The aim of the present study was to formulate non-ionic surfactant vesicles of frusemide to enhance its skin permeation and to develop a transdermal therapeutic system using provesicular approach. The effect of various formulation variables on the transdermal flux, amount of drug deposited in skin, and plasma level of drug were studied. The skin permeation studies were conducted on rat skin and human skin for quantification of permeation parameters. With PGS3 formulation [Span 40:soyalecithin:cholesterol (4.5:4.5:1)], the plasma level in the rats had reached to a level of 0.42 +/- 0.13 microg/mL at the sampling interval of 4 hr and remained within the therapeutic concentration range (1.66-0.3 microg/mL) for the next 12 hr. Results showed that proniosomal formulation was able to sustain the drug level in the blood and offer a promising means for non-invasive delivery of frusemide.