Reliable on-line sample preparation of basic compounds from plasma using a reversed phase restricted access media in column-switching LC.

Eiichi Yamamoto; Hatsue Igarashi; Yoshiaki Sato; Ikuo Kushida; Takashi Kato; Takashi Kajima; Naoki Asakawa

doi:10.1016/j.jpba.2006.05.021

Home/Archive/PubMed

PubMed · 16828251

Reliable on-line sample preparation of basic compounds from plasma using a reversed phase restricted access media in column-switching LC.

Eiichi Yamamoto·Hatsue Igarashi·Yoshiaki Sato·Ikuo Kushida·Takashi Kato·Takashi Kajima·Naoki Asakawa

View original source ↗Export metadata ↓

Abstract

We investigated on-line sample preparation of basic compounds from plasma using a methylcellulose-immobilized reversed-phase restricted-access media in column-switching liquid chromatography (LC). Dilution of the plasma sample with phosphate buffered saline prevented or delayed the formation of fibrin clots at 4 degrees C and resulted in reproducible on-line sample preparation over a 30-h period. The use of an ion-pair reagent in the extraction LC enhanced recoveries of hydrophilic basic compounds. The ability of the methods to quantify compounds in plasma were validated and the method was successfully applied to the pharmacokinetic study of a hydrophilic basic compound injected into the bloodstream of rats.

Explore related subjects

Acetonitriles Animals Autoanalysis Chromatography, High Pressure Liquid Drug Design Fluorocarbons Injections, Intravenous Male Methylcellulose Molecular Structure Pharmaceutical Preparations Rats Rats, Sprague-Dawley Reproducibility of Results Sensitivity and Specificity Journal Article

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Eiichi Yamamoto, Hatsue Igarashi, Yoshiaki Sato, Ikuo Kushida, Takashi Kato, Takashi Kajima, Naoki Asakawa. 2006-07-07. Reliable on-line sample preparation of basic compounds from plasma using a reversed phase restricted access media in column-switching LC.. https://doi.org/10.1016/j.jpba.2006.05.021

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2007

Intermolecular electron transfer from excited benzophenone ketyl radical.

The electron transfer from the benzophenone ketyl radical in the excited state (BPH(.-)(D(1))) to several quenchers (Qs) was investigated using nanosecond/picosecond two-color two-laser flash photolysis and nanosecond/nanosecond two-color two-laser flash photolysis. The electron transfer from BPH(.-)(D(1)) to Qs was confirmed by the transient absorption and fluorescence quenching measurements. The intermolecular electron-transfer rate constants were determined using the Stern-Volmer analysis. The driving force dependence of the electron-transfer rate was revealed.

Acetonitriles↗

PubMed2007

Single-ion solvation free energies and the normal hydrogen electrode potential in methanol, acetonitrile, and dimethyl sulfoxide.

The division of thermodynamic solvation free energies of electrolytes into contributions from individual ionic constituents is conventionally accomplished by using the single-ion solvation free energy of one reference ion, conventionally the proton, to set the single-ion scales. Thus, the determination of the free energy of solvation of the proton in various solvents is a fundamental issue of central importance in solution chemistry. In the present article, relative solvation free energies of ions and ion-solvent clusters in methanol, acetonitrile, and dimethyl sulfoxide (DMSO) have been determined using a combination of experimental and theoretical gas-phase free energies of formation, solution-phase reduction potentials and acid dissociation constants, and gas-phase clustering free energies. Applying the cluster pair approximation to differences between these relative solvation free energies leads to values of -263.5, -260.2, and -273.3 kcal/mol for the absolute solvation free energy of the proton in methanol, acetonitrile, and DMSO, respectively. The final absolute proton solvation free energies are used to assign absolute values for the normal hydrogen electrode potential and the solvation free energies of other single ions in the solvents mentioned above.

Acetonitriles↗

PubMed2007

A validated stability indicating LC method for oxcarbazepine.

The present paper describes the development of a stability indicating reversed phase liquid chromatographic (RPLC) method for oxcarbazepine in the presence of its impurities and degradation products generated from forced decomposition studies. The drug substance was subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal degradation. The degradation of oxcarbazepine was observed under base hydrolysis. The drug was found to be stable to other stress conditions attempted. Successful separation of the drug from the synthetic impurities and degradation product formed under stress conditions was achieved on a C18 column using mixture of aqueous 0.02 M potassium dihydrogen phosphate-acetonitrile-methanol (45:35:20, v/v/v) as mobile phase. The developed HPLC method was validated with respect to linearity, accuracy, precision, specificity and robustness. The developed HPLC method to determine the related substances and assay determination of oxcarbazepine can be used to evaluate the quality of regular production samples. It can be also used to test the stability samples of oxcarbazepine.

Acetonitriles↗