scholarly journals Quantification of Niacin and Its Metabolite Nicotinuric Acid in Human Plasma by LC-MS/MS: Application to a Clinical Trial of a Fixed Dose Combination Tablet of Niacin Extended-Release/Simvastatin (500 mg/10 mg) in Healthy Chinese Volunteers

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Pingping Zhang ◽  
Yantong Sun ◽  
Guobing Shi ◽  
Yin Sui ◽  
Qiuying Li ◽  
...  
Keyword(s):  
Human Plasma ◽  
Extended Release ◽  
Internal Standard ◽  
Negative Ion ◽  
Fixed Dose ◽  
Ionization Source ◽  
Combination Tablet ◽  
Dose Combination ◽  
Relative Errors ◽  
Negative Ion Mode

Our paper aimed to develop rapid, sensitive, and specific LC-MS/MS method for the quantification of niacin (NA) and its metabolite nicotinuric acid (NUA) in human plasma. Following protein precipitation with acetonitrile, the NA, NUA, and internal standard (5-fluorouracil) were separated on a Zorbax 300SB-C8column (250 mm × 4.6 mm, 5 μm) with a mobile phase consisting of methanol-2 mM ammonium acetate (3 : 97, v/v) at a flow rate of 1 mL/min (split 1 : 1). A tandem mass spectrometer equipped with electrospray ionization source was used as the detector and operated in negative ion mode. The linear concentration ranges of the calibration curves were 5–800 ng/mL for NA and NUA. The intra-assay RSD for quality control (QC) samples were from 5.0% to 8.7% for NA, and 5.5% to 7.6% for NUA. The interassay RSD for QC samples were from 2.8% to 9.4% for NA, and 3.7% to 5.8% for NUA. The relative errors for QC samples were from −2.2% to 2.3% for NA, and −0.6% to 3.2% for NUA. The method was successfully applied to the investigation of the pharmacokinetic profiles of NA, NUA in human after single dose administration of Niacin extended-release/Simvastatin tablet (500 mg/10 mg).

A Stable Fixed-dose Combination Tablet of Pseudoephedrine and KOB Extracts for the Extended Release

Drug Research ◽  
2013 ◽  
Vol 63 (11) ◽  
pp. 572-578 ◽  
Author(s):  
C.-J. Hwang ◽  
M.-H. Park ◽  
H.-W. Jung ◽  
Y.-K. Park ◽  
Y.-H. Kim ◽  
...  
Keyword(s):  
Extended Release ◽  
Fixed Dose Combination ◽  
Fixed Dose ◽  
Combination Tablet ◽  
Dose Combination

scholarly journals Liquid Chromatography/Tandem Mass Spectrometry for the Simultaneous Determination of Ursodiol and its Major Metabolites, Tauroursodeoxycholic Acid and Glycoursodeoxycholic Acid in Human Plasma

2012 ◽  
Vol 9 (3) ◽  
pp. 1605-1612
Author(s):  
M. Ganesan ◽  
S. Nanjundan ◽  
S. Viswanathan ◽  
G. Uma
Keyword(s):  
Human Plasma ◽  
Solid Phase ◽  
Internal Standard ◽  
Bioequivalence Study ◽  
Negative Ion ◽  
Limit Of Quantification ◽  
Tauroursodeoxycholic Acid ◽  
Liquid Chromatography Tandem Mass ◽  
Glycoursodeoxycholic Acid ◽  
Negative Ion Mode

A rapid and sensitive method is described for the quantification of ursodiol and its major metabolites glycoursodeoxycholic acid (GUDCA) and tauroursodeoxycholic acid (TUDCA) in human plasma using single internal standard (Ursodeoxycholic Acid d4). Solid phase extraction was performed and chromatographic separation of 5µL injected sample was achieved using Waters Xterra, 5µm column with a mobile phase comprised of methanol and 5 mM ammonium formate with 0.1 % acetic acid ( 70 : 30, v/v ). The mass spectrometer was used in negative ion mode and multiple reactions monitoring using electro spray ionization mode as an interface. The method was fully validated and the calibration curves were linear over the concentration range of 25.9 to 15300.1 ng/mL for ursodiol, 2.7 to 1587.5ng/mLfor tauroursodeoxycholicacid and 25.4 to 15040.9 ng/mL for glycoursodeoxycholic acid. The method was sensitive and specific, with the lower limit of quantification of 25.9, 2.7 and 25.4 ng/ml for ursodiol, tauroursodeoxycholic acid and glycoursodeoxycholic acid respectively. The present method includes a simple and rapid sample preparation with shorter analysis run time and less flow rate compared to previously reported methods. The method was applied successfully for a bioequivalence study in healthy subjects.

scholarly journals Fast Sensing of Hydrogen Cyanide (HCN) Vapors Using a Hand-Held Ion Mobility Spectrometer with Nonradioactive Ionization Source

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5045
Author(s):  
Victor Bocos-Bintintan ◽  
Ileana Andreea Ratiu
Keyword(s):  
Ion Mobility ◽  
Hydrogen Cyanide ◽  
Limit Of Detection ◽  
Chemical Warfare Agent ◽  
Source Model ◽  
Negative Ion ◽  
Industrial Chemicals ◽  
Ionization Source ◽  
Toxic Industrial Chemicals ◽  
Negative Ion Mode

Sensitive real-time detection of vapors produced by toxic industrial chemicals (TICs) always represents a stringent priority. Hydrogen cyanide (HCN) is definitely a TIC, being widely used in various industries and as an insecticide; it is a reactive, very flammable, and highly toxic compound that affects the central nervous system, cardiovascular system, eyes, nose, throat, and also has systemic effects. Moreover, HCN is considered a blood chemical warfare agent. This study was focused toward quick detection and quantification of HCN in air using time-of-flight ion mobility spectrometry (ToF IMS). Results obtained clearly indicate that IMS can rapidly detect HCN at sub-ppmv levels in air. Ion mobility spectrometric response was obtained in the negative ion mode and presented one single distinct product ion, at reduced ion mobility K0 of 2.38 cm2 V−1 s−1. Our study demonstrated that by using a miniaturized commercial IMS system with nonradioactive ionization source model LCD-3.2E (Smiths Detection Ltd., London, UK), one can easily measure HCN at concentrations of 0.1 ppmv (0.11 mg m−3) in negative ion mode, which is far below the OSHA PEL-TWA value of 10 ppmv. Measurement range was from 0.1 to 10 ppmv and the estimated limit of detection LoD was ca. 20 ppbv (0.02 mg m−3).

OPTIMISATION AND VALIDATION OF HPLC METHOD FOR SIMULTANEOUS QUANTIFICATION OF RIFAMPICIN, ISONIAZID, PYRAZINAMIDE, AND ETHAMBUTOL HYDROCHLORIDE IN ANTI-TUBERCULOSIS 4-FDC TABLET

2015 ◽  
Vol 77 (1) ◽  
Author(s):  
Sholihul Khoiri ◽  
Sudibyo Martono ◽  
Abdul Rohman
Keyword(s):  
High Performance ◽  
Phosphate Buffer Solution ◽  
Gradient Elution ◽  
Hplc Method ◽  
Fixed Dose ◽  
Buffer Solution ◽  
Solution Ph ◽  
Combination Tablet ◽  
Simultaneous Quantification ◽  
Dose Combination

High-performance liquid chromatography (HPLC) method has been developed and validated for the simultaneous quantification of four components, namely rifampicin (RIF), isoniazid (INH), pyrazinamide (PYR), and ethambutol hydrochloride (ETM), contained in anti-tuberculosis drugs in fixed dose combination tablet (4-FDC). In order to increase the sensitivity of EMB, the pre-column derivatization technique with phenethyl isocyanate (PEIC) was carried out. The separation was accomplished using Waters Symmetry C8 (250× 4.6 mm i.d.; 5 μm) at 30oC. The mobile phase used was a mixture of acetonitrile and 20 mM phosphate buffer solution (pH 6.8) containing triethylamine and delivered at 1.5 mL/minute using gradient elution. TheUV detector was set at 210 nm. The method was validated in terms of selectivity, linearity, accuracy, precision, detection limit, quantification limit, and robustness according to International Conference on Harmanization (ICH). The optimized method is succcesfully used for quantitative analysis of RIF, INH, PYR and ETM in 4-FDC tablets. The level of these drugs in 4-FDC tablets were in accordance to that specified in Indonesian pharmacopeia.

scholarly journals Bioequivalence of a Fixed-Dose Combination Tablet of the Complete Two-Drug Regimen of Dolutegravir and Rilpivirine for Treatment of HIV-1 Infection

2018 ◽  
Vol 62 (9) ◽  
Author(s):  
Rashmi Mehta ◽  
Allen Wolstenholme ◽  
Kristin Di Lullo ◽  
Caifeng Fu ◽  
Shashidhar Joshi ◽  
...  
Keyword(s):  
Statistical Power ◽  
Drug Regimen ◽  
Fixed Dose Combination ◽  
Fixed Dose ◽  
Combination Tablet ◽  
Reference Treatment ◽  
Dose Combination ◽  
Hiv 1 ◽  
Test Treatment ◽  
Separate Tablets

ABSTRACTA complete 2-drug regimen of dolutegravir at 50 mg and rilpivirine at 25 mg was approved to treat HIV-1 infection in virologically suppressed patients after demonstrating acceptable efficacy and tolerability. This study investigated the bioequivalence and pharmacokinetics of the fixed-dose combination tablet compared with those of separate tablets. Secondary endpoints were the tolerability and safety of the fixed-dose combination tablet. In this open-label, randomized-sequence, 2-way crossover trial, single doses of the fixed-dose combination tablet (the test treatment) and the combination of separate tablets (the reference treatment) were administered to healthy adults after a moderate-fat meal, with a 21-day washout between treatments. Pharmacokinetic samples were collected through 12 days after dosing. The primary endpoints were the area under the plasma concentration-time curve (AUC) and the maximum concentration of drug in plasma (Cmax). The study employed a prespecified sample size reestimation based on a blind midpoint review ofCmaxvariability to update the enrollment size to achieve statistical power. Of 118 participants enrolled, 113 received both treatments and underwent pharmacokinetic assessment. The 90% confidence intervals for the geometric least-squares mean ratios for the AUC from 0 h to infinity, the AUC from 0 h to the last quantifiable measurement, andCmax(test treatment versus reference treatment) were within the bioequivalence range of 0.80 to 1.25 for both drugs, indicating bioequivalence. In this study, a single dose of either treatment was well tolerated overall, with 4% (n= 5) and 3% (n= 3) of participants reporting adverse events considered related to the test and reference treatments, respectively. The dolutegravir-rilpivirine fixed-dose combination tablet is bioequivalent to a combination of separate tablets, and no new safety signals emerged. (This study has been registered at ClinicalTrials.gov under identifier NCT02741557.)

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