## 1 Introduction  
The identification of medicinal plants rich in compounds with an antioxidant effect, such as polyphenols that have the greatest capacity to capture free radicals, has been of particular interest for research since ancient times [1; 2; 3]. Over time, antioxidants extracted from plants marketed in the form of crude extracts or medicines derived from plant products have been used as alternative medications for prophylactic or curative purposes to maintain health [4; 5]. Natural antioxidants are much more effective and safer for the body than synthetic antioxidants. They can be included in different dermatological cosmetics formulations for antiaging and photoprotective effects, in various dietary supplements, and pharmaceutical formulations [3; 4; 5; 6]. To date, the _Ruta graveolens_ L. plant, which has a high content of phenolic compounds, such as flavonoids, and antioxidant effects has been little studied in terms of the use of its hydroalcoholic extracts in pharmaceutical formulations. In this paper, we attempt to produce pharmaceutical particulate systems in the form of microspheres loaded with the hydroalcoholic extract of _Ruta graveolens_ L. intended for oral administration. The _Ruta graveolens_ L. plant is also known as rue or herb-of-grace and is part of the _Rutaceae_ family, _Rutales_ order. It is a perennial herbaceous, dicotyledonous, aromatic, and endemic plant in Eastern and South-Eastern Europe, but has gradually spread to Southern Europe, the subtropical area, the African coast of the Mediterranean Sea, and the sub-spontaneous flora of Dobrogea [7; 8; 9; 10; 11]. _Ruta graveolens_ L. (RG) has been attracting significant attention in the field of drug discovery in recent years due to the presence of various compounds, including flavonoids, in its extract that are known to have curative properties and can be used to treat different diseases, including inflammatory conditions [13; 14]. [PERSON], [PERSON] et al. demonstrated that the aqueous and ethanolic extracts of RG have inhibitory effects on lipoxygenase enzymes and on human plural fluid phospholipase A2 (HPF-PLA2) [14]. [PERSON], [PERSON] et al., found that the RG methanolic extract had the ability to inhibit albumin denaturation and membrane stabilization [15]. Some studies [15; 16] suggest that its extracts could be useful, including in the treatment of irritable bowel syndrome, as they have antispasmodic and anti-inflammatory properties. The roots and aerial parts of the RG plant contain more than 120 active compounds, including rutin, also known as rutoside. Rutin is considered by some authors to be the main flavonoid compound found in the plant. It has been shown to possess antioxidant and anti-inflammatory properties, and is also the most commonly occurring glycosidic flavone across the plant kingdom [8; 17; 18; 19]. Research has demonstrated that administering rutin orally can enhance colitis in rats induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) by inhibiting the activation of nuclear factor kappa B (NF&B) induced by pro-inflammatory cytokines, such as TNF-\(\alpha\)[20]. In this study, the plant extract was encapsulated in microspheres, because microencapsulation is a technique that involves incorporating liquid, solid, and gaseous substances into carriers to protect them from decomposition and improve their stability [21; 22]. Among the microencapsulation methods that can be used, in this work, complex coacervation was used because is a low-cost, flexible, and rapid method [23]. Compared with other encapsulation methods, it produces microparticles with higher microencapsulation efficiency by usinga high core load and low wall material concentration [24]. The process is initiated by the electrostatic interaction between two biopolymers with opposite charges [25] in an aqueous medium, leading to the formation of two or more partially immiscible liquid phases with the aggregation of colloidal particles [26]. Microparticles can be produced from walls of natural, synthetic, or semi-synthetic polymeric material.