On the Stability of Sesquiterpene Lactones in the Officinal Arnica Tincture of the German Pharmacopoeia¹

Abstract

An investigation of sesquiterpene lactone content in Arnica tincture (German Pharmacopoeia) after storage for three years at different temperatures (+ 4, + 25 and + 30 °C) was carried out by GC and GC-MS analysis. A decrease (13, 32 and 37 %, respectively) in the content of the main active compounds in this preparation, 11α,13-dihydrohelenalin esters, correlating with storage temperature was found. This change was shown to be caused by addition of ethanol to the cyclopentenone structure of these molecules leading to 2-ethoxy-2,3,11,13-tetrahydrohelenalin derivatives.

References

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