole enantiomers in human plasma and urine.
相似文献An LC method was developed for determination of mangiferin in rat plasma and tissues after oral administration of Rhizoma Anemarrhenae extract. Analysis was performed on a Gemini C18 analytical column (250 × 4.6 mm, i.d.) with mobile phase consisting of acetonitrile–water (23:77, v/v) with 1% acetic acid and 1% tetrahydrofuran at a flow rate of 0.7 mL min−1. Spinosin was used as internal standard and UV detector was set at 320 nm. The calibration curve of mangiferin in rat plasma and tissues showed excellent linear behaviors over the investigated concentration ranges with the value of R 2 higher than 0.994. The within-day and between-day precisions for all samples were measured to be below 11.0%. The limit of quantitation was low enough for determination of mangiferin in all samples. After Rhizoma Anemarrhenae extract was orally administered to rats, the main pharmacokinetic parameters of mangiferin T max, C max, T 0.5α , T 0.5β , AUC0 − T and Vc were 4.20 h, 9.52 μg mL−1, 1.21 h, 1.71 h, 29.9 mg h L−1 and 0.18 L kg−1, respectively. Mangiferin was extensively distributed in most of the main tissues of rats. This validated method has been successfully applied to preliminary pharmacokinetics and tissue distribution study of mangiferin in rats.
相似文献An accurate, simple, reproducible, and sensitive method for determination of rosmarinic, caffeic, chlorogenic, and gallic acids in 12 Salvia species growing naturally in Anatolia, has been developed and validated. The phenolic acids were separated using a μBondapack C18 column by gradient elution with a flow rate of 1.0 mL min−1, which was adjusted to deliver firstly o-phosphoric acid 0.085% in water, 0.085% in methanol, and 0.085% in 2-propanol (80:10:10, v/v/v), then decreased gradually (60:20:20, v/v/v) during 20 min with a flow rate of 1.0 mL min−1. The samples were monitored at 220 nm for gallic acid and 330 nm for rosmarinic, caffeic, and chlorogenic acids using photo-diode array detection. The linear range of detection for gallic, chlorogenic, caffeic, and rosmarinic acids were between 0.051–101.4, 0.207–103.6, 0.100–100, and 0.201–100.5 μg mL−1, respectively. The linearity, range, peak purity, selectivity, system performance parameters, precision, accuracy, and robustness had also acceptable values. The developed method was applied to the flower, leaf, stem, and root parts of the Salvia species.
相似文献A selective and highly sensitive high performance liquid chromatography-electrospray ionization mass spectrometry method has been developed for determination of ezetimibe concentrations in human plasma. Ezetimibe was extracted from plasma with ethyl acetate followed by evaporation of the organic layer and, then, reconstitution of the residue in mobile phase before injection to chromatograph. The mobile phase consisted of acetonitrile-ammonium acetate (10 mM, pH 3.0), 75:25 (v/v). An aliquot of 10 μL was chromatographically analyzed on a prepacked Zorbax XDB-ODS C18 column (2.1 × 100 mm, 3.5 micron). Detection of analytes was achieved by mass spectrometry with atmospheric pressure chemical ionization (APCI) interface in the negative ion mode operated under the multiple-reaction monitoring mode (m/z transition: ezetimibe 408–271). Standard curves were linear (r = 0.998) over the wide ezetimibe concentration range of 0.05–30.0 ng mL−1 with acceptable accuracy and precision. The limit of detection was 0.02 ng mL−1. The validated LC–APCI–MS method has been used successfully throughout a bioequivalence study on an ezetimibe generic product in 24 healthy male volunteers.
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