Evaluation of Caffeine Gels on Physicochemical Characteristics and In Vivo Efficacy in Reducing Puffy Eyes

The eyelids are the thinnest skin in the body, leading to be easy for the blood vessels to show through the skin caused a swollen and dark appearance called puffy eyes. Placing refrigerated damp tea bags on the eyelids has been believed for a long time that it can reduce the puffy eyes due to the vasoconstriction of caffeine. This study aimed to characterize physicochemical properties and to determine in vivo efficacy in reducing puffy eyes of the prepared caffeine gels. The formulation composed of 3% caffeine, 2% ethanol, 0.3% Uniphen P-23, 7.5% propylene glycol, 0.5% Carbopol Ultrez-21 and water to 100% was selected for eye irritation test and efficacy evaluation since it possessed good characteristics and provided sustained skin permeation. The 34 volunteers (18 women, 16 men) who easily developed puffy eyes after going to bed without sleep and with no irritation to caffeine gel as well as its gel base were treated with the gels in a randomized, double-blind, placebo-controlled trial. The skin permeation profiles showed that all caffeine gels allowed caffeine to permeate through the newborn pig skin. However, the overall efficacy of the selected caffeine gel in reducing puffy eyes was not significantly different from that of its gel base. It could be concluded that the cooling effect of the hydrophilic gels was the main parameter in reduction of eye puffiness rather than the vasoconstriction of caffeine.