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Acta Chromatographica
Authors:
M. Malesevic
,
L. Zivanovic
,
A. Protic
,
M. Radisic
,
M. Lausevic
,
Z. Jovic
, and
M. Zecevic

Summary

The present study was designed to characterize the possible degradation products of zolpidem tartrate under various stress conditions according to International Conference on Harmonization (ICH) guidelines Q1A(R2). After exposure to light, heat, hydrolysis, and oxidation, the drug significantly degraded under photolytic and acid/base hydrolytic conditions. Degradation resulted in the formation of four key degradants. Degradation products were resolved from each other and the drug by employing an isocratic elution method on Luna C18 column with mobile phase consisting of methanol-10 mM ammonium acetate (68.4:31.6, v/v), wherein pH was adjusted to 5.4 with glacial acetic acid. To characterize the degradation products, a method was extended to LC-MS and a mass fragmentation pattern was established using single quadrupole. The degradants were identified as zolpacid, oxozolpidem, zolpaldehyde, and zolpyridine. Finally, the most possible degradation mechanism of zolpidem tartrate in different environments was proposed.

Open access

Summary

The objective of the present study was to report the stability of novel antiviral drug, valganciclovir based on the information obtained from forced degradation studies. Valganciclovir was subjected to forced hydrolytic (acidic, alkaline and neutral), oxidative, photolytic and thermal stress in accordance with the ICH guideline Q1A (R2). The drug showed labiality under only acidic and photoacidic conditions while it was stable to other stress conditions. Resolution of the drug and degradation products was achieved on a Hypersil Gold C-18 column (4.6 × 250 mm, 5 μm) utilizing acetonitrile (A) and potassium dihydrogen ortho phosphate buffer (pH 5.0; 0.01M) in the ratio of 5:95 (v/v) at a flow rate of 0.6 ml/min and at the detection wavelength 252 nm. The major acidic stress degradation product was characterized by LC-MS/MS and its fragmentation pathway was proposed. Validation of the LC-DAD method was carried out in accordance with ICH guideline. The method met all required criteria and was applied for analysis of commercially available tablets.

Open access

shortening of drug-susceptible and XDR-TB [ 16 ]. In the current work, we conducted studies to characterize the potential for a pharmacokinetic interaction between pretomanid and pyrazinamide in rats using LC-MS/MS. We have developed and validated an LC-MS

Open access

using ultra-high performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS). In the present study, we established a simple, sensitive, and rapid liquid chromatography (LC)–MS/MS method and validated for determination of PH in dog plasma

Open access
Acta Chromatographica
Authors:
Jelena Dzudovic
,
Milkica Crevar Sakac
,
Marko Antunovic
,
Aleksandra Repic
,
Slobodan Obradovic
,
Snezana Djordjevic
,
Jelena Savic
, and
Boris Dzudovic

[ 10 ]. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is one of the most sensitive analytical methods for the detection, identification and quantification of analyzed compounds on biological samples. Literature survey reveals that

Open access
Acta Chromatographica
Authors:
Tiantian Lu
,
Xiaohong Wang
,
Qi Zhang
,
Kun Liu
,
Tongxin Xu
,
Quande Wang
,
Pengfei Zhao
, and
Zhongzhe Cheng

chromatography-tandem mass spectrometry (LC-MS/MS) method were developed, respectively [ 9 , 11 ]. However, there is little bioanalytical method for the determinatin of solasodine in urinary and fecal samples. In addition, bioanalysis of urine is commonly

Open access

antihyperlipidemic drugs was necessary to achieve the treatment goals in plasma lipid levels. A low dose of statins in combination with EZE achieves comparable or even greater LDL cholesterol reduction than a very-high-dose of statins [ 1 ]. Different LC-MS

Open access
Acta Chromatographica
Authors:
Hao-ran Dai
,
Ya-hui Hu
,
Jia-yi Long
,
Ying Xia
,
Hong-li Guo
,
Jing Xu
,
Xuan-sheng Ding
,
Jing Chen
,
Xiao-peng Lu
, and
Feng Chen

Method Internal standard Matrix Matrix volume (μL) Sample preparation Elution Column Mobile phase Linearity range (ng mL −1 ) Analytical time (min) Reference 2015 LC-MS/MS ER-167615 Plasma 100 LLE by MTBE Isocratic YMC-Pack Pro C8 column (50 × 3.0 mm) 0

Open access

determination of PG can be found in the literature. Liquid chromatography coupled with a tandem mass spectrometer (LC-MS/MS) is preferable method due to its selectivity, accuracy, precision, and robustness [ 13–15 ]. Some of the published methods require a

Open access

ng/mL and an elimination half-life of about 8 h [ 4 ]. Literature survey revealed that LCZ has been reported to be determined by ultraviolet (UV) spectrophotometry [ 3 , 5 ], liquid chromatography–tandem mass spectrometry (LC–MS/MS) in human plasma

Open access