Department of Pharmaceutical Technology, Faculty of Pharmacy, Fluminense Federal University, Rua Dr. Mário Viana, 523, Santa Rosa, Niterói 24.241-000, RJ, Brazil
Dr. Deborah Quintanilha Falcão
Department of Pharmaceutical Technology, Faculty of Pharmacy, Fluminense Federal University, Rua Dr. Mário Viana, 523, Santa Rosa, Niterói 24.241-000, RJ, Brazil
Nanotechnology has emerged as a promising area for innovative products, including insecticides. Dengue is a tropical disease which is considered a critical health problem in developing countries, due to negative impacts to the environment caused by synthetic chemicals used for vector control (Aedes aegypti). Thus, developing of natural products based insecticidal are considered very promising. On this context, the aim of the present study was to obtain an O/W nanoemulsion containing Rosmarinus officinalis L., Lamiaceae, essential oil and evaluate its larvicidal activity against A. aegypti. Low energy method was employed, allowing achievement of small droplets. The nanoemulsion also presented low polydispersity and mean droplet below 200nm, even after 30 days of storage. Potential mortality levels were observed after 24h (80±10%) and 48h (90±10%) in A. aegypti larvae at final concentration of 250ppm, related to R. officinalis essential oil. This study contributes to nanobiotechnology of natural products, presenting a potential larvicidal nanoemulsion prepared with R. officinalis essential oil. Moreover, nanoemulsion production involved a non-heating procedure, describing easy technique which may be useful for integrative control programs
Plants have been recognized as a good source of insecticidal agents, since they are able to produce their own defensives to insect attack. Moreover, there is a growing concern worldwide to develop pesticides with low impact to environment and non-target organisms. Hexane-soluble fraction from ethanolic crude extract from fruits of Manilkara subsericea and its triterpenes were considered active against a cotton pest (Dysdercus peruvianus). Several natural products with insecticidal activity have poor water solubility, including triterpenes, and nanotechnology has emerged as a good alternative to solve this main problem. On this context, the aim of the present study was to develop an insecticidal nanoemulsion containing apolar fraction from fruits of Manilkara subsericea.
Essential oils are used primarily as natural preservatives, flavourants and fragrances in cosmetic products. Several pharmacopeias possess monographs of plants which are good sources of essential oils, such as Brazilian Pharmacopeia, including Illicium verum Hook. f., Schisandraceae and Rosmarinus officinalis. Since determination of Hydrophile-Lipophile Balance (HLB) value of essential oils appears as a critical step for development of emulsions and other semi-solid formulations, evaluation of required HLB values for I. verum and R. officinalis essential oils is the aim of this study. They were obtained by hydrodistillation and several emulsions were prepared by changing emulsii ers. The couple sorbitan oleate/polysorbate 20 provided best emulsions and was used at different ratios, at a total blend concentration of 5% w/w. The lowest mean droplet diameters for R. officinalis and I. verum emulsions were obtained at HLB 16.5 (97.12nm) and 16.7 (246.6nm), respectively. Moreover, emulsions with R. officinalis were i ner and presented some bluish rel ection, characteristic of nanoemulsions. The lowest turbidity value for R. officinalis emulsion was also obtained at HLB 16.5 (0.33). Thus, the present study describes for the first time HLB values for R. officinalis (16.5) and I. verum (16.7) essential oils, contributing to their physicochemical characterization and technology development of phytopharmaceutical