Sulbutiamine

Sulbutiamine (brand name: Arcalion) is a synthetic derivative of thiamine (vitamin B₁). As a dimer of two modified thiamine molecules, it is a lipophilic compound that crosses the blood–brain barrier more readily than thiamine and increases the levels of thiamine and thiamine phosphate esters in the brain. Sulbutiamine was discovered in Japan in an effort to develop more useful thiamine derivatives since it was hoped that increasing the lipophilicity of thiamine would result in better pharmacokinetic properties.