An improved adhesive patch for long-term collection of sweat.

An improved adhesive patch is described, capable of collecting sweat continuously at a steady rate for periods up to ten days. Four normal subjects wore duplicate patches applied to the skin above the outer ankle and the collecting pads were weighed every second day for ten days. Uptake was linear in all patches (r2 = 0.99) and the uptake rate varied from 18.38 to 47.01 mg/day (mean = 27.18 mg/day, equivalent to 0.71 mg/cm2/hour). Several drugs are excreted in the sweat, and this patch has potential applications as a tool to monitor drug-taking behavior.