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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 2:05 |
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Conference: Bucharest University Faculty of Physics 2010 Meeting
Section: Biophysics and Medical Physics;Electricity and Magnetism
Title:
Optical Characterization of Quinazoline Derivatives Stability
Authors:
Andra Militaru 1, Adriana Smarandache 1, Abdallah Mahamoud 2, Victor Damian 1, Sandrine Alibert 2, Mihail-Lucian Pascu 1, Jean-Marie Pagès 2
Affiliation:
1National Institute for Laser, Plasma and Radiation Physics, Magurele, 077125, Bucharest, Romania
2UMR-MD1, Faculté de Pharmacie, Université Méditerranée, IFR88, Marseille, France
E-mail
andra.militaru@inflpr.ro
Keywords:
quinazoline derivatives, time stability, UV-Vis spectroscopy
Abstract:
The stability of quinazoline derivative, BG1188, having the formula C12H14N4O3, was characterized using UV-Visible absorption spectroscopy.
Quinazolines are important for their pharmaceutical properties. The time evolution reveals for how long a medicine is stable and can be administered according to the recommended medical procedures.
BG1188 solutions in ultrapure water and DMSO were studied. Although several concentrations of BG1188 were studied, 10-3M was preferred because at this concentration quinazoline derivatives exhibit higher antibacterial activity.
For the BG1188 in ultrapure water the reproducibility of the spectra is remarkably good since the peak values vary within the measurements errors. The results show that the BG1188 solutions in ultrapure water are stable for time intervals up to 2856 hours.
The absorption spectra of BG1188 in DMSO varied from the first hours of measurements. Between 360 hours and 650 hours the spectra show stability characteristics within the experimental errors.
The absorption measurements performed between 10-6M and 2x10-3M concentrations of BG1188 in ultrapure water allowed to compute a polymerization degree of 1.018; this means that for all the experiments only the monomer form of BG1188 was present.
Although the degree of polymerization indicated that in BG1188 solutions there were present only monomers, aggregation phenomena take place that produce precipitates in the form of thin wires, of a broad range of dimensions (lengths and diameters) and shapes observed initially with the naked eye. At later stages, these wires mould into aggregates/clusters. The images of the aggregates which are shown were obtained using an optical microscope working in reflection or transmission. The wire like formations are produced gradually, starting from the first hours of the solutions preparation regardless the BG1188 concentration or solvent; they are built from spherical, micrometric and even sub-micrometric formations which develop connections leading to the wire-like shapes and are very stable with temperature.
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