The soft-drug 1 (R= Me, Et) and pro-soft-drug 3 have been prepared as models of topical anti-psoriatic β-adrenergic agonists. The chemical hydrolysis of 3 proceeded via the acid 18 with a maximum stability at apparent pH∼ 4.0. In the presence of PLCE, the required metabolism of 3 to the soft-drug 1 (R= Et) was achieved, which slowly degraded to the dihydroxy acid 2. Soft-drug 1 (R= Et) was poorly transported across a silicone membrane, ...
