Optimization Of A Gas Chromatography-Mass Spectrometry Method Using Chemometric Techniques For The Determination Of Ezetimibe In Human Plasma

A new, rapid, and sensitive gas chromatography-mass spectrometry (GC-MS) method was developed for the determination of ezetimibe (EZE) in human plasma. EZE was derivatized prior to GC-MS analysis. Various derivatization techniques such as acetylation, methylation, and silylation were tried. EZE was extracted from plasma with high recovery (94.39%-97.57%) using methyl tertbutyl ether and carbonate buffer (pH 9). Chromatographic conditions were optimized using chemometric methods. In the first step, optimization with factorial design, chromatographic variables (initial and final column temperature, oven ramp rate, and flow rate of gas) were screened to select important variables for the retention of EZE. In the second step, central composite design was applied to decide on the retention time of EZE. The analysis was achieved in a short period of time (<4 min). The developed method was validated for parameters including specificity, limit of quantitation, linearity, accuracy, precision, recovery, stability, robustness, and ruggedness. The limit of quantitation was found to be 10 ng mL(-1). The method was successfully applied to determine total EZE in the plasma of hypercholesterolemic patients.WoSScopu

Hplc Fingerprinting Of Sennosides In Laxative Drugs With Isolation Of Standard Substances From Some Senna Leaves

Senna leaves are one of the oldest medicinal herbs and they are used as laxative. Herbal teas which contain senna leaves are most commonly used to promote weight loss. The quality control of slimming teas which contain Senna leaves and also pharmaceutical preparations including Senna extract enriched by sennoside B was achieved by HPLC fingerprinting method. While the presence of sennoside A and B in laxative drugs was proved, it was seen to be devoid of sennosides in slimming teas. Kaempferol 3-O-beta-D-gentiobioside ( 1), aloe-emodine 8-O-beta-D-glucopyranoside ( 2), rhein 8-O-beta-D-glucopyranoside ( 3), torachrysone 8-O-beta-D-glucopyranoside ( 4), isorhamnetine 3-O-beta-D-gentiobioside ( 5) were also isolated from Senna leaves.Wo

Adulteration Determining Of Pharmaceutical Forms Of Ginkgo Biloba Extracts From Different International Manufacturers

In this study, Ginkgo biloba products used for the same purpose, but licensed to varying authorities were analyzed in point of similarity to each other. A group of these products were licensed from health authorities as herbal medicinal product (HMP), while the other groups of products were licensed as the food supplement (FS). The evaluation of their phytoequivalence was carried out comparing the chromatographic fingerprint profiles. Furthermore, ginkgolides (ginkgolides GA, GB, GC, and GJ) and flavonoid aglycones (quercetin, kaempferol, and isorhamnetin) were quantitatively analyzed by using liquid chromatography-mass spectrometry (LC-MS) and HPLC-diode Array detector (HPLC-DAD) assays. All six herbal medicinal products and two food supplements were found to be phytoequivalent to each other, but five of the seven food supplements did not possess similar content as herbal medicinal products, and the quantity of ginkgolides and flavonoid aglycones per tablet/capsule was found to be lower than declared on the labels. In addition, food supplements were found to be adultered with rutin to reach expected total flavonoid glycosides amount.Wo

Ultrasensitive Detection And Quantification Of Acidic Disaccharides Using Capillary Electrophoresis And Quantum Dot-Based Fluorescence Resonance Energy Transfer

Rapid and highly sensitive detection of the carbohydrate components of glycoconjugates is critical for advancing glycobiology. Fluorescence (or Forster) resonance energy transfer (FRET) is commonly used in detection of DNA, in protein structural biology, and in protease assays but is less frequently applied to glycan analysis due to difficulties in inserting two fluorescent tags into small glycan structures. We report an ultrasensitive method for the detection and quantification of a chondroitin sulfate disaccharide based on FRET, involving a CdSe-ZnS core-shell nanocrystal quantum dot (QD) streptavidin conjugate donor and a Cy5 acceptor. The disaccharide was doubly labeled with biotin and Cy5. QDs then served to concentrate the target disaccharide, enhancing the overall energy transfer efficiency, with unlinked QDs and Cy5 hydrazide producing nearly zero background signal in capillary electrophoresis using laser-induced fluorescence detection with two different band-pass filters. This method is generally applicable to the ultrasensitive analysis of acidic glycans and offers promise for the high-throughput disaccharide analysis of glycosaminoglycans.Wo

Capillary Electrophoresis For Total Glycosaminoglycan Analysis

A capillary zone electrophoresis-laser-induced fluorescence detection (CZE-LIF) method was developed for the simultaneous analysis of disaccharides derived from heparan sulfate, chondroitin sulfate/dermatan sulfate, hyaluronan, and keratan sulfate. Glycosaminoglycans (GAGs) were first depolymerized with the mixture of GAG lyases (heparinase I, II, III and chondroitinase ABC and chondroitinase AC II) and GAG endohydrolase (keratinase II) and the resulting disaccharides were derivatized by reductive amination with 2-aminoacridone. Nineteen fluorescently labeled disaccharides were separated using 50 mM phosphate buffer (pH 3.3) under reversed polarity at 25 kV. Using these conditions, all the disaccharides examined were baseline separated in less then 25 min. This CZE-LIF method gave good reproducibility for both migration time (a parts per thousand currency sign1.03 % for intraday and a parts per thousand currency sign4.4 % for interday) and the peak area values (a parts per thousand currency sign5.6 % for intra- and a parts per thousand currency sign8.69 % for interday). This CZE-LIF method was used for profiling and quantification of GAG derivative disaccharides in bovine cornea. The results show that the current CZE-LIF method offers fast, simple, sensitive, reproducible determination of disaccharides derived from total GAGs in a single run.Wo