Subjects were randomised into three dose groups of equal size. The three dose groups were 100mM (2.82mg/100μl), 200mM (5.64mg/100μl) and 400mM (11.28mg/100μl). Before wounding, three prospective wound sites 1cm long were marked on the upper, inner aspect of each arm (anterior, posterior and distal) to give three pairs of wounds. Wounds were assigned as Pair 1 (left distal and right distal), Pair 2 (left anterior and left posterior) and Pair 3 (right anterior and right posterior).