Three lidocaine topical systems 1.8% are applied to mid-lower back for 12 hours. Subjects are instructed to exercise 30 minutes on an exercise bicycle, achieving at heart rate of approximately 108 bpm. Exercise is performed after 2.5 hours, 5.5 hours, and 8.5 hours after topical system application.

Three lidocaine topical systems 1.8% are applied to mid-lower back for 12 hours. A heating pad is applied for 20 minutes at 2.5, 5.5, and 8.5 hours after the product is applied.

Three lidocaine topical systems 1.8% are applied to mid-lower back for 12 hours. No heat application or exercise is performed during this period.

Peak plasma concentration of lidocaine after application of 3 patches for 12 hours

Area under the plasma concentration versus time curve from 0 to 48 hours of lidocaine in plasma

Area under the plasma concentration versus time curve from 0 to infinite time of lidocaine in plasma

Adhesion to skin assessed by FDA 0-4 scoring system. The scoring for adhesion of patches is indicated as follows: 0 = ≥ 90% Adhered (essentially no lift off the skin), 1 = ≥ 75% to < 90% Adhered (some edges only lifting off the skin), 2 = ≥ 50% to < 75% Adhered (less than half of the patch lifting off the skin), > 0% to < 50% Adhered but not detached (more than half of the patch lifting off the skin without falling off), and 4 = 0% adhered (patched completely detached). The cumulative adhesion score is calculated as the sum of scores at each assessment time point.

Product tolerability is assessed by Dermal Response Score. The application site is evaluated 30 minutes and 2 hours after product removal (12.5 and 14 hours post-dose, respectively). Response score from 0 to 7; 0= No evidence of irritation, 1= Minimal erythema, barely perceptible, 2= Definite erythema, readily visible; minimal edema or minimal papular response, 3= Erythema and papules, 4= Definite edema, 5= Erythema, edema and papules, 6= Vesicular eruption, 7= Strong reaction spreading beyond test (i.e., application) site.