Electrokinetic studies of alkaline solutions of oxalic acid, cystine and tyrosine across urinary bladder membranes have been made. Data have been analysed in the light of non-equilibrium thermodynamics. Maximum energy conversion efficiency (ηmax), kinetic energy term (α1) and polarization term (α2) have been computed. It has been found that ηmax., α1, and α2, etc., are maximum for uric acid among the permeants used. Since ηmax, and α1 and α2 are related with membrane interface, such studies are relevant in understanding the comparative effect of permeants on bladder interface.