Desenvolvimento de sistemas dispersos contendo extrato de Shinus terebinthifolius: ensaios preliminares

Abstract

Schinus terebinthifolius Raddi (Anacardiaceae), popularly known as “aroeira,” is a medicinal plant native to South America, widely distributed along the Brazilian coast. According to the pharmacopoeial monograph, it contains secondary metabolites such as anacardic acids, terpenes, flavonoids, and derivatives of gallic acid [1]. Pharmacological studies have demonstrated a significant anti-inflammatory activity for the hydroalcoholic extract of this species [2], which has encouraged the development of pharmaceutical systems for its delivery. Emulsion systems facilitate the incorporation of alcoholic extracts, as they are composed of a mixture of lipid components and an aqueous phase stabilized by surfactants. Thus, the aim of this study was to develop a nanoemulsion system containing hydroalcoholic extract of *S. terebinthifolius* for oral administration. The system developed consisted of oleic acid (OA), polyethylene glycol 400, poloxamer 407, preservative, hydroalcoholic extract of *S. terebinthifolius* Raddi, and distilled water. The preparation method was carried out under cold conditions using an Ultra-Turrax® T-18 homogenizer. The formulations were evaluated for particle size (PS) and polydispersity index (PdI) using a Zetasizer Nano ZS (detection angle of 173°; 25 °C), with analyses performed weekly, in triplicate, over 21 days. The formulations were subjected to mechanical stress (3000 rpm for 3 min) and thermal stress (room temperature (RT) and refrigeration (R)) [3]. The mean PS values for formulations containing extract were: 181.12 ± 10.14 nm (STA) and 205.90 ± 11.59 nm (SR); for formulations without extract, 257.72 ± 21.82 nm (BTA) and 281.78 ± 17.47 nm (BR). The PdI values were: 0.195 ± 0.005 and 0.256 ± 0.057 for STA and SR, respectively. For BTA and BR, the values were 0.256 ± 0.013 and 0.279 ± 0.026, respectively. Statistical analysis revealed no significant differences (p ≥ 0.05) among the replicates of the STA formulation for both PS and PdI. The BTA formulation showed significant differences (p ≤ 0.05) between replicates BTA-1 and BTA-2, and between BTA-1 and BTA-3, for both PS and PdI values. In formulations stored under refrigeration, SR exhibited significant differences (p ≤ 0.05) in PS values between SR-1 and SR-3, and between SR-2 and SR-3. However, no differences were observed in PdI values among replicates containing extract (p ≥ 0.05). For the BR formulation, significant differences (p ≤ 0.05) were observed between replicates BR-2 and BR-3, for both PS and PdI. The results demonstrated the development of a formulation with nanometric PS suitable for oral administration, with acceptable PdI under both temperature conditions evaluated. Nevertheless, visual observations revealed the presence of an “oily film” on some formulations, which, although not leading to major instability phenomena, indicate the need for more detailed studies of the formulations.