FIELD OF THE INVENTION

[01 ] The present invention refers to a Natural Repellent Against the Aedes aegypti Mosquito for topical use in the form of cream-gel, having application in the cosmetic area, obtained from an O/W type emulsion containing the hydroalcoholic extract of Neem leaves {Azadirachta indica, A. Juss) and Babassu oil {Orbignya phalerata, Martins) aiming to repel mosquitoes such as Aedes sp., Anopheles sp., Culex sp., among others.

BACKGROUND OF THE INVENTION

[02] Dengue, as well as Zica, are diseases that can be transmitted by the Aedes aegypti mosquito. This mosquito has diurnal habit, black color with white stripes and it is cosmopolitan (Taveira et al., Man. Cont. Aedes aegypti. Ribeirao Preto. City Hall. 2001 ).

[03] Nowadays, repellent products available on market use as base the DEET (N,N-diethyl-3-methylbenzamide) (patent WO 201 1 /095991 of 201 1 , belonging to Soni Saurabh Sureshchandra). Since 1954, it was presented as a superior active repellent compared to others (Journal of Organic Chemistry, v. 19, p. 493, 1954). It is effective and protects up to 8 hours (Abiy et al. Malaria Journal. 2015. 4:187), but it presents risks to human health (Oliveira, Master thesis USP, Sao Paulo, p.1 08, 2008).

[04] According to the Brazilian National Health Surveillance Agency (ANVISA, CATEC-Technical Opinion No. 2, from November 1 1 , 2006), repellents containing said substance cannot be used on children under 2 years, and on children being from 2 to 12 years the number of applications of the product shall not exceed 3 times a day, due to the toxic risk. In this sense, there are alternatives such as the use of a safer repellent, as it possibly is the case of natural origin products, whose short period of protection is compensated by the possibility of several reapplications (Oliveira, Master thesis USP, Sao Paulo, p.108, 2008), as the present invention.

[05] Some natural repellents present as constituents: citronella (Patent PI 1 106861 -2 of 2012, belonging to the Universidade Federal de Juiz de Fora) and Neem oil combined with other oils (US Patent 20150373996, belonging to William R. Williams, II), which are used as mosquito repellents and among them, Aedes aegypti, for example. However, as disadvantages, it can be highlighted that the combined use with other oils can result in a greasy and unpleasant feeling, besides of not providing moisturizing properties to the skin.

[06] In order to solve these problems, it is proposed the present invention, which presents the Neem extract as repellent agent and the Babassu oil as the substance having moisturizing action. The cream-gel type emulsion has excellent spreadability, adherence and provides moisture to the skin, besides of not causing any toxic hazard to man.

DETAILED DESCRIPTION OF THE INVENTION

[07] The present invention refers to a natural repellent against the Aedes aegypti mosquito which contains an O/W type emulsion containing the following components 0.4 to 1 .6 g of acryloyldimethyltaurate sulfonic acid copolymer and neutralized vinylpyrrolidone being preferentially 0.8 g; 1 .0 to 4.0 g of ethoxylated sorbitan monolaurate 20 EO, being preferably 2 g; 1 .0 to 4.0 g of Babassu oil {Orbignya phalerata, Martius) being preferably 2 g; 0.15 to 0.6 g of aqueous solution of methylisothiazolinone being preferentially 0.3 g; 1 .0 to 4.0 g of hydroalcoholic extract of Neem leaves {Azadirachta indica, A. Juss) being preferably 2 g; 1 .0 to 4.0 g of glycerol being preferably 2 g; 1 .0 to 4.0 g of isopropyl alcohol being preferably 2 g, and a percentage of distilled water sufficient to complete the emulsion to 100 g.

[08] The natural repellent against the Aedes aegypti mosquito, which refers the present invention, uses the O/W emulsion prepared by phase inversion method that consists of pouring the oily phase directly in the aqueous phase under constant stirring prepared according to the following steps:

(1 ) In the oily phase, it is used ethoxylated sorbitan monolaurate 20 EO, aqueous solution of methylisothiazolinone and the Babassu oil placed in a 100 imL glass beaker and homogenized at room temperature (25 ± 2 °C);

(2) In the aqueous phase, in other 100 imL glass beaker, it is placed glycerol, isopropyl alcohol, hydroalcoholic extract of Neem leaves and distilled water (q.s.) and homogenized at room temperature (25 ± 2 °C);

(3) The components of the aqueous phase are poured into the oily phase and kept under constant stirring in a digital mechanical shaker (Fisatam Ltda - Mod. 713 D) until the complete homogenization of both phases.

[09] The hydroalcoholic extract of Neem leaves used in the formulation of the present invention was obtained as described in the patent application PI 1003892-2 of 2010, owned by Universidade Estadual do Maranhao, and added in natural repellent formulation against the Aedes aegypti mosquito, in a proportion of 1 to 25% (m/m). For obtaining such extract, Neem leaves must be collected; subsequently, the material shall be submitted to the drying process, being exposed on a bench, in a dry and well- ventilated place. Then, dried in a stove at 45 °C. After complete drying the material is shredded and weighted. To the obtained powder, it was added 70% alcohol (EtOHihteO) in the ratio of 1 :3, wherein the macerated should be filtered in filter paper or gauzes and it must be made from 1 to 10 extractions every 72 hours, for obtaining the hydroalcoholic extract of Neem leaves, and at the end it is rotary-evaporated, for elimination of the solvent, remaining at balloon only the concentrated Neem extract. Then, the concentrated extract must be conditioned under cooling at 4 to 6 °C and stored in glass jar until its use. Such concentrated extract is added to the formulation of the repellent in proportion of 1 to 25% (m/m).

[010] The Babassu oil used in natural repellent against Aedes aegypti mosquito should be extracted mechanically, manually or by solvent from the fruit kernels.

[01 1 ] The present invention consists of a natural repellent of topical use, which presents slightly yellowish color, characteristic odor, appearance of cloudy yellow gel-cream, homogeneous and remain stable after centrifugation.

[012] Such natural repellent against the Aedes aegypti mosquito presents pH between 5.04 and 5.27 during 30 days stored at room temperature (25 ± 2 °C). And, when subjected to thermal stress (40 ± 2 °C), it presents pH variation of around 5.03 to 5.42, which are acceptable values to human skin.

[013] The natural repellent against the Aedes aegypti mosquito presents viscosity at room temperature (25 ± 2 °C) between 1 .43 and 1 .63 and when subjected to thermal stress (40 ± 2 °C), it presents viscosity around 1 .38 to 4.37, thus demonstrating features of a gel-cream formulation with good spreadability on the skin.

[014] The natural repellent proposed in the present invention has repellent properties to Aedes sp., Anopheles sp., Culex sp. mosquitoes, among others and moisturizing properties due to the use of Babassu vegetable oil.