A5083814221- Analytical Chemistry and Chromatography
- Mass Spectrometry Techniques and Applications
- Pesticide Residue Analysis and Safety
- Analytical chemistry methods development
- Analytical Methods in Pharmaceuticals
- Pharmacogenetics and Drug Metabolism
- Carcinogens and Genotoxicity Assessment
- Peptidase Inhibition and Analysis
- Microfluidic and Capillary Electrophoresis Applications
- Metabolomics and Mass Spectrometry Studies
- Diabetes Treatment and Management
- Advanced Chemical Physics Studies
- Computational Drug Discovery Methods
- Neuropeptides and Animal Physiology
- Protein purification and stability
- Chemical Synthesis and Analysis
- Intravenous Infusion Technology and Safety
- Vibration Control and Rheological Fluids
- Quinazolinone synthesis and applications
- Network Traffic and Congestion Control
- Chemical Reactions and Isotopes
- Electrostatic Discharge in Electronics
- Electrochemical sensors and biosensors
- Advanced Malware Detection Techniques
- Phenothiazines and Benzothiazines Synthesis and Activities
Purdue University West Lafayette
2025
Vertex Pharmaceuticals (United States)
2022
Purdue University Fort Wayne
2020
GlaxoSmithKline (United States)
2007-2016
GlaxoSmithKline (United Kingdom)
2004-2012
Indiana University – Purdue University Fort Wayne
2008-2009
Merck & Co., Inc., Rahway, NJ, USA (United States)
2001-2007
Abstract A new type of quadrupole linear ion trap mass spectrometer, Q TRAP™ LC/MS/MS system (Q TRAP™), was evaluated for its performance in two studies: firstly, the vitro metabolism gemfibrozil human liver microsomes, and, secondly, quantification propranolol rat plasma. With built‐in information‐dependent‐acquisition (IDA) software, instrument utilizes full scan MS mode and/or constant neutral loss scans as survey to trigger product (MS 2 ) and 3 experiments obtain structural information...
Abstract An Erratum for this article has been published in Rapid Communications Mass Spectrometry 17(3) 2003, 264 Biotransformation studies performed on an investigational compound (I, represented by R1‐CH(NH 2 )‐CO‐N(R2)‐CH ‐S‐R3) led to the identification of five metabolites (M1–M5). Based LC/MS (liquid chromatography/mass spectrometry) analysis which included use H O and D mobile phases, they were identified as sulfoxide (M1), sulfone (M2), carbamoyl glucuronide (M3), N‐glucuronide (M4),...
Arylsulfonamides are attractive pharmacophores for drug candidates. Fragmentation behaviors of selected aromatic sulfonamides were investigated using electrospray ionization mass spectrometry in the positive ion mode. Some afforded unique loss 64 (loss SO(2)) ions upon collision-induced dissociation followed by intramolecular rearrangements gas phase. This SO(2) elimination-rearrangement pathway leading to generation [M + H - SO(2)](+) appeared be susceptible substitutions on (Ar) ring that...
The pharmacokinetics, metabolism, and excretion of sitagliptin [MK-0431; (2<i>R</i>)-4-oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-<i>a</i>]pyrazin-7(8<i>H</i>)-yl]-1-(2,4,5-trifluorophenyl)butan-2-amine], a potent dipeptidyl peptidase 4 inhibitor, were evaluated in male Sprague-Dawley rats beagle dogs. plasma clearance volume distribution higher (40–48 ml/min/kg, 7–9 l/kg) than dogs (∼9 ∼3 l/kg), its half-life was shorter rats, ∼2 h compared with ∼4 Sitagliptin absorbed...
Trace level genotoxic impurities (GTIs) in pharmaceutical products require precise, accurate, and robust analytical methodologies for their analysis control. The need to control most the low ppm combination with very often reactive labile nature of presents significant challenges. This article reports a systematic GTI method development strategy (MDS) based on our successful experiences recent years quality by design (QbD) principles emphasizing expected performance being built into method....
The present work demonstrates, for the first time, application of mass spectrometric kinetic method quantitative chiral purity determination by automatic flow-injection MS/MS. particular compound analyzed is GSK2251052A, a novel boron-containing systemic antibiotic treatment multidrug-resistant Gram-negative bacterial infections. Chiral recognition and quantitation GSK2251052A was achieved based on competitive dissociation kinetics Cu(II)-bound trimeric complex [Cu(II)(A)(ref*)2-H](+) (A =...
An online sample extraction chiral bioanalytical method was developed and validated for the quantification of terbutaline, a beta2-selective adrenoceptor agonist, spiked into human plasma by using two columns stationary phase (CSP) in conjunction with liquid chromatography tandem mass spectrometry (LC-MS/MS). In this method, Oasis HLB were used parallel purification Chirobiotic T CSP enantiomeric separation. Atmospheric pressure chemical ionization MS/MS employed multiple reaction monitoring...
Abstract A method with parallel extraction columns and analytical (PEC‐PAC) for on‐line high‐flow liquid chromatography/tandem mass spectrometry (LC/MS/MS) was developed validated simultaneous quantification of a drug candidate its six metabolites in dog plasma. Two were used sample two separation analysis. The plasma samples, after addition an internal standard solution, directly injected onto the PEC‐PAC system purification This allowed use one analyte while other being equilibrated....
The pharmacokinetics and metabolism of the l-threo isoleucine thiazolidide dipeptidyl peptidase IV inhibitor, di-[2<i>S</i>,3<i>S</i>]-2-amino-3-methyl-pentanoic-1,3-thiazolidine fumarate (ILT-threo) its allo stereoisomer (ILT-allo) were evaluated in rats, dogs, monkeys. Both compounds well absorbed (>80%) all species, most dose (>60%) was recovered urine. Metabolites identified species included a sulfoxide (M1), sulfone (M2), carbamoyl glucuronide (M3). For both compounds, parent drug...