Publications by authors named "Su- Hwei Chen"

A simple cyclodextrin-mediated capillary zone electrophoresis method equipped with a laser-induced fluorescence detector was developed for chiral analysis of the excitatory amino acids aspartate (Asp) and glutamate (Glu). Plasma and cerebrospinal fluid (CSF) samples were pretreated with centrifugal filter devices before analysis to remove high-molecular-weight proteins (molecular weight cut-off: 3000) and then derivatized using 10 mM 6-carboxyfluorescein N-hydroxysuccinimide ester in DMSO under sonication at 25 °C for 2 h. After the derivatization reaction, reacted samples were diluted 100-fold with 5-([4,6-dichlorotriazin-2-yl]amino)fluorescein hydrochloride (DTAF) solution and then hydrodynamically subjected to capillary electrophoresis (0.

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We previously synthesized a chondroitin sulfate-graft-poly(ε-caprolactone) copolymer (H-CP) with a high content of poly(ε-caprolactone) (18.7 mol%), which self-assembled in water into a rod-like micelle to encapsulate hydrophobic camptothecin (CPT) in the core (micelle/CPT) for tumor-targeted drug delivery. As a result of the recognition of the micelle by CD44, the micelle/CPT entered CRL-5802 cells efficiently and released CPT efficaciously, resulting in higher tumor suppression than commercial CPT-11.

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Alzheimer's disease (AD) is a neurodegenerative disorder resulting from an impaired cholinergic function with loss of cognitive activity in the brain. Haptoglobin is a useful biomarker for AD analysis. Compared to the conventional enzyme-linked immunosorbent assay for haptoglobin analysis, the proposed immunoassay procedure reduces sample analysis time by approximately 55 min.

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In recent years, recreational use of Salvia divinorum (Lamiaceae), a herbal drug that contains a hallucinogenic ingredient, salvinorin A, has become a new phenomenon among young drug users. In Taiwan, as in many other countries, dry leaves of S. divinorum and its related concentrated extract products are available via the Internet.

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Chondroitin sulfate-g-poly(ε-caprolactone) (CP) copolymers were synthesized via atom transfer radical addition (ATRA). The CP copolymers self-assembled into micelles in water, and the micelles could be used to encapsulate a hydrophobic anticancer drug, camptothecin (CPT), in the core for tumor targeting delivery. The physicochemical properties of the micelles and CPT-loaded micelles were thoroughly characterized.

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Background: Donepezil has been approved, and higher dosages are recommended for the treatment of Alzheimer disease (AD). However, a few studies have reported different cognitive responses in patients with AD treated with donepezil without measuring the concentration.

Methods: We evaluated the relationships between the therapeutic responses and plasma concentrations of donepezil in various cognitive domains using the Cognitive Ability Screening Instrument among 37 patients with newly diagnosed mild stage AD taking donepezil 5 mg/d.

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A simple and sensitive capillary zone electrophoresis (CZE) with UV detection (214 nm) was developed and validated for the simultaneous determination of the acetylcholinesterase inhibitors (AChEI), donepezil, and rivastigmine, with antipsychotic drugs in plasma. A sample pretreatment by liquid-liquid extraction and subsequent quantification by CZE with field-amplified sample injection (FASI) was used. The optimum separation for these analytes was achieved in <20 min at 25 °C with a fused-silica capillary column of 60.

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The aim of this small pilot study was to evaluate the association between plasma concentrations of rivastigmine and its metabolite, NAP 226-90, and cognitive function in patients with Alzheimer's disease (AD). Rivastigmine-treated AD patients, who had been maintained on a fixed regimen of twice daily rivastigmine (6 to 12 mg/d) for ≥6 months, were eligible for evaluation. The assessments included cognitive assessment screening instrument (CASI) and clinical dementia rating scale, conducted at baseline and at 6-month follow-up.

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In this study, online sample concentration method, which coupled field-amplified sample injection (FASI) and sweeping technology with micellar electrokinetic chromatography (MEKC), was used to detect and analyze acidic and basic components in a single run. In order to concentrate the acidic and basic components simultaneously in a single run sweeping step, a combination of successive anion- and cation-selective injections were used. Before sample loading, a rinse buffer containing 50 mM Tris buffer (pH 3) with 41% MeOH and 0.

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The purpose of this study was to investigate the potential risk factors for the reactivation of the replication of hepatitis B virus (HBV) and hepatitis C virus (HCV) after transcatheter arterial chemoembolization (TACE) of hepatocellular carcinoma. Forty-four hepatocellular carcinoma patients treated by TACE using epirubicin plus mitomycin C were studied. Serum HBV DNA (n=17) and HCV RNA (n=27) levels were measured 1 day before and 3 months after TACE.

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This prospective study was to investigate the possible risk factors for the leakage of chemotherapeutic agent into the systemic circulation after transcatheter arterial chemoembolization (TACE) of hepatocellular carcinoma (HCC). Peripheral plasma concentrations of chemotherapeutic agents were determined at 1 hour and 72 hours after TACE by high-performance liquid chromatography in 53 patients. HCC were divided into three types namely single nodule (<5cm), multiple nodules (all <5cm), and main nodule measuring 5cm or more.

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It is demonstrated that nanoparticulate PEC with a crosslinked shell sustains DOX release and increases DOX activity against cancer cells. CSMA was synthesized to prepare PEC with chitosan. The double bonds among CSMA were used to form a shell crosslink.

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Donepezil has been approved for the treatment for mild-to-moderate Alzheimer's disease (AD), but the therapeutic response rate varies from 20 to 60%. A higher oral dosage was suggested to have a better therapeutic response in reported results, but the plasma concentration of donepezil was not examined with respect to the therapeutic outcomes in those studies. Therefore, we analyzed the therapeutic responses, measured by neuropsychological assessments, among 70 newly diagnosed AD patients taking donepezil (5 mg daily) in relation to their plasma concentration of donepezil, apolipoprotein E genotype, and demographic characteristics.

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A capillary column high-performance liquid chromatography (CapLC) method and a laser desorption ionization-time of flight (LDI-TOF)-MS method are described for the determination of quinapril, an angiotensin-converting enzyme inhibitor. Effective separation was achieved by using a C18 capillary column at a flow rate of 10 microL/min. For CapLC, quinapril and 7-hydroxycoumarin (internal standard) were detected at 210 and 320 nm, respectively.

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A sensitive high-performance CZE combining on-column field-amplified sample injection (FASI) has been developed for simultaneous determination of aripiprazole and its active metabolite, dehydroaripiprazole, in human plasma. A sample pretreatment by means of liquid-liquid extraction (LLE) (diethyl ether) with subsequent quantitation by FASI-CZE was used. The separation of aripiprazole and dehydroaripiprazole was performed using a BGE containing 150 mM phosphate buffer (pH 3.

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A nonionic surfactant MEKC method with LIF detection was developed for the simultaneous determination of memantine, an anti-Alzheimer's disease agent, and amantadine, an anti-Parkinson's disease drug, in human plasma. Before analysis, the plasma samples were pretreated by liquid-liquid extraction with ethyl acetate, and derivatized with 6-carboxyfluorescein N-hydroxysuccinimide ester. The chemical derivatization is performed with 6-carboxyfluorescein N-hydroxysuccinimide ester in ACN - 5 mM pH 9.

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Phenytoin is a widely used anti-seizure agent, and a good correlation is observed between its concentration in plasma and the clinical effect. We developed a selective CE with UV detection at 200 nm for analysis of free and total levels of phenytoin in human plasma based on MEKC. A sample pretreatment by liquid-liquid extraction with ethyl acetate for determination of total level of phenytoin and serum ultrafiltrate was prepared by ultrafiltration technique (ultrafiltration membrane 30 kDa; 2000 g, 10 min) for determination of free level of phenytoin and subsequent quantification by MEKC was used.

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A rapid and simple capillary zone electrophoresis (CZE) with ultraviolet detection has been developed for simultaneous determination of regular insulin and insulin aspart in bulk and commercial injection dosage forms. The simultaneous analysis of the tested drugs was performed in phosphate buffer (80 mM; pH 6.5).

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A new HPLC method has been developed and validated for the simultaneous determination of ticarcillin (TIC) and clavulanic acid (CA) in pharmaceutical formulations. The HPLC separation was achieved on a beta-cyclodextrin column (Cyclobond I, 250 x 4.6 mm, 5 microm) with methanol-16 mM pH 6.

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A simple and sensitive MEKC with UV detection was developed and validated for the simultaneous determination of acetylcholinesterase inhibitors including galantamine, rivastigmine and major metabolite NAP 226-90 in plasma. A sample pretreatment by liquid-liquid extraction with diethylether and subsequent quantification by MEKC was used. The optimum separation for these analytes was achieved in <10 min at 25 degrees C with a fused-silica capillary column of 30.

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We developed a simple and selective CE with UV detection at 233 nm for the analysis of metformin in plasma based on direct sample injection without any pretreatment. The sample was employed with an electrokinetic injection of 10 kV for 100 s. CE separation of metformin from biological matrix was performed at 25 degrees C using a BGE consisting of 25 mM Tris buffer at pH 4.

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Field-amplified sample stacking (FASS) in capillary electrophoresis (CE) was used to determine the concentration of donepezil, an acetylcholinesterase inhibitor, in human plasma. A sample pretreatment by liquid-liquid extraction with isopropanol/n-hexane (v/v 3:97) and subsequent quantification by FASS-CE was used. Before sample loading, a water plug (0.

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A sulfated beta-cyclodextrin (sulfated beta-CD)-mediated capillary electrophoresis method is described for the enantioseparation of cetirizine using achiral cefazolin as an internal standard. The enantioseparation of the drug was performed in a borate buffer (5 mM, pH 8.7) with 1% sulfated beta-CD (w/v) as chiral selector at 10 kV.

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An accurate and reproducible method for the simultaneous determination of ampicillin (AMP), sulbactam (SUL), and cefoperazone (CFP) in pharmaceutical formulations by using HPLC with beta-CD stationary phase was developed. It involved the use of the added tetraethylammonium acetate (TEAA) reagent, pH, and methanol as the significant parameters to find the optimum separation condition. A high resolution and selectivity of analytes was obtained by running the mobile phase in methanol-5 mM TEAA buffer = 35:65 (v/v, pH 4.

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