INVITRO PERCUTANEOUS-ABSORPTION OF THIAMINE DISULFIDE FROM A MIXTURE OF PROPYLENE-GLYCOL AND FATTY-ACIDS

The in vitro percutaneous transport of thiamine disulfide (TDS), an oxidized dimer of thiamine, from propylene glycol through excised abdominal rat skin was studied. The application of saturated, long-chain fatty acids [stearic acid (18:0), myristic acid (14:0), and lauric acid (12:0)] as enhancers to the system was also studied. TDS permeated through rat skin from propylene glycol with a flux of 2.5 +/- 0.8-mu-g/cm2/min. The flux was enhanced 31 times by 12:0 and 1.4 times by 14:0 and was suppressed to 80% of its original value by 18:0. The absorption of TDS could not be explained by TDS permeating across a dialysis membrane, but the interaction between TDS and fatty acids may influence the system. The results show the possibility of developing a transdermal thiamine delivery system.