TY - JOUR
T1 - Reaction between drug substances and pharmaceutical excipients
T2 - formation of citric acid esters and amides of carvedilol in the solid state
AU - Larsen, Jesper
AU - Cornett, Claus
AU - Jaroszewski, Jerzy Witold
AU - Hansen, Steen H
N1 - Keywords: Carvedilol; Citric acid; Solid-state reaction; LC-MS; NMR
PY - 2009
Y1 - 2009
N2 - The reactivity of citric acid towards drug substances in the solid state was examined using the beta-blocker carvedilol as a model compound. The reaction mixtures were analysed by LC-MS, the reaction products were isolated by preparative HPLC, and the structures were elucidated by microprobe NMR spectroscopy. Heating a mixture of solid carvedilol and solid citric acid monohydrate for 96h at 50 degrees C resulted in the formation of about 3% of a symmetrical ester as well as of a number of other reaction products in smaller amounts. Formation of the symmetrical ester was also observed at room temperature. At 70 degrees C, the amounts of three isomeric esters formed reached 6-8%. The minor reaction products were citric acid amides, O-acetylcarvedilol, and esters of itaconic acid.
AB - The reactivity of citric acid towards drug substances in the solid state was examined using the beta-blocker carvedilol as a model compound. The reaction mixtures were analysed by LC-MS, the reaction products were isolated by preparative HPLC, and the structures were elucidated by microprobe NMR spectroscopy. Heating a mixture of solid carvedilol and solid citric acid monohydrate for 96h at 50 degrees C resulted in the formation of about 3% of a symmetrical ester as well as of a number of other reaction products in smaller amounts. Formation of the symmetrical ester was also observed at room temperature. At 70 degrees C, the amounts of three isomeric esters formed reached 6-8%. The minor reaction products were citric acid amides, O-acetylcarvedilol, and esters of itaconic acid.
KW - Former Faculty of Pharmaceutical Sciences
U2 - 10.1016/j.jpba.2008.09.039
DO - 10.1016/j.jpba.2008.09.039
M3 - Journal article
C2 - 18996664
SN - 0731-7085
VL - 49
SP - 11
EP - 17
JO - Journal of Pharmaceutical and Biomedical Analysis
JF - Journal of Pharmaceutical and Biomedical Analysis
IS - 1
ER -