thiamine-disulfide and lauric-acid

The permeation and accumulation of lauric acid (12:0) in rat skin as an enhancer for the percutaneous absorption of thiamine disulfide (TDS), using propylene glycol as a vehicle, were determined in vitro. 12:0 barely permeated through skin, and accumulated in skin. The accumulated amount increased increasing concentrations in the vehicle (1-20%). The proportion of the accumulation to total dose was highest at a dose of 5%. A positive relationship was found between the accumulated amount of TDS and 12:0. It was suggested that the penetration of 12:0 into skin contributes to the enhanced partition of TDS to skin.

Topics: Animals; Lauric Acids; Male; Propylene Glycols; Rats; Rats, Wistar; Skin Absorption; Stimulation, Chemical; Thiamine

The effect of long chain fatty acid (FA) and its analogs on the accumulation of thiamine disulfide (TDS) in rat skin using propylene glycol as a vehicle was studied in vitro. Lauric acid (12:0) increased the accumulation of TDS in skin, while myristic acid and stearic acid caused a slight decrease in accumulation. Lauryl alcohol and lauric acid methyl ester did not change the accumulation of TDS in the skin. The ratio of the amount of TDS accumulated in skin to the solubility of TDS in the vehicle increased dependent on the concentration of 12:0 added in the vehicle. It was suggested that the increase in the permeability coefficient of TDS by 12:0 results from the enhanced transport of TDS from the vehicle to skin.

Topics: Animals; Chromatography, High Pressure Liquid; Dodecanol; In Vitro Techniques; Laurates; Lauric Acids; Male; Myristates; Rats; Rats, Wistar; Skin Absorption; Solubility; Structure-Activity Relationship; Thiamine

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 micrograms/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.

Topics: Administration, Cutaneous; Animals; Biological Transport; Fatty Acids; In Vitro Techniques; Lauric Acids; Male; Membranes; Myristic Acid; Myristic Acids; Propylene Glycol; Propylene Glycols; Rats; Rats, Wistar; Skin Absorption; Solubility; Stearic Acids; Thiamine