A study on the in-vitro percutaneous absorption of propranolol from disperse systems

Transdermal administration of propranolol can be used to avoid hepatic firs t-pass metabolism of the drug. The effect of polysorbate 80 concentration o n the permeation of propranolol incorporated into micelles of polysorbate 8 0 in water, oil-in-water microemulsions of isopropyl myristate-polysorbate 80-sorbitol-water and oil-in-water emulsions of isopropyl myristate-polysor bate 80-sorbitan monooleate-water has been investigated by use of an artifi cial double-layer membrane, composed of a barrier foil and a lipid barrier, in Franz-type diffusion cells. Reversed-phase high-performance liquid chro matography, with celiprolol as internal standard, was used to determine the concentration of propranolol in the receptor compartment and a logarithmic equation was used to estimate the apparent permeability coefficient of pro pranolol from disperse systems. For each disperse system the apparent permeability coefficient of propranol ol decreased with increasing polysorbate 80 concentration. Moreover, for a given polysorbate 80 concentration the apparent permeability coefficient of propranolol increased when the disperse system was changed from emulsion t o microemulsion and then to solubilized system, because of the increasing i nterfacial area of total disperse phase. The results show that transdermal permeation of propranolol is greater when it is diffused from solubilized systems rather than from microemulsions or emulsions.