Powder formulation containing insect repellent
The present invention relates to a powder formulation comprising at least one insect repellent and magnesium hydroxide carbonate, and to a process for the preparation of the formulation and to the use of the formulation for repelling insects.
1. A powder formulation comprising (a) at least one insect repellent selected from the group consisting of N,N-diethyl-m-toluamide, ethyl 3-(N-butylacetamino)propionate, 1-(1-methylpropoxycarbonyl)-2-(2-hydroxyethyl)piperidine, citronella oil and andiroba oil and (b) magnesium hydroxide carbonate, wherein the magnesium hydroxide carbonate has a bulk density of at most about 200 g/l, the weight ratio of magnesium hydroxide carbonate to insect repellent in the formulations is 2:1 to 1:1 and the formulation comprises 5 to 20% by weight of the at least one insect repellent, based on the total weight of the formulation.
2. The powder formulation according to claim 1 , wherein the at least one insect repellent is ethyl 3-(N-butylacetamino)propionate.
3. A powder formulation comprising (a) at least one insect repellent selected from the group consisting of N,N-diethyl-m-toluamide, ethyl 3-(N-butylacetamino)propionate, 1-(1-methylpropoxycarbonyl)-2-(2-hydroxyethyl)piperidine, citronella oil and andiroba oil and (b) magnesium hydroxide carbonate, wherein the magnesium hydroxide carbonate has a bulk density of at most about 130 g/l.
4. The powder formulation according to claim 1 , which comprises 5 to 10% by weight, based on total weight of formulation, of the at least one insect repellent.
5. The powder formulation according to claim 4 , which comprises 10 to 20% by weight, based on the total weight of the formulation, of the at least one insect repellent.
6. The powder formulation according to claim 1 , which comprises 5 to 40% by weight, based on the total weight of the formulation, of magnesium hydroxide carbonate.
7. The powder formulation according to claim 6 , which comprises 5 to 30% by weight, based on the total weight of the formulation, of magnesium hydroxide carbonate.
8. The powder formulation according to claim 1 , wherein the weight ratio of magnesium hydroxide carbonate to insect repellent in the formulation is 2:1 to 1.5:1.
9. The powder formulation according to claim 8 , wherein the weight ratio of magnesium hydroxide carbonate to insect repellent in the formulation is 1.5:1 to 1:1.
10. The powder formulation according to claim 1 , which furthermore comprises one or more ingredients selected from the group consisting of cereal starch, rice starch, maize starch, modified starch, mica, synthetic mica, boron nitride, titanium dioxide, talc, aluminium oxide, bismuth oxychloride, PMMA, nylon and silica.
11. A process for preparing the powder formulation according to claim 1 , comprising mixing the at least one insect repellent with the magnesium hydroxide carbonate and any further ingredients.
12. A process for repelling insects, comprising repelling insects by applying to the skin of a host a powder formulation according to claim 1 .
13. The powder formulation according to claim 1 , wherein the at least one insect repellent is ethyl N,N-diethyl-m-toluamide.
14. The powder formulation according to claim 1 , wherein the at least one insect repellent is 1-(1-methylpropoxycarbonyl)-2-(2-hydroxyethyl)piperidine.
15. The powder formulation according to claim 1 , wherein the at least one insect repellent is citronella oil.
16. The powder formulation according to claim 1 , wherein the at least one insect repellent is andiroba oil.