Solubilized System of Caffeine using Mixed Hydrotropy of Niacinamide and Vanillin

AbstractThis study aimed to provide a guide prescription for anti-cellulite cosmetics by establishing optimalconditions for dissolving high contents of caffeine while lowering the concentration of hydrotropes usingmixed hydrotropy that combines niacinamide and vanillin. To set up the optimal condition for dissolvingcaffeine in water at 25℃, niacinamide and vanillin were added while maintaining the mixing ratio ofniacinamide and vanillin at 1.0 : 2.0, 1.0 : 1.5, 1.0 : 1.0, 1.5 : 1.0, and 2.0 : 1.0 until the caffeine wascompletely dissolved, and this result was compared with the minimum hydrotrope concentration (MHC)of a single hydrotrope. For dissolving 3%, 5%, 7%, and 10% of caffeine, the MHC of vanillin was 0.4632%,1.4037%, 2.4993%, and 4.1173%, respectively, and the total hydrotrope concentration of mixed hydrotropywas 0.5821%, 1.7867%, 2.8566%, and 4.8159%, respectively, when the mixing ratio of niacinamide andvanillin was 1.0 : 2.0. In other words, the total hydrotrope content of the mixed hydrotropy was lower thanthe MHC of niacinamide but higher than the MHC of vanillin. However, vanillin can cause discolorationand odor, we propose the use of mixed hydrotropy to have the advantages of each hydrotrope andminimize the disadvantages by lowering the MHC of a single hydrotrope.