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1.
Rahul P. Dixit Chandrashekhar R. Barhate Mangal S. Nagarsenker 《Chromatographia》2008,67(1-2):101-107
Simvastatin and ezetimibe are used to treat hyperlipidemia. A simple, selective and stability-indicating HPTLC method has
been established for analysis of simvastatin and ezetimibe. The method has been validated so that both drugs can routinely
be analyzed simultaneously. The method uses aluminum-backed silica gel 60F254 TLC plates as stationary phase with n-hexane–acetone 6:4 (v/v) as mobile phase. Densitometric analysis of both drugs was carried out in absorbance mode at 234 nm. This system was found
to give compact bands for simvastatin and ezetimibe (R
F 0.39 ± 0.05 and 0.50 ± 0.05, respectively). Linear relationships were obtained between response and amount of drug in the
range 200–1,600 ng per band with high correlation coefficients (r
2 = 0.9917 ± 0.0018 for simvastatin and r
2 = 0.9927 ± 0.0021 for ezetimibe). The method was validated for precision, robustness, and recovery. The limits of detection
and quantitation were 25 and 150 ng per band, respectively. Simvastatin and ezetimibe were subjected degradation by acid,
pH 6.8 phosphate buffer, oxidation, dry heat, and wet heat. The degradation products were well resolved from the pure drug
with significantly different R
F values. Because the method could effectively separate the drug from its degradation products, it can be used for stability-indicating
analysis. 相似文献
2.
A simple, precise, and accurate HPLC method has been developed and validated for assay of ezetimibe in tablets and for determination
of content uniformity. Reversed-phase liquid chromatographic separation was achieved by use of phosphoric acid (0.1%, v/v)–acetonitrile 50:50 (v/v) as mobile phase. The method was validated for specificity, linearity, precision, accuracy, robustness, and solution stability.
The specificity of the method was determined by assessing interference from the placebo and by stress testing of the drug
(forced degradation). Response was a linear function of drug concentration in the range 20–80 μg mL−1 (r = 0.9999). Intraday and interday system and method precision were determined. Accuracy was between 100.8 and 102.7%. The
method was found to be robust, and was suitable for assay of ezetimibe in a tablet formulation and for determination of content
uniformity.
An erratum to this article can be found at 相似文献
3.
Samir Mohamed El‐Moghazy Mohamed Abd El‐Azem Mohamed Marwa Fadel Mohamed Nadia Fayek Youssef 《中国化学会会志》2009,56(2):360-367
Reversed phase‐high performance liquid chromatography (RP‐HPLC), thin layer chromatography (TLC) densitometry and first derivative spectrophotometry (1D) techniques are developed and validated as a stability‐indicating assay of ezetimibe in the presence of alkaline induced degradation products. RP‐HPLC method involves an isocratic elution on a Phenomenex Luna 5μ C18 column using acetonitrile: water: glacial acetic acid (50:50:0.1 v/v/v) as a mobile phase at a flow rate of 1.5 mL/min. and a UV detector at 235 nm. TLC densitometric method is based on the difference in Rf‐values between the intact drug and its degradation products on aluminum‐packed silica gel 60 F254 TLC plates as stationary phase with isopropanol: ammonia 33% (9:1 v/v) as a developing mobile phase. On the fluorescent plates, the spots were located by fluorescence quenching and the densitometric analysis was carried out at 250 nm. Derivative spectrophotometry, the zero‐crossing method, ezetimibe was determined using first derivative at 261 nm in the presence of its degradation products. Calibration graphs of the three suggested methods are linear in the concentration ranges 1–10 mcg/mL, 0.1–1 mg/mL and 1–16 mcg/mL with a mean percentage accuracy of 99.05 ± 0.54%, 99.46 ± 0.63% and 99.24 ± 0.82% of bulk powder, respectively. The three proposed methods were successfully applied for the determination of ezetimibe in raw material and pharmaceutical dosage form; the results were statistically analyzed and compared with those obtained by the reported method. Validation parameters were determined for linearity, accuracy and precision; selectivity and robustness and were assessed by applying the standard addition technique. 相似文献
4.
A new, specific and sensitive GC‐MS method with electron impact ionization technique was developed for quantitative analysis of ezetimibe (EZE) in human plasma. Prior to GC analysis, EZE was derivatized with N‐methyl‐N‐trimethylsilyl‐trifluoroacetamide (MSTFA), which is a trimethyl silylating reagent. The derivatization reaction was optimized and parameters such as catalyst, derivatization time, temperature, solvent and the volume of silylating reagent were investigated. Trimethylsilyl ether derivative of EZE was determined in selected ion monitoring (SIM, mass‐to‐charge ratio (m/z): 326) mode. The method was validated with respect to LOD and LOQ, precision, accuracy, linearity, specificity, stability, and recovery. The LOQ and LOD were found as 15 and 10 ng/mL, respectively. The linearity of the method ranged from 15 to 250 ng/mL. The correlation coefficient of the calibration curve was 0.9977 ± 0.0004 (± S.E.M.). The intra‐ and inter‐day precisions (RSD) were less than 6% and accuracies (bias) for intra‐ and inter‐day accuracy were found between –4.04 and 9.71% at four different concentration levels (15, 40, 100, 250 ng/mL). The proposed method was successfully applied to real human plasma samples for determination of total EZE. 相似文献
5.
P. R. Oliveira L. Brum Junior M. Fronza L. S. Bernardi S. M. K. Masiero S. L. Dalmora 《Chromatographia》2006,63(7-8):315-320
An analytical method based on liquid chromatography-tandem mass spectrometry (LC-MS-MS) was developed and validated for the
determination of ezetimibe in human plasma. Ezetimibe and etoricoxib (internal standard) were extracted from the plasma by
liquid-liquid extraction and separated on a C18 analytical column (50 × 3.0 mm I.D.) with acetonitrile:water (85:15, v/v) as mobile phase. Detection was carried out by positive electrospray ionization (ESI+) in multiple reaction monitoring (MRM)
mode. The chromatographic separation was obtained within 2.0 min and was linear in the concentration range of 0.25–20ng mL−1 for free ezetimibe and of 1–300ng mL−1 for total ezetimibe. The mean extraction recoveries for free and total ezetimibe from plasma were 96.14 and 64.11%, respectively.
Method validation investigated parameters such as linearity, precision, accuracy, specificity and stability, giving results
within the acceptable range. The proposed method was successfully applied to the quantitation of ezetimibe and its glucuronide
in human plasma to support clinical and pharmacokinetic studies. Moreover, the method was used for the quality control analysis
of pharmaceutical dosage forms.
Revised: 4 January and 3 February 2006 相似文献
6.
R. Patel D. Bhimani J. Patel D. Patel 《Journal of inclusion phenomena and macrocyclic chemistry》2008,60(3-4):241-251
The objectives of this research were to prepare and characterize inclusion complex of Ezetimibe (EZE) with cyclodextrins (β-cyclodextrin
(β-CD) and hydroxypropyl-β-cyclodextrin (HPβ-CD)) and to study the effect of complexation on the dissolution rate of EZE,
a water insoluble drug. Phase solubility curve was classified as A
P
-type for both cyclodextrins, indicating the 2:1 stoichiometric ratio for β-CD–EZE and HPβ-CD – EZE inclusion complexes. The
inclusion complexes in the molar ratio of 2:1 (β-CD–EZE and HPβ-CD–EZE) were prepared by various methods such as kneading,
coevaporation and physical mixing. The molecular behaviors of drug in all samples were characterized by fourier-transform
infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD) studies. The results
of these studies indicated that complex prepared by kneading and coevaporation methods showed inclusion of the EZE molecule
into the cyclodextrins cavities. The highest improvement in in-vitro dissolution profiles was observed in complex prepared
with hydroxypropyl-β-cyclodextrin using co-evaporation method. Mean dissolution time and similarity factor indicated significant
difference between the release profiles of EZE from complexes and physical mixtures and from pure EZE. 相似文献
7.
《Analytical letters》2012,45(9):1481-1490
A simple and sensitive electrochemical method is described for the determination of the cholesterol-reducing drug ezetimibe in aqueous solution. A glassy carbon electrode, modified with multiwalled carbon nanotubes and sodium dodecylsulphate was used as the working electrode. Ezetimibe yields a well-defined anodic peak at the surface of the electrode in an aqueous solution of pH 13. A linear amperometric calibration curve was obtained in the range of 1.2–78 μM (0.5–32.0 μg/mL) of ezetimibe, with a sensitivity of 88.6 nA/μM and a detection limit of 300 nM (0.12 μg/mL). The sensor was applied successfully to the determination of ezetimibe in pharmaceutical preparations. 相似文献
8.
HE Xing-lian XU Xian-xiu ZHENG Lian-you BAI Xu . Center for Combinatorial Chemistry Drug Discovery School of Pharmaceutical Sciences Jilin University Changchun P. R. China . College of Chemistry Changchun . College of Chemistry Northeast Normal University Changchun 《高等学校化学研究》2011,(2):232-236
A potential dual inhibitor(4) for exogenous absorption and endogenic synthesis of cholesterol was designed based on the conjugation of the β-lactam pharmacophore of ezetimibe and the δ-lactone pharmacophore of statins. The merger of ezetimibe and statin 4 was synthesized from p-hydroxybenzaldehyde through a ten-step route. 1H NMR analysis showed existence of four pairs of enantiomers(5.7:5.7:1:1, molar ratio). And compound 4 was found to lower total glucose(TG) level in rat serum via a high-cholesterol and ... 相似文献
9.
《Analytical letters》2012,45(7):1341-1357
Ezetimibe is the first of a new class of drugs that selectively inhibits cholesterol absorption in the small intestine and reduces plasma LDL cholesterol. In this study, electrochemical oxidation of ezetimibe was investigated on carbon based electrodes and a single and irreversible peak at both electrodes was observed. A linear response was detected between 2 × 10?6 and 8 × 10?5 M with glassy carbon electrode and between 2 × 10?6 and 2 × 10?4 M with a boron-doped diamond electrode in 0.1 M H2SO4 supporting electrolyte. The proposed methods were successfully applied for the determination of ezetimibe from pharmaceutical dosage forms and human serum samples. 相似文献
10.
<正>A convenient method for the synthesis of ezetimibe analogs as cholesterol absorption inhibitors was described.The key step in the synthesis was the intramolecular ring formation through Mitsunobu reaction.Furthermore,a new series of analogs was designed and synthesized. 相似文献