03.14.13
US Patent No. 8,114,386 B2; 3M Innovative Properties Company, St. Paul, MN, has patented a single phase, surfactant-free, topical insect repellent composition. It is comprised of an effective amount of one or more film-forming methyl vinyl ether-maleic acid monobutyl or monoethyl ester copolymers comprising neutralized carboxylic acid groups; an effective amount of one or more insect repellents selected from the group consisting of sec-butyl 2-(2-hydroxyethyl)piperidine-1-carboxylate, ethyl N-butyl-N-acetyl-3-aminopropionate, N,N-diethyl-meta-toluamide, p-menthane-3,8-diol, and mixtures thereof; an effective amount of one or more water miscible organic solvents selected from the group consisting of ethanol, 1-propanol, isopropanol and mixtures thereof; and water.