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.
相似文献A HPLC and a HPTLC-densitometric method were developed for the quantification of prim-O-glucosylcimifugin and 4′-O-β-d-glucosyl-5-O-methylvisamminol the major chromone glucosides in the roots of Saposhnikovia divaricata. The validation of both methods resulted in comparable parameters regarding stability, specificity, linearity, robustness, precision and recovery, whereas complementary advantages were obtained concerning LOD and LOQ. The HPTLC-based densitometry revealed a lower LOD (1.11 versus 4.37 μg mL−1 in HPLC) and LOQ (3.36 versus 13.24 μg mL−1 in HPLC) for prim-O-glucosylcimifugin, whereas the HPLC resulted in a lower LOD (1.00 versus 4.10 μg mL−1 in HPTLC-densitometry) and LOQ (3.04 versus 12.46 μg mL−1 in HPTLC-densitometry) for 4′-O-β-d-glucosyl-5-O-methylvisamminol. Both methods revealed nearly matching contents of the chromones after analysis of different commercially available batches of Saposhnikoviae divaricatae radix with a total content for both chromone glycosides in the range from 0.31 ± 0.011 to 0.56 ± 0.021 % determined by HPLC and between 0.34 ± 0.011 and 0.61 ± 0.009 % determined by HPTLC. The plant material cultivated in Germany showed a very similar content and ratio of both chromone glucosides in comparison to the standard batches originating from China.
相似文献The objective of the current study was the development and subsequent validation of a simple, sensitive, precise and stability-indicating reversed-phase HPLC method for the determination of ciprofloxacin HCl in pharmaceutical dosage forms in the presence of its potential impurities. The chromatographic separation of ciprofloxacin HCl and its related compounds was achieved on an Inertsil ODS3 column using UV detection. The optimized mobile phase consisted of phosphoric acid solution: acetonitril. The proposed method provided linear responses within the concentration range 250–750 μg mL−1 for ciprofloxacin HCl and 0.5–1.5 μg mL−1 for its related compounds. LOD and LOQ values for the active substance were 5.159 and 15.632 μg mL−1, respectively. Correlation coefficients (r) of the regression equations for the impurities were greater than 0.99 in all cases. The precision of the method was demonstrated using intra- and inter-day assay RSD% values which were less than 1% in all instances. No interference from any components of pharmaceutical dosage forms or degradation products was observed.
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A simple RP-LC-UV method was established for the determination of tryptanthrin in plasma and different tissues of rats. The separation was achieved by HPLC on a C18 column with a mobile phases composed of acetonitrile–water (47:53, v/v), UV detection was used at 251 nm. Good linearity was found between 0.0183–1.1712 μg mL−1 (r 2 = 0.999) for plasma and 0.0937–1.7568 μg mL−1 for the tissue samples, respectively (r 2 ≥ 0.9932). The intra- and inter-day precisions expressed as the relative standard deviation for the method were 0.92–6.01 and 1.06–9.11 %, respectively. The relative recoveries of tryptanthrin ranged from 95.26 to 97.89 % for plasma and 82.55 to 114.99 % for tissue homogenates (except heart). The developed method was successfully applied to the pharmacokinetics and tissue distribution research after orally administration of a 56-mg kg−1 dose of tryptanthrin to healthy SD rats. The main pharmacokinetics distribution results showed that liver, lung, small intestine, and large intestine were the major distribution tissues of tryptanthrin in rats, and that tryptanthrin had difficulty in crossing the blood–brain barrier.
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 precise and sensitive LC method for determination of enantiomeric purity of trelagliptin has been developed and validated. Pre-column derivatization was performed before separation. Baseline separation with a resolution factor >2.5 was accomplished within 10 min by use of a Chiralpak AD column (250 × 4.6 mm; particle size 5 µm) and n-hexane–2-propanol (90:10 v/v) as mobile phase at a flow rate of 1 mL min−1. Eluted analytes were monitored by UV detection at 260 nm. The effects of mobile phase composition and temperature on enantiomeric selectivity and on resolution of enantiomers were thoroughly investigated. Calibration curves were plotted within the concentration range 0.005–2 mg mL−1 (n = 12), and recoveries between 98.23 and 101.34 % were obtained, with relative standard deviation (RSD) <1.39 %. LOD and LOQ for the trelagliptin derivative were 1.51 and 5.03 µg mL−1; those for its enantiomer were 1.49 and 4.94 µg mL−1, respectively. The method was evaluated and validated by analysis of bulk samples of trelagliptin of different enantiomeric purity. It was demonstrated that the method was accurate, robust, and sensitive, and enabled practical analysis of real samples.
相似文献A suitable method that allows, for the first time, the simultaneous determination of nine antibiotics which may help the therapy of acne vulgaris by rapid liquid chromatography with diode array detection in 7 min is presented in this work. An SB RP18 (50 × 4.6 mm; 1.8 μm particle size) column was used with the mobile phase consisting of a mixture of 0.1 mol L−1 potassium dihydrogen phosphate (pH 2.5) and acetonitrile at the gradient elution program. The correlation coefficients were all above 0.9999 in the linear range between 4–100 μg mL−1, the average spiked recoveries (n = 6) were 92.2–103.2% with RSD ranging from 0.04 to 4.5% depending on the target analytes. The method detection limits were in the range of 0.02–0.2 μg mL−1 in anti-acne cosmetics. The analysis of real cosmetic preparations demonstrated the fitness for the whole analytical procedure. The proposed method appeared therefore as a sound alternative for official testing method, which could overcome the general problems of time consuming, lack of the specificity and precision difficulty.
相似文献A precise and sensitive LC method for the determination of repertaxin enantiomeric purity has been developed and validated. Baseline separation with a resolution higher than 2.0 was accomplished within 20 min using a Chiralpak AD-H column (250 × 4.6 mm; particle size 5 μm) and n-hexane:2-propanol (90:10 v/v) as mobile phase at a flow rate of 1 mL min−1. Eluted analytes were monitored by UV detection at 260 nm. The effects of mobile phase composition, temperature and flow rate on enantiomeric selectivity and on resolution of enantiomers were investigated. Calibration curves were plotted within the concentration range between 0.002 and 1.0 mg mL−1 (n = 3), and relative standard deviation (RSD) of the inter-batch assay and intra-batch assay was less than 1.27 and 1.16 %. LOD and LOQ for repertaxin were 0.65 and 2.19 μg mL−1; those for its enantiomer were 0.70 and 2.34 μg mL−1, respectively. The method was evaluated and validated by analysis of bulk samples of repertaxin of different enantiomeric purity. It was demonstrated that the method was accurate, robust, and sensitive, and enabled practical analysis of real samples.
相似文献An efficient, high-performance liquid-chromatographic method with diode-array detection (HPLC–DAD) has been established for simultaneous determination of retinol, α, (β + γ), and δ-tocopherols, and α, β, γ, and δ-tocotrienols in human serum. After deproteinization, the target vitamins in serum were extracted with n-hexane and the extract was evaporated under weak nitrogen flow. The residue was redissolved in methanol and the resulting solution was used for HPLC analysis. Retinol acetate and α-tocopherol acetate were used as internal standards. The internal standard calibration curves were linear over the range of 0.010–50.0 µg mL−1, with correlation coefficients >0.999. Mean recoveries of the method were 86.3–110 %, with intra-day and inter-day relative standard deviations less than 12.2 and 14.9 %, respectively. The detection limits of the method ranged from 0.001 to 0. 002 µg mL−1, and the quantification limits ranged from 0.002 to 0.008 µg mL−1. The method was successfully applied to analysis of the target vitamins in 50 human serum samples; all the analytes were detected at concentrations ranging from <0.002–23.0 µg mL−1.
相似文献A simple, stability-indicating, reversed-phase liquid chromatographic method was developed for the determination of lacidipine in the presence of its degradation products. The analysis was carried out using a 150 mm × 4.6 mm i.d., 5 μm particle size Nucleodur MN-C18 column. Mobile phase containing a mixture of acetonitrile and 0.02 M phosphate buffer (70:30) at pH = 5.0 was pumped at a flow rate of 1 mL min−1 with UV-detection at 254 nm. The method showed good linearity in the range of 0.06–15 μg mL−1 with a limit of detection (S/N = 3) of 0.016 μg mL−1 (3.5 × 10−8 M). The suggested method was successfully applied for the analysis of lacidipine in bulk and in commercial tablets with average recoveries of 100.19 ± 0.81% and 100.05 ± 0.69%, respectively. The results were favorably compared to those obtained by a reference method. The suggested method was utilized to investigate the kinetics of alkaline, acidic, peroxide and photo-induced degradation of the drug. The apparent first-order rate constant, half-life times and activation energies of the degradation process were calculated. The pH profile curve was derived. The proposed method was successfully applied to the content uniformity testing of tablets.
相似文献A new HPLC method based on a mixed mode stationary phase Hypersil Duet C18/SAX was developed and applied for the simultaneous determination of acetaminophen, acetylsalicylic acid and codeine. Parameters, such as the composition of the mobile phase, the nature of the organic modifier, the buffer type and the flow rate were investigated to optimize the separation. The results obtained show that the new HPLC method is rapid, highly efficient and selective. The studied compounds are separated in 10 min, by means of a mobile phase containing phosphate buffer (pH 7.50) and methanol (65:35 v v−1). The retention mechanisms of each analyte were investigated using both the linear solvent strength theory and stoichiometric displacement model. The method was fully validated and showed good linearity for each compound for a concentration ranging between 2.0 and 40 μg mL−1. The limits of detection and quantification were determined and they are lower than 0.1 μg mL−1. The precision (RSD) of the method does not exceed 2 % for all studied compounds. The method was successfully applied for the assay of acetaminophen, acetylsalicylic acid and codeine in pharmaceutical formulations.
相似文献A simple, rapid, and reproducible isocratic reverse-phase HPLC method was developed to simultaneously determine AKF-PD and its two oxidized metabolites in rat plasma. 5-Carboxyl-1-phenyl-2-(1H)-pyridone and phenacetin were used as internal standards to ensure the precision and accuracy of the method. The analytes were separated on a C18 reversed-phase column with methanol—phosphate buffer (20 mM, pH 2.5) as mobile phase. The limits of detection for AKF-PD and its two oxidized metabolites was 0.1 μg mL−1. The method is applicable for the pharmacokinetic studies of AKF-PD and its metabolites in rats.
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.
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