Vitamin B1 is one of the most essential nutrients in human bodies. Thiamine hydrochloride

a form of vitamin B1

has four solvates

hemihydrate (HH)

methanol solvates (MM)

nonstoichiometric hydrate (NSH)

and anhydrous form (AH). These four solvates have different stabilities because of different space structures. In that way

a stable solvate which has better properties of production

storage and transportation is investigated by drug industry. In this paper

X-ray diffraction and thermal analysis were measured and crystal form transformation experiments in methanol-water and methanol-ethyl acetate were investigated. It can be seen that hydrate hemihydrate is more stable because of hydrogen bonds. Moreover

molecular dynamics simulation by using BFDH and AE model of MM in methanol-ethyl acetate binary solvent mixtures was calculated. The result shows that BFDH model matches real crystal habit

which could guide industrial production.