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.
Percutaneous absorption of thiamine disulfide, (TDS), a lipophilic derivative of thiamine, from a mixture of propylene glycol (PG) and fatty acid (FA) or its analog through rat skin was tested in vitro. Lauric acid (12:0) enhanced the absorption depending on its concentration in PG and showed a maximal enhancement at 10% w/w. At 10% w/v, lauryl alcohol also enhanced the absorption, but less than 12:0, which lauric acid methyl ester suppressed the absorption. The flux of TDS did not depend on the solubility of TDS in the vehicle, but on the permeability coefficient. From these results, it is suggested that FA increases the permeability coefficient not only because FA increases TDS diffusion by disrupting lipid packing in the stratum corneum but also, FA increases TDS partition to lipid phase by interacting with TDS.
The formation of complexes between thiamine disulfide (TDS) orO‐acetyl thiamine disulfide (O‐acetyl TDS) and fatty acid or fatty acid methyl ester in methanol has been studied by fluorescence quenching and13C NMR relaxation (T1) measurements. The association constants (K‐values) of TDS andO‐acetyl TDS with fatty acids (from 11∶0 to 18∶0, and 18∶1, 18∶2, 18∶3 and 20∶4) and fatty acid methyl esters have been determined. These values do not depend on either the number of carbon atoms or the degree of unsaturation of the fatty acid. The K‐values of TDS andO‐acetyl TDS with fatty acid were 7.8 M−1 and 5.1 M−1, respectively. The K‐values of TDS andO‐acetyl TDS with fatty acid methyl ester were very small. These results show that the‐OH moiety in TDS and the‐COOH moiety in the fatty acid are necessary for formation of the complex
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.