The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform
Youwen Tang - One of the best experts on this subject based on the ideXlab platform.
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evaluation of a novel silica supported sol gel sorbent prepared by a surface molecular imprinting technique for the selective separation of Estazolam from human plasma
Mikrochimica Acta, 2009Co-Authors: Guoyou Jin, Youwen TangAbstract:A molecular imprinting polymer (MIP) based on surface modification of silica gel was prepared via the sol–gel process with 3-aminopropyltriethoxysilane and phenyltrimethoxysilane as functional monomers, and Estazolam as the template. The imprinted silica sorbent was characterized by Fourier Transform Infrared Spectroscopy, surface elemental analysis, and scanning electron microscopy (SEM). An MIP of agglomerated nano-particles with multi-pores was grafted onto the surface of the silica gel after hydrolytic condensation of the siloxane. The imprinted silica sorbent was used for solid phase extraction (SPE). Using water as loading solvent, the extraction efficiency for Estazolam was higher compared to the use of an organic solvent. The imprinted silica sorbent was selective not only for the template, but also for the analogue. Compared to C18-SPE and liquid–liquid extraction, the MIP-SPE was the most feasible technique for extraction of Estazolam from human plasma; up to 98.7 ± 1.2% recovery was achieved.
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Evaluation of a novel silica-supported sol–gel sorbent prepared by a surface molecular imprinting technique for the selective separation of Estazolam from human plasma
Mikrochimica Acta, 2008Co-Authors: Guoyou Jin, Youwen TangAbstract:A molecular imprinting polymer (MIP) based on surface modification of silica gel was prepared via the sol–gel process with 3-aminopropyltriethoxysilane and phenyltrimethoxysilane as functional monomers, and Estazolam as the template. The imprinted silica sorbent was characterized by Fourier Transform Infrared Spectroscopy, surface elemental analysis, and scanning electron microscopy (SEM). An MIP of agglomerated nano-particles with multi-pores was grafted onto the surface of the silica gel after hydrolytic condensation of the siloxane. The imprinted silica sorbent was used for solid phase extraction (SPE). Using water as loading solvent, the extraction efficiency for Estazolam was higher compared to the use of an organic solvent. The imprinted silica sorbent was selective not only for the template, but also for the analogue. Compared to C18-SPE and liquid–liquid extraction, the MIP-SPE was the most feasible technique for extraction of Estazolam from human plasma; up to 98.7 ± 1.2% recovery was achieved.
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Preparation and Application of a Novel Silica-Supported Organic-Inorganic Hybrid Molecular Imprinting Polymer
Analytical Letters, 2008Co-Authors: Guoyou Jin, Youwen Tang, Shizhu Liu, Songcai Wang, Ruokui XingAbstract:Abstract A novel Estazolam-imprinted silica sorbent was prepared by the surface imprinting technique using 3-aminopropyltriethoxysilane (APTEOS) and phenyltrimethoxysilane (PTMOS) as functional monomers. The functional monomers are expected to form hydrogen bonds and π-π interactions with Estazolam. The imprinted silica sorbent was characterized by Fourier transform infrared spectroscopy (FT-IR), element analysis, and scanning electron micrograph (SEM). Compared to C18 solid phase extraction (SPE) and liquid-liquid extraction, molecular imprinting polymer (MIP) SPE was the most feasible method to extract Estazolam from human plasma, and the recovery of Estazolam was up to 98.7±1.2%.
Guoyou Jin - One of the best experts on this subject based on the ideXlab platform.
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evaluation of a novel silica supported sol gel sorbent prepared by a surface molecular imprinting technique for the selective separation of Estazolam from human plasma
Mikrochimica Acta, 2009Co-Authors: Guoyou Jin, Youwen TangAbstract:A molecular imprinting polymer (MIP) based on surface modification of silica gel was prepared via the sol–gel process with 3-aminopropyltriethoxysilane and phenyltrimethoxysilane as functional monomers, and Estazolam as the template. The imprinted silica sorbent was characterized by Fourier Transform Infrared Spectroscopy, surface elemental analysis, and scanning electron microscopy (SEM). An MIP of agglomerated nano-particles with multi-pores was grafted onto the surface of the silica gel after hydrolytic condensation of the siloxane. The imprinted silica sorbent was used for solid phase extraction (SPE). Using water as loading solvent, the extraction efficiency for Estazolam was higher compared to the use of an organic solvent. The imprinted silica sorbent was selective not only for the template, but also for the analogue. Compared to C18-SPE and liquid–liquid extraction, the MIP-SPE was the most feasible technique for extraction of Estazolam from human plasma; up to 98.7 ± 1.2% recovery was achieved.
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Evaluation of a novel silica-supported sol–gel sorbent prepared by a surface molecular imprinting technique for the selective separation of Estazolam from human plasma
Mikrochimica Acta, 2008Co-Authors: Guoyou Jin, Youwen TangAbstract:A molecular imprinting polymer (MIP) based on surface modification of silica gel was prepared via the sol–gel process with 3-aminopropyltriethoxysilane and phenyltrimethoxysilane as functional monomers, and Estazolam as the template. The imprinted silica sorbent was characterized by Fourier Transform Infrared Spectroscopy, surface elemental analysis, and scanning electron microscopy (SEM). An MIP of agglomerated nano-particles with multi-pores was grafted onto the surface of the silica gel after hydrolytic condensation of the siloxane. The imprinted silica sorbent was used for solid phase extraction (SPE). Using water as loading solvent, the extraction efficiency for Estazolam was higher compared to the use of an organic solvent. The imprinted silica sorbent was selective not only for the template, but also for the analogue. Compared to C18-SPE and liquid–liquid extraction, the MIP-SPE was the most feasible technique for extraction of Estazolam from human plasma; up to 98.7 ± 1.2% recovery was achieved.
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Preparation and Application of a Novel Silica-Supported Organic-Inorganic Hybrid Molecular Imprinting Polymer
Analytical Letters, 2008Co-Authors: Guoyou Jin, Youwen Tang, Shizhu Liu, Songcai Wang, Ruokui XingAbstract:Abstract A novel Estazolam-imprinted silica sorbent was prepared by the surface imprinting technique using 3-aminopropyltriethoxysilane (APTEOS) and phenyltrimethoxysilane (PTMOS) as functional monomers. The functional monomers are expected to form hydrogen bonds and π-π interactions with Estazolam. The imprinted silica sorbent was characterized by Fourier transform infrared spectroscopy (FT-IR), element analysis, and scanning electron micrograph (SEM). Compared to C18 solid phase extraction (SPE) and liquid-liquid extraction, molecular imprinting polymer (MIP) SPE was the most feasible method to extract Estazolam from human plasma, and the recovery of Estazolam was up to 98.7±1.2%.
Tian Lan - One of the best experts on this subject based on the ideXlab platform.
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Determination of forbidden addition drugs of Diazepam,Clonazepam and Estazolam in tranquilizing mind traditional Chinese medicine by UPLC-MS/MS
The Journal of Pharmaceutical Practice, 2011Co-Authors: Tian LanAbstract:Objective To establish a specific method for determination of forbidden addition drugs of Diazepam,Clonazepan and Estazolam in tranquilizing mind Traditional Chinese Medicine.Methods Diazepam,Clonazepam and Estazolam were determined and analyzed by UPLC-MS/MS.ACQUITY BEH C_(18) analysis column(2.1 mm×50 mm,1.7μm) was used with the mobile phase of 10 mmol/L ammonium acetate and acetonitrile(90:10) with gradient elution.The flow rate was 0.4 ml/min,and the detection wavelength was 254 nm.EIS ion source was used with positive ion monitoring.Results The standard curves of Diazepam,Clonazepam and Estazolam showed good linearity over the concentration rang of 109.8～878.4,102.1～816.8,106.9～855.2 ng/ml,The detection limits were 0.06,2.5×10~(-3),2.8×10~(-3) ng, the quantitation limits were 0.19,8.2×10~(-3),9.2×10~(-3) ng,the average recoveries of three chemicals was 95.7%～103.7%.Conclution The method was specific,sensitive,easily and quickly,which could be used to detect Diazepam,Clonazepan and Estazolam in tranquilizing mind traditional Chinese medicine.
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determination of forbidden addition drugs of diazepam clonazepam and Estazolam in tranquilizing mind traditional chinese medicine by uplc ms ms
The Journal of Pharmaceutical Practice, 2011Co-Authors: Tian LanAbstract:Objective To establish a specific method for determination of forbidden addition drugs of Diazepam,Clonazepan and Estazolam in tranquilizing mind Traditional Chinese Medicine.Methods Diazepam,Clonazepam and Estazolam were determined and analyzed by UPLC-MS/MS.ACQUITY BEH C_(18) analysis column(2.1 mm×50 mm,1.7μm) was used with the mobile phase of 10 mmol/L ammonium acetate and acetonitrile(90:10) with gradient elution.The flow rate was 0.4 ml/min,and the detection wavelength was 254 nm.EIS ion source was used with positive ion monitoring.Results The standard curves of Diazepam,Clonazepam and Estazolam showed good linearity over the concentration rang of 109.8～878.4,102.1～816.8,106.9～855.2 ng/ml,The detection limits were 0.06,2.5×10~(-3),2.8×10~(-3) ng, the quantitation limits were 0.19,8.2×10~(-3),9.2×10~(-3) ng,the average recoveries of three chemicals was 95.7%～103.7%.Conclution The method was specific,sensitive,easily and quickly,which could be used to detect Diazepam,Clonazepan and Estazolam in tranquilizing mind traditional Chinese medicine.
Jie-hua Shi - One of the best experts on this subject based on the ideXlab platform.
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Investigation of the binding interaction between Estazolam and bovine serum albumin: multi-spectroscopic methods and molecular docking technique.
Journal of biomolecular structure & dynamics, 2016Co-Authors: Yin-fei Zhang, Kai-li Zhou, Yan-yue Lou, Dong-qi Pan, Jie-hua ShiAbstract:Estazolam (Figure S1(a)), is one of the representative of the triazolobenzodiazepine drugs that acts on the central nervous system, mainly prescribed as a sedative and hypnotic agent (Lee et al., 2...
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Investigation of the binding interaction between Estazolam and bovine serum albumin: multi-spectroscopic methods and molecular docking technique
2016Co-Authors: Yin-fei Zhang, Kai-li Zhou, Yan-yue Lou, Dong-qi Pan, Jie-hua ShiAbstract:Investigation of the binding interaction between Estazolam and bovine serum albumin: multi-spectroscopic methods and molecular docking techniqu
Koichi Otani - One of the best experts on this subject based on the ideXlab platform.
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Identification of human cytochrome P450 enzymes involved in the formation of 4-hydroxyEstazolam from Estazolam
Xenobiotica; the fate of foreign compounds in biological systems, 2005Co-Authors: Masatomo Miura, Koichi Otani, Tadashi OhkuboAbstract:To predict drug interactions with Estazolam, the biotransformation of Estazolam to its major hydoxylated metabolite, 4-hydroxyEstazolam was studied in vitro using pooled human liver microsomes and individual expressed human cytochrome P450 (CYP) enzymes. Estazolam was metabolized to 4-hydroxyEstazolam according to the Hill kinetic model in pooled human liver microsomes. The Km value for the 4-hydroxylation of Estazolam was 24.1 µM, and the Vmax value was 52.6 pmol min−1 mg−1 protein. The formation of 4-hydroxyEstazolam from Estazolam in pooled human liver microsomes was significantly inhibited by itraconazole and erythromycin, specific CYP3A4 inhibitors, in a dose-dependent manner, with IC50 values of 1.1 and 12.8 µM, respectively. When Estazolam was incubated with expressed human CYP enzymes (CYP1A2, CYP2A6, CYP2C9, CYP2C19, CYP2D6, CYP2E1 and CYP3A4), it was metabolized only by CYP3A4. In conclusion, the biotransformation of Estazolam to 4-hydroxyEstazolam was catalyzed by CYP3A4.
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Effects of the CYP2C19 genotype and cigarette smoking on the single oral dose pharmacokinetics and pharmacodynamics of Estazolam.
Progress in neuro-psychopharmacology & biological psychiatry, 2003Co-Authors: Toshiaki Aoshima, Masatomo Miura, Tadashi Ohkubo, Kazunobu Sugawara, Naoyuki Okuyama, Takashi Fukasawa, Yohei Otsuji, Gisa Gerstenberg, Koichi OtaniAbstract:The effects of the cytochrome P450 (CYP)2C19 genotype and cigarette smoking on the single oral dose pharmacokinetics and pharmacodynamics of Estazolam were studied in 16 healthy male volunteers. The two mutated alleles (CYP2C19*2 and CYP2C19*3) causing absent CYP2C19 activity were identified by PCR-based restriction enzyme analysis. Five subjects had no mutated allele, five had one mutated allele, and six had two mutated alleles. Seven subjects were smokers, and nine were nonsmokers. The subjects received a single oral 4-mg dose of Estazolam, and blood samplings and evaluation of psychomotor function were conducted up to 72 h after dosing. There was no significant difference among the groups with no, one, and two mutated alleles for the peak plasma concentration (145.2+/-36.5 vs. 142.1+/-33.6 vs. 113.2+/-29.7 ng/ml), area under the plasma concentration-time curve (0- infinity ) (4916.0+/-1276.4 vs. 4389.6+/-736.1 vs. 4047.3+/-613.8 ng x h/ml), apparent oral clearance (0.22+/-0.05 vs. 0.25+/-0.03 vs. 0.25+/-0.03 ml/min/kg), and elimination half-life (24.4+/-4.6 vs. 29.6+/-8.5 vs. 30.7+/-3.9 h). Similarly, none of the pharmacokinetic parameters was significantly different between the nonsmoker and smoker groups. Neither the number of mutated allele nor cigarette smoking affected the psychomotor function parameters significantly. The present study suggests that neither the CYP2C19 genotype nor cigarette smoking affects the single oral dose pharmacokinetics and pharmacodynamics of Estazolam.
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Determination of Estazolam in plasma by high-performance liquid chromatography with solid-phase extraction.
Analytical sciences : the international journal of the Japan Society for Analytical Chemistry, 2002Co-Authors: Masatomo Miura, Tadashi Ohkubo, Kazunobu Sugawara, Naoyuki Okuyama, Koichi OtaniAbstract:A high-performance liquid chromatography (HPLC) assay was developed for the determination of Estazolam in human plasma. Estazolam and alprazolam as an internal standard were detected by ultraviolet absorbance at 240 nm. Estazolam in plasma was extracted by a rapid and simple procedure based on cyanopropyl bonded-phase extraction. Chromatographic separation was achieved with a reversed-phase C8-5 column using a mobile phase of 0.5% potassium dihydrogenphosphate(pH 4.5)-acetonitrile (70:30, v/v). The determination of Estazolam was possible in the concentration range of 1.0 - 200.0 ng/mL. The mean recovery of Estazolam added to plasma was 96.1 ± 1.5% with coefficients of variation of less than 5.5%. This method is applicable for accurately monitoring the plasma level of Estazolam in healthy subjects participating in scientific research.