On-line electrochemistry/electrospray ionization mass spectrometry (EC-ESI-MS) system for the study of nucleosides and nucleotides oxidation products
Publication date: 5 September 2018Source: Journal of Pharmaceutical and Biomedical Analysis, Volume 158Author(s): Sylwia Studzińska, Lena Siecińska, Bogusław BuszewskiAbstractThe main aim of present investigation was to study the oxidation products of nucleosides and nucleotides with the use of on-line electrochemistry/electrospray ionization mass spectrometry (EC-ESI-MS) system. The conditions applied in the system were optimized in complex manner, involving study of the impact of working electrodes or sample solvent on the oxidation of tested compounds and their ionization in mass spectrometry. Finally 5 mM of ammonium acetate was used selected and pH 3 was used for positive ionization mode, while pH 7 was applied for negative ionization in mass spectrometry. It was shown that utilization of both ionization modes is indispensable in order to detect and identify all of oxidation products. Furthermore the identification of compounds obtained using the EC-ESI-MS system was done and results were compared with known metabolites of studied compounds. These products are associated with specific disease states, or may be a potential metabolites. Moreover the analysis of urine samples by liquid chromatography coupled with mass spectrometry confirmed the possibility of using EC-ESI-MS technique to simulate the metabolism of nucleosides and nucleotides, since the oxidation products have also been identified in urine samples.
Conclusions: Results reveals that developed nitrendipine nanoemulsion gel overcomes the limitation of low penetration and accentuate permeation through albino Wistar rat skin. It was concluded that nanoemulsion gel could be utilized as a potential carrier for transdermal delivery of nitrendipine. PMID: 31976777 [PubMed - as supplied by publisher]
Authors: Rezaie Shirmard L, Ghofrani M, Bahari Javan N, Bayrami S, Tavassoli A, Rezaie A, Amini M, Kebriaee-Zadeh A, Rouini MR, Dinarvand R, Rafiee-Tehrani M, Dorkoosh FA Abstract Uncontrolled distribution of nanoparticles (NPs) within the body can significantly decrease the efficiency of drug therapy and is considered among the main restrictions of NPs application. The aim of this study was to develop a depot combination delivery system (CDS) containing fingolimod loaded poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) NPs dispersed into a matrix of oleic acid-grafted-aminated alginate (OA-g-AAlg) to minimize ...
Authors: Yoshida T, Sako K, Kondo H Abstract High consumption of oil formulations has been reported to reduce the blood exposure of drugs like tacrolimus. Consumption of oil formulations has also been shown to inhibit T-cell production of interleukin-2 (IL-2) compared to solid dispersion formulations (SDFs). However, a large amount of oil causes gastrointestinal side effects such as diarrhea and low compliance. Here, we investigated the feasibility of reducing the amount of oil and substitution of chemically synthetized oils for natural oils in these formulations. Reducing the amount of sunflower oil increased bloo...
CONCLUSIONS: In conclusion, the potential for supersaturation in LBDDS, and the risk of precipitation, was found to be highly drug dependent. The apparent degree of supersaturation was considered a major factor impacting the ability to maintain drug supersaturation upon storage. PMID: 31975613 [PubMed - as supplied by publisher]
Authors: Mailhot Vega RB, Hoppe BS PMID: 31976780 [PubMed - as supplied by publisher]
With a second case of a deadly Chinese virus confirmed in the United States, and four cases under investigation in New York, Buffalo-area hospitals are on alert and preparing as best as they can. The novel coronavirus was first identified in Wuhan, China, in December. More than 850 cases have since been reported worldwide, with more than 40 deaths in China. Transportation has been shutdown with travel restricted for millions in that country as international officials work to contain the di sease. In…
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