Control and Prediction of the Organic Solid State

• Studies of 5-fluorouracil, a common pharmaceutical (anti-cancer properties) with only one known polymorph (Form I)
• Simulation studies (MD using DL_POLY3) in conjunction with experimental work and crystal structure prediction in the search for new stable polymorphs.
• Crystallization and lattice statics studies found one new polymorph - (Form II) in which each molecule forms two dimer hydrogen bond pairs in a ribbon motif . predicted to be thermodynamically more stable.
• MD studies of dissolution of form I in water on HPCx (cluster of 16 fluorouracil molecules with 1938 water molecules) provides mechanism for crystal Form I to grow.

Crystal structure of 5-fluorouracil as crystallized from water.
(Form I)