Stability of chosen beta-adrenolytic drugs of different polarity in basic environment
Kwiecień, A.; Krzek, J.; Zylewski, M.
Journal - Association of Official Analytical Chemists 91(2): 322-331
2008
ISSN/ISBN: 0004-5756 PMID: 18476343 Document Number: 615487
The stability of atenolol, acebutolol, and propranolol was investigated in sodium hydroxide solutions at concentrations of 0.1, 0.3, 0.5, and 1 M at 3 temperatures ranging from 37 to 95 degrees C. The degradation processes that occurred in drugs under investigation were described with kinetic parameters (k, t(0.1), and t(0.5)) and energy of activation (E,). It was found that the stability of the drugs increased toward lipophilic propranolol in the assumed experimental model. The rate constants k decreased, contrary to t(0.1), t(0.5), and E-a, which varied comparably to log P (partition coefficient), thus increasing from the most hydrophilic atenolol, through acebutolol of lower polarity, to the most lipophilic propranolol. The identification of degradation products was performed with the application of proton nuclear magnetic resonance spectrometry and thin-layer chromatography-densitometry and data from the literature.