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Guaco is a traditional medicinal plant that was not previously object of studies within this area, despite its great commercial importance and crop production. To our knowledge, few efforts were carried out for a method that simultaneously extract plant material and generate nano-dispersions. Extraction of leaves with surfactant aqueous solutions allowed obtention of nano-dispersions with mean droplet size and polydispersity index below 300 nm and 0.3, respectively. Zeta potential was around – 30 mV. Chemical analysis indicated that guaco chemical marker (coumarin) was extracted. Guaco nano-dispersion was considered effective against cytotoxic effects induced by cyclophosphamide and significantly reduced micronucleated polychromatic erythrocytes frequency. Moreover, it presented improved bioactivity, when compared to guaco ethanolic extract obtained by classical method. Considering the several advantages of simultaneous extraction/nanoformulation methodology, including reducing costs and quickness of nano-dispersion preparation, the present study successfully used a simple, low-energy method and ecofriendly approach. © 2019 Elsevier B.V., Authors would like to thank CNPQ (Rede Amazônica de Pesquisa em Biofármacos – 407768/2013-0) and FAPEAP (Prodetec Araguari – process nº 250.203.035/2013) for the financial support, INCAPER (Instituto Capixaba de Pesquisa, Assistência Técnica e Extensão Rural) for the plant material and FAPES (Fundação de Amparo a Pesquisa do Espírito Santo) for the pos-graduate grant of the mastering student (first author).

Andiroba (Carapa guianensis) seeds are the source of an oil with a wide range of biological activities and ethnopharmacological uses. However, few studies have devoted attention to innovative formulations, including nanoemulsions. The present study aimed to obtain a colloidal system with the andiroba oil using a low-energy and organic-solvent-free method. Moreover, the preliminary residual larvicidal activity of the nanoemulsion against Aedes aegypti was evaluated. Oleic and palmitic acids were the major fatty acids, in addition to the phytosterol β-sitosterol and limonoids (tetranortriterpenoids). The required hydrophile-lipophile was around 11.0 and the optimal nanoemulsion was obtained using polysorbate 85. The particle size distribution suggested the presence of small droplets (mean diameter around 150 nm) and low polydispersity index (around 0.150). The effect of temperature on particle size distribution revealed that no major droplet size increase occurred. The preliminary residual larvicidal assay suggested that the mortality increased as a function of time. The present study allowed achievement of a potential bioactive oil in water nanoemulsion that may be a promising controlled release system. Moreover, the ecofriendly approach involved in the preparation associated with the great bioactive potential of C. guianensis makes this nanoemulsion very promising for valorization of this Amazon raw material. © 2017 Flávia L. M. Jesus et al., he authors thank FAPEAP (Prodetec Araguari, Process no. 250.203.035/2013) and MarketPlace LAC/Brazil, Suriname University/Embrapa Amapá (Process Funarbe 9740, ID 552) for the financial support, Karen Mustin for her English revision of the manuscript, and CAPES for the student scholarship awarded to the first author. They also thank Pro-Rectory of Cooperation and Interinstitutional of the Amapá Federal University Relations for the international mobility grant to Dr. Caio Pinho Fernandes and thank the Group of Colloidal and Interfacial Chemistry of the Institute for Advanced Chemistry of Catalonia (IQAC-CSIC) for receiving him and the student Fernanda Borges de Almeida.

The species Drimys angustifolia Miers and D. brasiliensis Miers, commonly known as “casca-de-anta”, have in their leaves essential oils that can confer cytotoxic effects. In this study, we evaluated the citotoxic effects of the volatile oils from these two species. We also proposed a nanoemulsion formulation for each of the species and assessed the in vitro cytotoxicity on U-138 MG (human glioblastoma) and T24 (human bladder carcinoma) cell lines. The plant chemical composition was evaluated by gas chromatography coupled to mass spectrometer. Furthermore, the nanoemulsions were prepared and characterized. Our results showed that; bicyclogermacrene (19.6%) and cyclocolorenone (18.2%) were the most abundant for the D angustifolia oil and D brasiliensis oil, respectively. Both nanoemulsions, D angustifolia and D brasiliensis appeared macroscopically homogeneous and opalescent bluish liquids, with nanometric mean diameters of 168 nm for D brasiliensis and 181 nm for D angustifolia. The polydispersity indices were below 0.10, with an acid pH of 4.7–6.3, and negative zeta potentials about -34 mV. The results of transmission electron microscopy showed that droplets are present in the nanometer range. Only the D brasiliensis oil was efficient in reducing the cell viability of both U-138 MG (42.5% ± 7.0 and 67.8% ± 7.8) and T24 (33.2% ± 2.8, 60.3% ± 1.6 and 80.5% ± 8.8) cell lines, as assessed by MTT assay. Noteworthy, similar results were obtained with cell counting. Finally, D brasiliensis oil incubation caused an increase of annexin-V and propidium iodite population, according to evaluation by cytometry analysis, what is characteristic of late apoptosis. The results presented herein lead us to consider the potential therapeutic effects of the essential oils and nanoformulations as novel strategies to inhibit tumor growth. Key words: bladder carcinoma, Drimys angustifolia, Drimys brasiliensis, essential oils, glioblastoma, nanoemulsions

This study reports the development of nanoemulsions intended for intravenous administration of thalidomide (THD). The formulations were prepared by spontaneous emulsification method and optimized with respect to thalidomide (0.01–0.05%, w/w), and hydrophilic emulsifier (polysorbate 80; 0.5–4.0%, w/w) content. The formulations were evaluated concerning physical appearance and drug crystallization; droplet size; zeta potential and drug assay. Only the formulation containing 0.01% THD and 0.5% polysorbate kept its properties in a satisfactory range over the evaluated period (60 days), i.e. droplet size around 200nm, drug content around 95% and zeta potential around −30mV. The transmission electron microscopy revealed emulsion droplets almost spherical in shape confirming the results obtained by photon correlation spectroscopy. Drug crystallization observed for higher content (THD 0.05%, w/w) nanoemulsions was investigated. The crystals observed at optical microscopy presented a different crystal habit compared to that of the raw material used. It was speculated whether the kind of THD polymorph employed could influence nanoemulsion formulation. Formulations were prepared with either one of THD polymorphs (β- or α-) and crystals were characterized by fourier transformed infrared spectroscopy (FTIR) and X-ray diffraction (XRD). It was observed that regardless of the polymorph employed (β- or α-), drug crystallization occurs in the α-form. THD solubility in oils was not influenced by the polymorphic form. In addition, the in vitro dissolution profile of the selected formulation (THD 0.01%, w/w; polysorbate 0.5%, w/w) was assessed by bulk-equilibrium reverse dialysis sac technique and demonstrated a release profile similar to that of a THD acetonitrile solution, with around 95% THD being dissolved within 4h. Finally, a pharmacokinetic simulation of an intravenous infusion of 250mL of the selected nanoemulsion suggests that the parenteral administration of a dose as low as 25mg might lead to therapeutic plasma concentrations of thalidomide.