PROBLEM TO BE SOLVED: To avoid the side effects of aspirin by increasing the dissolubility of acetyl salicylic acid in gastric juice as well as by increasing the permeability of aspirin through membrane and skin barrier which would make the percutaneous administration of aspirin possible (topical application).SOLUTION: We have synthesized a novel positively charged prodrug, represented by formula (1), of acetyl salicylic acid and an analogue thereof. The positively charged amino group of the prodrug not only greatly increases the dissolubility of the drug, but binds to the negative charge on the phosphate head group of the membrane and pushes the prodrug into the cytosol and the prodrug, acetic acid diethylaminoethyl acetyl salicylate, diffuses through human skin about 400 times faster than acetyl salicylic acid per se, and about 100 times faster than ethyl acetyl salicylate.SELECTED DRAWING: Figure 2