Neeraj Rai1, Paroma Chakravarty2, Raj Suryanarayanan2, and J. I. Siepmann1. (1) University of Minnesota, Department of Chemistry, Minneapolis, MN 55455-0431, (2) Department of Pharmaceutics, University of Minnesota, Minneapolis, MN 55455
Monte Carlo simulations in isotension-isothermal and Gibbs ensemble are carried out to investigate the stability and sorption behavior of the nonstoichiometric hydrate (NSH), isomorphic desolvate (ID), and hemihydrate (HH) of thiamine hydrochloride at different temperatures and relative humidities. The TraPPE and TIP4P force fields are used to model thiamine hydrochloride and water, respectively. The simulations provide molecular-level understanding on the different sorption behavior of these pharmaceutical polymorphs.