## 1 Introduction
Traditionally, yarrow essential oil is obtained by steam distillation, but novel extraction techniques have also been implemented, such as ultrasound-assisted extraction [16] or supercritical CO\({}_{2}\) extraction [17; 18]. [PERSON] and [PERSON] compared the essential oil composition obtained from _Achillea millifolium_ L. by hydrodistillation to that obtained by supercritical CO\({}_{2}\) extraction. It was observed that less volatile components were present in higher quantities in the case of CO\({}_{2}\) extraction, while the yield of monoterenes was higher when hydrodistillation was applied. This phenomenon is caused by the incomplete separation of monoterenes from gaseous CO\({}_{2}\)[17]. In a recent study, [PERSON] et al. evaluated the phytochemical profiles of natural deep eutectic solvent (NADES)-based extracts obtained by ultrasound-assisted extraction with those obtained using conventional solvents: 80% ethanol, 80% methanol, and water. In the case of alcoholic and aqueous extractions, the bioactive compounds, chlorogenic acid, isomers of dicaffeoylquinic acids, and flavonoids were the most abundant bioactive compounds [19]. In n-hexane and diethyl-ether extracts, [PERSON] et al. identified germacrene D, viridiflorol, \(\alpha\)-Thujone, \(\beta\)-thujone trans-sabinene hydrate, and 1.8-cineole as major components. In comparison to the distilled material, the extraction process using non-polar solvents resulted in increased amount of higher-molecular-weight volatile compounds, with more sesquiterpenes than monoterepenes [20]. During steam distillation, on the effect of heat and water, the prozaulene achillicin is transformed through chamazulenic acid into chamazulene, which confers the characteristic blue color to yarrow essential oil [21]. The yield of distillation was reported to vary based on different factors. [PERSON] et al. investigated the effect of distillation time in the 0.5-3 h interval. The increase in yield along with an increase in the relative amount of chamazulen was reported at prolonged distillation times [6]. The presence of numerous compounds with various biological activities can explain the wide spectrum of pharmacological effects that have been attributed to _Achillae milliglolium_ L., such as analgesic, anti-inflammatory, antidiabetic, chologogue, spasmolytic, antitumor, antioxidant, antifungal, and antiseptic activities [22; 23]. In traditional European medicine, it is used in the treatment of inflammatory and spasmodic gastro-intestinal complaints and hepato-biliary disorders and as an appetite-enhancing drug [3], but also in menstrual irregularity, to relieve menstrual cramps and pain, and for the healing of wounds and ulcers [24]. According to the European Medicines Agency (EMA)'s herbal monographs on _Achillae milliglolium_ L.--_herba_ and _Achillae milliglolium_ L.--_fos_, their well-established use could be considered as scientifically proven to treat temporary loss of appetite; mild, spasmodic gastro-intestinal complaints, including bloating and flatulence; treatment of minor spasms associated with menstrual periods; and the treatment of small superficial wounds [25; 26]. In the biomedical field, recent research work was directed toward elucidating the anti-inflammatory effects of essential oil [27] and its efficacy in the treatment of peptic ulcers [28] and ulcerative colitis [29]. [PERSON] et al. reported that chondrocytes were protected during chamazulene treatment against IL-1\(\beta\)-induced osteoarthritic inflammation [30]. [PERSON] et al. described the antitumor potential of the plant [31]. Given the sensitivity of several components of essential oil to environmental conditions [32], appropriate formulation and conditioning are required to prevent degradation and assure the long-term preservation of its specific composition [33]. In many cases, the transformation of essential oil from a liquid state into free-flowing and easily manageable dry powders might be of fundamental importance to fit a specific application [34]. For this purpose, [PERSON] et al.