A reversed-phase liquid chromatography (RP-LC) method was validated for the determination of rupatadine in pharmaceutical dosage forms. The LC method was carried out on a Gemini C18 column (150 mm × 4.6 mm I.D.), maintained at 30 °C. The mobile phase consisted of ammonium acetate buffer (pH 3.0; 0.01 M) with 0.05% of 1-heptanesulfonic acid–acetonitrile (71.5:28.5, v/v), run at a flow rate of 1.0 mL min−1 and using photodiode array (PDA) detection at 242 nm. The chromatographic separation was obtained with retention time of 5.15 min, and was linear in the range of 0.5–400 μg mL−1 (r 2 = 0.9999). The specificity and stability-indicating capability of the method was proven through the degradation studies and showing also, that there was no interference of the excipients. The accuracy was 100.39% with bias lower than 0.58%. The limits of detection and quantitation were 0.01 and 0.5 μg mL−1, respectively. Moreover, method validation demonstrated acceptable results for precision, sensitivity and robustness. The proposed method was applied for the analysis of pharmaceutical dosage forms assuring the therapeutic efficacy.
相似文献In this work, a simple and rapid high-performance liquid chromatography coupled with charged aerosol detector (HPLC-CAD) method was first developed for the quantitation of toosendanin, the major constituent of the dried fruit of Melia toosendan Sieb. Et Zucc. Samples were well separated on an Agilent ZOBAX SB C18 column (4.6 mm × 250 mm, 5 μm) by isocratic elution using 33 % acetonitrile and 67 % water containing 0.1 % formic acid (v/v) at the flow rate of 1.0 mL min−1. The nitrogen inlet pressure of the charged aerosol detector (CAD) was 35 psi, and the nebulizer chamber temperature was 35 °C. The established method was well validated. Satisfactory linearity was achieved (r 2 > 0.9997) in a relatively wide concentration range (5–500 μg mL−1). The intra- and inter-day precisions, repeatability, and stability of the method were good with relative standard deviations (RSDs) of 1.05, 2.23, 2.39, and 2.03 %, respectively. The method also showed excellent accuracy with recovery rates of 97.42–101.87 %. Particularly, CAD showed much better sensitivity (LOQ 4 μg mL−1) than evaporative light scattering detector (LOQ 100 μg mL−1) for toosendanin’s determination. The established method was further applied in the quantitation of toosendanin in 39 batches of raw and stir-fried toosendan fructus. The HPLC-CAD method was rapid and accurate, and could be used for the routine analysis and quality control of toosendan fructus and its preparations.
相似文献A simple and sensitive method was developed for the determination of three nonsteroidal anti-inflammatory drugs (NSAIDs)—ibuprofen, naproxen and fenbufen in human plasma. The method involved in column liquid chromatographic separation and chemilumenescence (CL) detection based on the CL reaction of NSAIDs, potassium permanganate (KMnO4) and sodium sulfite (Na2SO3) in sulfuric acid (H2SO4) medium. The chromatographic separation was carried out using a reversed-phase C18 column, which allowed the selective determination of the three medicines in the complicated samples. The special features of the CL detector provided lower LOD for determination than that of existing chromatographic alternatives. The results indicated that the linear ranges were 0.01–10.0 μg mL−1 for ibuprofen, 0.001–1.0 μg mL−1 for naproxen, and 0.01–10.0 μg mL−1 for fenbufen. The limits of detection were 0.5 ng mL−1 for ibuprofen, 0.05 ng mL−1 for naproxen and 0.5 ng mL−1 for fenbufen (S/N = 3). All average recoveries were in the range of 90.0–102.3%. Finally, the method had been satisfactorily applied for the determination of ibuprofen, naproxen and fenbufen in human plasma samples.
相似文献A stability-indicating liquid chromatographic method was developed and validated for quantitative determination of olmesartan medoxomil (OLM) in coated tablets in the presence of degradation products generated under stress conditions. An isocratic LC separation was performed using a Phenomenex RP-18 column using a mobile phase consisting of water:triethylamine:acetonitrile (60:0.3:40 v/v/v, pH adjusted to 6.3 with phosphoric acid). The flow rate was 1.2 mL min−1 and the detection was achieved with a photodiode array detector set at 257 nm. The response was linear over a range of 10.0 to 30.0 μg mL−1 (r = 0.9999). The specificity and stability-indicating capability of the method was verified subjecting the reference substance and drug product to hydrolytic, oxidative, photolytic, and thermal stress conditions. The method showed a good and consistent recovery (100.2%) with low intra- and inter-day relative standard deviation (RSD) (≤1.0%). A considerable degradation occurred in all stress conditions and the degradation product was well resolved from the main peak. There was no interference of the excipients in the determination of the active pharmaceutical ingredient. Thus, the proposed method was found to be stability-indicating and can be used for routine analysis for quantitative determination of OLM in coated tablets without the interference of major degradation products.
相似文献A simple and mild method for the determination of fatty acids (C1 – C10) based on a condensation reaction using 7-aminonaphthalene-1,3-disulfonic acid (ANDSA) as labeling reagent with capillary zone electrophoresis has been developed. The detection was performed with a diode array detector at 254 nm. A 58.5 cm × 50 μm i.d. (50 cm effective length) untreated fused-silica capillary was used. To optimize the separation conditions, the background electrolyte concentration, column temperature, voltage and other factors were evaluated. The optimal separation conditions were as follows: 30 mmol L−1 borate buffer (pH 9.5), 15 mmol L−1 β-CD, temperature at 20 °C, pressure 50 mbar and injection time 8 s. Under the established conditions, 10 fatty acid derivatives could be well-separated within 17 min. The linearity was in the range of 0.07–5.0 μmol L−1. Detection limits (at a signal-to-noise ratio of 3) were in the range of 0.027–0.042 μmol L−1. The fatty acids from the extracted Funaria Hedw. and Selaginella samples were determined with satisfactory results.
相似文献A sensitive and simple HPLC method for simultaneous determination of PAC-1 (first procaspase-activating compound), phenol red, and permeability markers (carbamazepine and furosemide) in perfusion samples was developed and validated to assess intestinal absorption of PAC-1 using single-pass intestinal perfusion technique (SPIP) in rats. The chromatographic separation was carried out on a Kromasil C18 column (150 mm × 4.6 mm, 5 μm) with acetonitrile–methanol–30 mmol L−1 phosphate buffer (pH 3.0, 25:10:65, v/v/v) as mobile phase at a flow rate of 1.0 mL min−1, and the wavelength of the UV detector was set at 281 nm. The calibration curves were linear in the ranges of 2.40–48.0 μg mL−1 for PAC-1; 3.60–72.0 μg mL−1 for carbamazepine; 3.20–64.0 μg mL−1 for furosemide, and 4.80–96.0 μg mL−1 for phenol red (r > 0.999). Both the intra- and inter-day precisions (RSD%) of all analytes were less than 6.8 % at three concentration levels, while accuracy ranged from 95.4 to 104.5 %. Data obtained in all method validation studies indicated that the method was suitable for the intended purpose. The effective permeability values (P eff) considering water flux with the help of non-permeable marker phenol red was calculated to be 0.42 × 10−4, 0.62 × 10−4, 0.32 × 10−4 cm s−1 for PAC-1; 0.72 × 10−4, 0.77 × 10−4, 0.52 × 10−4 cm s−1 for carbamazepine; 0.20 × 10−4, 0.16 × 10−4, 0.12 × 10−4 cm s−1 for furosemide in duodenum, jejunum and ileum, respectively. The P eff value can be increased by co-perfusion with verapamil, indicating that absorption of PAC-1 is efficiently transported by P-glycoprotein (P-gp) in the gut wall.
相似文献Two chromatographic methods have been described for the simultaneous determination of metronidazole (MET) and spiramycin (SPY) in their mixtures. The first method was based on a high performance thin layer chromatographic (HPTLC) separation of the two drugs followed by densitometric measurements of their spots at 240 nm. The separation was carried out on Merck TLC aluminum sheets of silica gel 60 F254 using methanol: chloroform (9:1, v/v) as a mobile phase. Analysis data was used for the linear regression line in the range of 1.0–2.0 and 0.8–2.0 μg band−1 for MET and SPY, respectively. The second method was based on a reversed-phase liquid chromatographic separation of the cited drugs on a C-18 column (5 μm, 250 × 4.6 mm, i.d.). The mobile phase consisted of a mixture of phosphate buffer of pH 2.4 and acetonitrile (70:30, v/v). The separation was carried out at ambient temperature with a flow rate of 1.0 mL min−1. Quantitation was achieved with UV detection at 232 nm based on peak area with linear calibration curves at concentration ranges 0.4–50.0 and 0.5–50.0 μg mL−1 for MET and SPY, respectively. The proposed chromatographic methods were successfully applied to the determination of the investigated drugs in pharmaceutical preparations. Both methods were validated in compliance with ICH guidelines; in terms of linearity, accuracy, precision, robustness, limits of detection and quantitation and other aspects of analytical validation.
相似文献A rapid, sensitive, and specific reverse phase high performance liquid chromatography with diode array detection procedure for the simultaneous determination of abacavir, efavirenz and valganciclovir in spiked human serum is described. Separation was performed on a 5 μm Waters Spherisorb column (250 × 4.6 mm ID) with acetonitrile: methanol:KH2PO4 (at pH 5.00) (40:20:40 v/v/v) isocratic elution at a flow rate of 1.0 mL min−1. Calibration curves were constructed in the range of 50–30,000 ng mL−1 for abacavir and efavirenz, and 10–30,000 ngmL−1 for valganciclovir in serum samples. The limit of detection and limit of quantification concentrations of the HPLC method were 3.80 and 12.68 ng mL−1 for abacavir, 2.61 and 8.69 ng mL−1 for efavirenz, 1.30 and 4.32 ng mL−1 for valganciclovir. The method has been applied, without any interference from excipients or endogenous substances, for the simultaneous determination of these three compounds in human serum.
相似文献In this paper, we describe a compact and low-cost light-emitting diode-induced fluorescence (LED-IF) detection coupled to microchip electrophoresis for the determination of sulfonamides in pharmaceutical formulations and rabbit plasma. Three fluorescein isothiocyanate-labeled sulfonamides in rabbit plasma were separated in the running buffer of 40 mM phosphate buffer (pH 7.0) at the separation voltage of 2.0 kV, and detected by LED-IF detector in which the high-power blue LED was driven at the constant current of 150 mA and the emitted fluorescence over 510 nm was collected by a planar photodiode. The linear concentration ranged from 2.0 to 125.0 μg mL−1, both for sulfadiazine and sulfamethazine with the correlation coefficients (r 2) of 0.995 and 0.997, respectively, and from 2.0 to 100.0 μg mL−1 with the correlation coefficients (r 2) of 0.997 for sulfaguanidine. The limits of detection for the three sulfonamides were 0.36–0.50 μg mL−1 (S/N = 3). Intra-day and inter-day precision of migration time and peak area for the determination of sulfonamides were <4.5 %. This method has been successfully applied to the analysis of sulfonamides in pharmaceuticals, and could be used to study the pharmacokinetics of sulfonamides in rabbit.
相似文献Two new, rapid, precise, accurate and specific chromatographic methods were described for the simultaneous determination of olmesartan medoxomil and hydrochlorothiazide in combined tablet dosage forms. The first method was based on reversed phase liquid chromatography using an Eurosphere 100 RP C18 column (250 × 4.6 mm ID, 5 μm). The mobile phase was methanol–0.05% o-phosphoric acid (60:40 v/v) at a flow rate of 1.0 mL min−1. Commercially available tablets and laboratory mixtures containing both drugs were assayed and detected using a UV detector at 270 nm. The second method involved silica gel 60 F254 high performance thin layer chromatography and densitometric detection at 254 nm using acetonitrile–ethyl acetate–glacial acid (7:3:0.4 v/v/v) as the mobile phase. Calibration curves ranged between 200–600 and 125–375 ng spot−1 for olmesartan and hydrochlorothiazide, respectively.
相似文献Platycosides, main pharmacological effective compounds, are known to have several biological activities, including anti-obesity, anti-cancer and anti-diabetes. Although enzymatic preparation of platycosides was considered as effective method to obtain them, few analytical methods have been reported on process control. In the present study, we developed an application of reversed-phase high-performance liquid chromatography (RP-HPLC) method for simultaneous determination of six platycosides during the process of enzymatic preparation of deapio-platycodin D (dPD) and platycodin D (PD). The method employed a Hypersil ODS2 analytical column (250 × 4.6 mm I.D., 5 μm) coupled with UV detector at 210 nm with flow rate of 1.0 mg mL−1. A step gradient of acetonitrile–water (v/v) was applied, leading to a sample analysis of 60 min. The method was validated in terms of linearity, sensitivity, precision and accuracy. The correlation coefficients (R 2) for calibration curves of platycosides were in the range of 0.9995–1.0 when the linearity range was from 0.85 to 10.2 mg mL−1. The proposed RP-HPLC method was successfully applied to the analysis of enzymatic preparation study and the recoveries of platycosides were in the range of 96.22–102.56% with RSD <3.3%. The method could be of use for rapid and routine evaluation of the quantity of platycosides during the enzymatic preparation process.
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 new and fast high-performance liquid chromatography (HPLC) method using technology of fused-core columns for separation of fenoxycarb and cis-, trans-permethrin has been developed and used for their determination in antiparasitic veterinary shampoo. Separation of insecticides and internal standard sudan II was achieved on the fused-core column Ascentis Express RP-Amide (100 × 3.0 mm), particle size 2.7 μm, with mobile phase acetonitrile/water (55:45, v/v) at a flow rate of 1.0 mL min−1 and at temperature 60 °C. The detection wavelength of detector was set at 225 nm for both compounds and internal standard sudan II. Under the optimum chromatographic conditions standard calibration curves were measured with good linearity [r 2 = 0.99991 for fenoxycarb, r 2 = 0.99987 for trans-permethrin, and r 2 = 0.99984 for cis-permethrin (n = 8)]. Commercial samples of antiparasitic veterinary shampoo were extracted with ethanol in ultrasound bath for 5 min. A 2-μL sample volume of the filtered solution was directly injected into the HPLC system. Accuracy of the method defined as a mean recovery of insecticides from shampoo matrix was in the range 100.43–103.85 % for both insecticides.
相似文献In this study, a simple and efficient method has been developed to analyze pesticides in water samples using ultrasonic-assisted dispersive liquid–liquid microextraction (UA-DLLME) combined with gas chromatography-flame ionization detection (GC-FID). Several parameters, including type and volume of extractant and dispersant, extraction time, and amount of salt on extraction performance, were optimized in detail. A mixture of acetonitrile (1.0 mL, dispersant) and carbon tetrachloride (15 μL, extractant) was used for extraction. Under optimal conditions, enrichment factors were obtained between 315 and 1153. The linearity of the method ranged from 1 to 100 μg L−1 with correlation coefficients ≥0.9990. Limits of detection (S/N = 3) ranged between 0.09 and 0.57 μg L−1, depending on the compounds. Relative standard deviations were <8.0 % (n = 5) for both intra- and inter-day analyses. The proposed method was successfully applied for the preconcentration and determination of pesticides in water samples (river water, tap water, and lake water) with recoveries that varied from 90.5 to 107.7 %.
相似文献Two separation techniques were developed for the determination of S-(−)darifenacin (DAR) in the presence of its R-(+) isomer: The first method is high performance liquid chromatography (HPLC) and the second is capillary electrophoresis (CE). Chiral separation for chromatographic HPLC method development was carried out for S-DAR on Daicel CROWNPAK CR (+) (5 μm, 4.0 × 150 mm) column which contains (3,3-diphenyl-1,1-binaphthyl)-crown-6 coated onto a 5.5 μm silica support. The mobile phase system was aqueous acidic 70 % HClO4 (pH 2.5): methanol in the proportion of 90:10 v/v. This current mobile phase was delivered at flow rate 0.8 mL min−1 using UV detector adjusted at 286 nm. In CE method, the enantiomers were separated using 50 μm inner diameter fused-silica capillary cut to total lengths of 31.2 cm using 50 mM phosphate buffer as background electrolyte adjusted to pH 2.5 by triethanolamine. A wide range of cyclodextrins (CDs) were used such as highly sulfated α, γ CDs, hydroxyl propyl-β-CD and sulfobutyl ether-β-CD as chiral selectors. The effects of chiral additives regarding its concentration and content of organic modifier on the enantioseparation were investigated. Linear concentration ranges were from 2.5 to 50 and 40 to 300 μg mL−1 with detection limits 0.67 and 12.28 μg mL−1 for chromatographic HPLC and electrophoretic CE methods, respectively. The two methods were validated according to ICH guidelines with respect to linearity, accuracy, precision, LOQ, LOD and robustness. The suggested methods are suitable for separation and quantitation of S-DAR in tablets.
相似文献An LC-DAD method was developed for determination of lobeline from in vitro and in vivo cultures of Lobelia inflata. Samples were extracted with 0.1 N HCl–acetonitrile (1:1, v/v), and purified by solid-phase extraction. Optimized conditions resulted in high recovery. LC separations were performed on an Eurosphere C8 reversed-phase column using 30:70 (v/v) acetonitrile–0.1% trifluoroacetic acid as a mobile phase. Quantitative determination of lobeline was performed by external standard method at 250 nm, in the range of 2.4–80 μg mL−1. Validation studies proved that the repeatability of the method was good and the recovery was satisfactory. In vitro organized cultures contained considerable amount of lobeline (herb: 175 μg g−1, root: 100 μg g−1). When these cultures were transplanted into the open field, the lobeline content increased significantly (herb: 323 μg g−1, root: 833 μg g−1). Plants obtained from seed propagation contained 382 μg g−1 lobeline in the herb. For direct characterization of di-substituted piperidine alkaloids in extracts of L. inflata, tandem mass spectrometric method was developed using electrospray ionization. Analysis was performed in the positive ion mode on a triple quadropole LC–MS system. LC separations were achieved on Eurosphere C8 column with a modified mobile phase (acetonitrile–30 mM ammonium formate, pH 2.80) to ensure proper molecular ionization. The identification and structural elucidation of the alkaloids were performed by comparing their changes in molecular mass (ΔM), full-scan MS–MS spectra with those of lobeline, norlobelanine and lobelanidine. These alkaloids and ten other derivatives were identified in the plant extracts. Three piperidine alkaloids were reported in L. inflata for the first time.
相似文献This paper describes the validation of an isocratic LC method for the assay of linezolid in tablets. Validation parameters such as linearity, precision, accuracy, specificity, limit of detection, limit of quantitation and robustness were determined. LC was carried out by reversed phase technique on an RP-18 column with a mobile phase composed of 1% acetic acid:methanol:acetonitrile (50:25:25, v/v/v). Linezolid and your combination drug product were exposed to acid, base, oxidation, dry heat and photolytic stress conditions. A linear response (r > 0.9999) was observed in the range of 8.0–20.0 μg mL−1. The retention time of linezolid was 4.6 min. The method showed good recoveries and intra- and inter-day relative standard deviations were less than 1.0%. The LOD and LOQ were 0.21 and 0.63 μg mL−1, respectively. The developed LC method for determination of related substances and assay determination of linezolid can be used to evaluate the quality of regular production samples. It can also be used to test the stability samples of linezolid.
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, specific and sensitive liquid chromatographic method has been developed for the assay of ketorolac in human plasma and urine. The clean-up of plasma and urine samples were carried out by protein precipitation procedure and liquid–liquid extraction, respectively. Separation was performed by a Waters sunfire C18 reversed-phase column maintained at 35 °C. The mobile phase was a mixture of 0.02 M phosphate buffer (pH adjusted to 4.5 for plasma samples and to 3.5 for urine samples) and acetonitrile (70:30, v/v) at a flow rate of 1.0 mL min−1. The UV detector was set at 315 nm. Nevirapine was used as an internal standard in the assay of urine sample. The method was validated over the concentration range of 0.05–8 and 0.1–10 μg mL−1 for ketorolac in human plasma and urine, respectively. The limits of detection were 0.02 and 0.04 μg mL−1 for plasma and urine estimation at a signal-to-noise ratio of 3. The limits of quantification were 0.05 and 0.1 μg mL−1 for plasma and urine, respectively. The extraction recoveries were found to be 99.3 ± 4.2 and 80.3 ± 3.7% for plasma and urine, respectively. The intra-day and inter-day standard deviations were less than 0.5. The method indicated good performance in terms of specificity, linearity, detection and quantification limits, precision and accuracy. This assay demonstrated to be applicable for clinical pharmacokinetic studies.
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