Determination of Thujone

Following the previously proposed new European Pharmacopoeia (Ph. Eur.) chapter 2.8.27. Determination of Estragole a second new Ph. Eur. chapter 2.8.28. Determination of Thujone has been published in Pharmeuropa 37.4. Comments on the proposed new text for the "Methods in Pharmacognosy" section of the Ph. Eur. are open until 31 December 2025.

Background

Thujone is found in a number of medicinal plants and their essential oils, such as, common sage, tansy, and wormwood. The substance is considered neurotoxic in high doses. According to a report of EMA's Committee on Herbal Medicinal Products (HMPC) on the use of herbal medicinal products (HMPs) containing thujone, daily thujone intake from medicinal products should be less than 6 mg.

The proposed analytical procedure (gas chromatography) provided in the new Ph. Eur. general chapter 2.8.28. is intended to be used for the quantitative determination of Thujone in herbal drugs and herbal drug preparations. It has been validated for clary sage oil, (cut) sage leaf (Salvia officinalis), three-lobed sage leaf, sage tincture and Spanish sage oil. However, its suitability for other herbal drugs or herbal drug preparations must be demonstrated; otherwise, an alternative validated method must be used.

For more information please go to Pharmeuropa online.