A comparative in vitro study of percutaneous penetration of beta-blockers in human skin.

In vitro diffusion experiments with propranolol, oxprenolol, metoprolol and atenolol were carried out using excised human abdominal skin. The main permeation parameters (permeability coefficient, flow and lag time) were calculated and compared as measurement of intrinsic permeability across human skin. A long lag time and a low steady-state flow were found for all drugs assayed. Skin permeability predicted at steady state did not reach therapeutic concentrations, which indicated the need for appropriate chemical penetration enhancers or vehicles to overcome limiting factors. The results, including those of celiprolol and bisoprolol reported previously, correlated with physicochemical properties, especially with lipophilicity, one of the main factors in drug permeability prediction through human skin.