TY - JOUR
T1 - Incomplete cocrystalization of ibuprofen and nicotinamide and its interplay with formation of ibuprofen dimer and/or nicotinamide dimer
T2 - A thermodynamic analysis based on DFT data
AU - Asgarpour Khansary, Milad
AU - Walker, Gavin
AU - Shirazian, Saeed
N1 - Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2020/12/15
Y1 - 2020/12/15
N2 - Cocrystallization of ibuprofen and nicotinamide in hot melt extrusion process has been subject of many studies addressing low ibuprofen bioavailability. However, it is observed that the process of cocrystal formation of ibuprofen and nicotinamide might be incomplete. We hypothesized that formation of dimers of ibuprofen–ibuprofen or dimers nicotinamide– nicotinamide might be the cause of such poor cocrystalization process by altering the phase behaviour of the mixture. This paper addresses the molecular thermodynamics of mixtures of ibuprofen and nicotinamide, with special focus on the possibility of formation of these dimers and their corresponding interplay with mixture phase behaviour. For this purpose, density functional theory calculations are used to calculate electron donor-acceptor sizes on each molecule and accordingly possible dimers of each molecule are analysed. The free energies and phase diagram are determined for (1) when a dimer is formed or (2) no dimer is formed, over a wide operating temperature range of 273.15 K–390 K. The binding and solvation energies are calculated to identify/rank dimers. Calculations showed that formation of dimers requires an energy input which can be accessible noting to the external heating in hot melt extrusion process. The calculated solvation energies of the dimers suggest that addition of liquid binder (water) can mitigate the risk of dimer formations. Addition of proper binder/excipient is an easy route to compensate such dimer formation and to engineer ibuprofen and nicotinamide cocrystallization behaviour.
AB - Cocrystallization of ibuprofen and nicotinamide in hot melt extrusion process has been subject of many studies addressing low ibuprofen bioavailability. However, it is observed that the process of cocrystal formation of ibuprofen and nicotinamide might be incomplete. We hypothesized that formation of dimers of ibuprofen–ibuprofen or dimers nicotinamide– nicotinamide might be the cause of such poor cocrystalization process by altering the phase behaviour of the mixture. This paper addresses the molecular thermodynamics of mixtures of ibuprofen and nicotinamide, with special focus on the possibility of formation of these dimers and their corresponding interplay with mixture phase behaviour. For this purpose, density functional theory calculations are used to calculate electron donor-acceptor sizes on each molecule and accordingly possible dimers of each molecule are analysed. The free energies and phase diagram are determined for (1) when a dimer is formed or (2) no dimer is formed, over a wide operating temperature range of 273.15 K–390 K. The binding and solvation energies are calculated to identify/rank dimers. Calculations showed that formation of dimers requires an energy input which can be accessible noting to the external heating in hot melt extrusion process. The calculated solvation energies of the dimers suggest that addition of liquid binder (water) can mitigate the risk of dimer formations. Addition of proper binder/excipient is an easy route to compensate such dimer formation and to engineer ibuprofen and nicotinamide cocrystallization behaviour.
KW - Dimer formation
KW - Molecular interactions
KW - Pharmaceutical
KW - Phase behaviour
KW - Twin-screw granulator
UR - http://www.scopus.com/inward/record.url?scp=85093680599&partnerID=8YFLogxK
U2 - 10.1016/j.ijpharm.2020.119992
DO - 10.1016/j.ijpharm.2020.119992
M3 - Article
C2 - 33091551
AN - SCOPUS:85093680599
SN - 0378-5173
VL - 591
SP - 119992
JO - International Journal of Pharmaceutics
JF - International Journal of Pharmaceutics
M1 - 119992
ER -