Determination of Bevantolol in Human Plasma by High Performance Liquid Chromatography Using Solid Phase Extraction Technique

Tran Quoc Trung,Pham Hai Long,Ahmed M Al-Abd,Hyo Jeong Kuh,Ho Yoon Lee,황성주,김경호 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.7

A method was developed and fully validated for the determination of bevantolol, an adrenergicreceptor blocker, in human plasma. Bevantolol and betaxolol as internal standard (I.S) were extracted from 1mL of human plasma by solid phase extraction technique using Sep-pak silica cartridge. Chromatographic separation was accomplished under isocratic conditions using a reverse-phase C8 analytical column and mixture of dibasic ammonium phosphate (pH 5.7; 50mM)-acetonitrile (75:25, v/v) as mobile phase, with a detection wavelength at 220 nm. The method was proved to be specific by testing six different human plasma sources. Linearity was established for the concentration ranges of 40-1600 ng/mL with correlation coefficent of 0.9995. The lower limit of quantification 40 ng/mL with precision of 10.9% as C.V%.

Determination of Bevantolol in Human Plasma by High Performance Liquid Chromatography Using Solid Phase Extraction Technique

Trung, Tran-Quoc,Long, Pham-Hai,Al-Abd, Ahmed M,Ku, Hyo-Jeong,Lee, Ho-Yoon,Hwang, Sung-Joo,Kim, Kyeong-Ho 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.7

A method was developed and fully validated for the determination of bevantolol, an adrenergic-receptor blocker, in human plasma. Bevantolol and betaxolol as internal standard (I.S) were extracted from 1mL of human plasma by solid phase extraction technique using Sep-pak silica cartridge. Chromatographic separation was accomplished under isocratic conditions using a reverse-phase $C_8$ analytical column and mixture of dibasic ammonium phosphate (pH 5.7; 50mM)-acetonitrile (75:25, v/v) as mobile phase, with a defection wavelength at 220 nm. The method was proved to be specific by testing six different human plasma sources. Linearity was established for the concentration ranges of 40-1600 ng/mL with correlation coefficent of 0.9995. The lower limit of quantification 40 ng/mL with precision of 10.9% as C.V%.

Preparative Method of R-(?)-Ibuprofen by Diastereomer Crystallization

Tran Quoc Trung,Jong Moon Kim,김경호 대한약학회 2006 Archives of Pharmacal Research Vol.29 No.1

The economic and effective method for preparation of R-(-)-ibuprofen by diastereomer crystallization was developed. R-(-)-ibuprofen was resolved from racemic ibuprofen by forming R-(-)- ibuprofen-R-(+)-α-methylbenzylamine diastereomeric salt with R-(+)-α-methylbenzylamine and crystallization. The purity of R-(-)-ibuprofen-R-(+)-α-methylbenzylamine diastereomeric salt was tested and confirmed using HPLC and 1H-NMR method. The pure diastereomeric salt collected from repeated recrystallization was further fractionated by liquid-liquid extraction to the pure enantiomer without racemization. R-(-)-ibuprofen was recovered producing overall yield of 2.4% with the purity more than 99.97%.

Chiral Separation of Fluvastatin Enantiomers by Capillary Electrophoresis

Trung, Tran Quoc,Dung, Phan Thanh,Hoan, Nguyen Ngoc,Kim, Dae-Joong,Lee, Joo-Huyn,Kim, Kyeong-Ho 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.8

An analytical CE method was developed for the enantiomeric purity determination of fluvastatin enantiomers. Fluvastatin enantiomers were separated on an uncoated fused silica with 100 mM-borate solution containing 30 mg/mL of (2-hydroxypropyl)-$\beta$-cyclodextrin (HP-$\beta$-CD) as running buffer and fenoprofen as an internal standard. The linearity was observed within a $400-700\;{\mu}g/mL$ concentration range ($r^2{\geq}0.995$) for both fluvastatin enantiomers. The repeatability expressed as coefficient of variation (CV) of the method were 0.96 and 0.92% for (+)-3R, 5S and (-)-3S, 5R-fluvastatin, respectively. The limit of detection and quantification for both fluvastatin enantiomers were $1.5\;{\mu}g/mL$ and $2.5\;{\mu}g/mL$, respectively.

Finite element analysis for functionally graded porous nano-plates resting on elastic foundation

Quoc-Hoa Pham,Phu-Cuong Nguyen,Van-Ke Tran,Trung Nguyen-Thoi 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.41 No.2

This paper proposes an improved triangular element based on the strain approach and the Reissner-Mindlin theory to investigate the static, free vibration, and buckling response of functionally graded porous (FGP) nano-plates resting on the Parternak’s two-parameter elastic medium foundation. The internal pores of nano-plates are described by two distribution laws, including uneven porosity distribution and logarithmic-uneven porosity distribution. Using Hamilton’s principle, equilibrium equations of FGP nano-plates lying on a two-parameter foundation are obtained. The most remarkable feature of the improved triangular element is the degrees of freedom of elements approximated by Lagrange functions for the membrane strain and by the high-degree polynomial functions for the bending strain. The numerical results of the present work are compared with the available results in the literature to evaluate the performance of the proposed approach. Effects of geometrical and material properties such as the power-law index n, the porosity coefficient ξ, the nonlocal coefficient μ, and the parameters of the elastic foundation on the static, free vibration, and buckling behavior of the FGP nano-plates are examined in detail.

One Rank Cuckoo Search Algorithm for Bi-Objective Load Dispatch Problem

Cuong Dinh Tran,Thang Trung Nguyen,Hanh Minh Hoang,Bao Quoc Nguyen 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.4

This paper presents the application of a One Rank Cuckoo Search Algorithm (ORCSA) to bi-objective load dispatch (BOLD) problem where two objectives including fuel and emission are taken into consideration. ORCSA is an improvement of basic Cuckoo search algorithm (BCSA) where several modifications are carried out so as to improve the performance of the BCSA. The performance of the proposed ORCSA is validated by using two systems including a three-unit system with one load case and a six-unit system with three load cases and comparing the obtained results with other methods available in the article. The analysis on the result comparison indicates that the ORCSA is very efficient for the problem.

Chiral Purity Test of Bevantolol by Capillaryelectrophoresis and High Performance Liquid Chromatography

Long, Pham Hai,Trung, Tran Quoc,Oh, Joung-Won,Kim, Kyeong-Ho The Pharmaceutical Society of Korea 2006 Archives of Pharmacal Research Vol.29 No.9

Two methods for the chiral purity determination of bevantolol were developed, namely capillary electrophoresis (CE) using carboxymethyl-${\beta}$-cyclodextrin (CM-${\beta}$-CD) as a chiral selector and high-perfomance liquid chromatography (HPLC) using a chiral stationary phase. In the HPLC method, the separation of bevantolol enantiomers was performed on a Chiralpak AD-H column by isocratic elution with n-hexane-ethanol-diethylamine (10:90:0.1, v/v/v) as mobile phase. In the CE method, bevantolol enantiomers were separated on an uncoated fused silica capillary with 50 mM amonium phosphate dibasic adjusted to a pH 6.5 with phosphoric acid containing 15 mM CM-${\beta}$-CD as running buffer. Validation data such as linearity, recovery, detection limit, and precision of the two methods are presented. The detection limits of S-(-)-bevantolol were 0.1% and 0.05% for CE and HPLC method, respectively and R-(+)-bevantolol were 0.15% and 0.05% for CE and HPLC method, respectively. There was generally good agreement between the HPLC and CE results.

Preparative Resolution of Etodolac Enantiomers by Preferential Crystallization Method

Phan Thanh Dung,Tran Quoc Trung,Kyeong Ho Kim 대한약학회 2009 Archives of Pharmacal Research Vol.32 No.10

Pure enantiomers are of large interest for several industries. This study was aimed to establish a method for separation of etodolac enantiomers by preferential crystallization after a conglomerate formation of its derivatives. S-(+)-etodolac and R-(-)-etodolac enantiomers were both prepared by classical resolution via crystallization of diastereoisomeric salt with (-)-brucine and (-)-cinchonidine. Enantiomeric purity of etodolac was determined by HPLC method using Chiralcel OD-H column. The pure diastereomeric salt collected from repeated recrystallization was further fractionated by liquid-liquid extraction to pure enantiomers. Etodolac enantiomers were recovered with overall yield more than 20% and the purities were over 99.9%.

Chiral Purity Test of Bevantolol by Capillaryelectrophoresis and High Performance Liquid Chromatography

Pham Hai Long,Tran Quoc Trung,Joung Won Oh,김경호 대한약학회 2006 Archives of Pharmacal Research Vol.29 No.9

Two methods for the chiral purity determination of bevantolol were developed, namely capillary electrophoresis (CE) using carboxymethyl-β-cyclodextrin (CM-β-CD) as a chiral selector and high-perfomance liquid chromatography (HPLC) using a chiral stationary phase. In the HPLC method, the separation of bevantolol enantiomers was performed on a Chiralpak AD-H column by isocratic elution with n-hexane-ethanol-diethylamine (10:90:0.1, v/v/v) as mobile phase. In the CE method, bevantolol enantiomers were separated on an uncoated fused silica capillary with 50 mM amonium phosphate dibasic adjusted to a pH 6.5 with phosphoric acid containing 15 mM CM-β-CD as running buffer. Validation data such as linearity, recovery, detection limit, and precision of the two methods are presented. The detection limits of S-(-)- bevantolol were 0.1% and 0.05% for CE and HPLC method, respectively and R-(+)-bevantolol were 0.15% and 0.05% for CE and HPLC method, respectively. There was generally good agreement between the HPLC and CE results.

Atypical Toxocara canis-Induced Hepatic Visceral Larva Migrans: Diagnostic Challenges and Literature Review

Tien Manh Huynh,Khanh Quoc Le Tran,Trung Hoang Dinh,Man Minh Vo,Thong Quang Pham,Thong Duy Vo 대한소화기학회 2024 대한소화기학회지 Vol.83 No.6

Toxocariasis, a zoonotic infection transmitted by Toxocara canis (from dogs) and Toxocara cati (from cats) larvae, poses rare but severe risks to humans. We present a case of hepatic visceral larva migrans (VLM) caused by Toxocara canis in a 21-year-old male with a history of close contact with a pet dog. Initial symptoms and imaging findings mimicked a pyogenic liver abscess. The initial laboratory investigations revealed neutrophilia and elevated levels of IgE. Despite broad-spectrum antibiotics, persistent fever prompted further investigation. Subsequent serological testing for Toxocara antibodies and histopathological analysis of liver tissue demonstrating eosinophil infiltrates and Charcot-Leyden crystals led to a confirmed diagnosis of a liver abscess caused by Toxocara canis. Serological testing for Toxocara antibodies and histopathological analysis of liver tissue confirmed a Toxocara canis-induced liver abscess. Albendazole treatment yielded significant clinical improvement. This case highlights the necessity of considering toxocariasis in liver abscess differentials, particularly in high-seroprevalence regions like Vietnam. Relying solely on serological tests may be insufficient, emphasizing the need for corroborative evidence, including invasive procedures like liver biopsy, for accurate hepatic toxocariasis diagnosis.