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Lippia sidoides (Verbenaceae) is a medicinal plant from Northeastern Brazil, whose essential oil is rich in thymol, being a well-known antimicrobial phenol compound. The aim of this study was to produce suspensions of polycaprolactone (PCL)-coated nanocapsules incorporated with the essential oil from the L. sidoides leaves (EOLS) by the emulsion-diffusion method. EOLS nanocapsules were prepared by mixing EOLS and PCL with Kolliphor P 188® as the surfactant and ethyl laurate (core oil), all of them in varying concentrations (1, 2.5 and 5%). The said nanoformulations were assessed for their particle size and encapsulation efficiency (EE). The best condition was achieved with the nanoformulation containing 1% Kolliphor P 188®, 2.5% polycaprolactone, 2.5% EOLS and 5% ethyl laurate, emulsified at 10,000 rpm for 5 min, which presented an average particle diameter with 173.6 nm, a polydispersity index of 0.2 and an EE of 70.6%. Additionally, the nanoemulsion was characterized by the nuclear magnetic resonance (1H and diffusion-ordered NMR spectroscopy- DOSY), scanning electron microscopy, thermogravimetry and the differential scanning calorimetry. Furthermore, the suspension of nanocapsules of the EOLS was demonstrated to be stable at 5 °C during 60 days of storage in an accelerated stability study.

Phyllanthus amarus Schum & Thonn is an herb rich in bioactive compounds, mainly phenols, and it is widely used for its medicinal properties. In this study, aqueous extraction from aerial parts of P. amarus was performed using ultrasound-assisted extraction (UAE), pressurized liquid extraction (PLE), and conventional extraction (CE). Response surface methodology was used to assess the effect of the time, ultrasonic intensity, and liquid/solid (L/S) ratio in UAE and of time and temperature in PLE on total phenolics and gallic acid extraction. The chemical composition of the extracts obtained through the three techniques was also analyzed using UPLC-ESI-QTOF-MS/MS. The UAE operational condition that afforded the highest phenolic content (27.23 mg/g plant) used time of 7 min, ultrasonic intensity of 301 W/cm2, and L/S ratio of 40 mL/g. This value was lower than the one obtained by the conventional extraction method (42.78 mg/g plant). However, PLE at 192.4 °C and time of 15 min yielded the highest total phenolic content (52.97 mg/g plant). Regarding the extraction of gallic acid, the non-conventional methods yielded contents three times higher than the conventional extraction. The chemical composition of P. amarus extracts had mainly hydrolysable tannins, flavonoids, and lignans. The most significant difference was found in UAE, which proved to be inefficient to extract ellagitannins.