1 research outputs found
NaproxenâNicotinamide Cocrystals: Racemic and Conglomerate Structures Generated by CO<sub>2</sub> Antisolvent Crystallization
Cocrystallization of naproxen racemic
mixture and nicotinamide
was investigated in this work, using compressed CO<sub>2</sub> as
antisolvent. A novel racemic cocrystal structure containing both enantiomers
of naproxen linked to nicotinamide has been produced thanks to the
CO<sub>2</sub> antisolvent batch crystallization process. The structure
of the molecular complex and its intermolecular interactions were
investigated by single-crystal X-ray diffraction and attenuated total
reflectance Fourier transform infrared spectroscopy. The antisolvent
feed rate was found to have a direct influence on the cocrystallization
outcome. The racemic cocrystal was obtained at slow and moderate CO<sub>2</sub> feed rate, while very fast introduction of CO<sub>2</sub> resulted in the formation of a mixture of chiral cocrystals (conglomerate).
Cross-seedings, thermal analysis, and temperature-resolved X-ray powder
diffraction were used to probe the relationship between the different
phases. In addition, all powders produced with CO<sub>2</sub> technology
were obtained as cocrystal-pure, without significant excess of naproxen
or nicotinamide homocrystals