Combining X-ray and NMR Crystallography to Explore the Crystallographic Disorder in Salbutamol Oxalate.

Salbutamol is an active pharmaceutical ingredient commonly used to treat respiratory distress and is listed by the World Health Organization as an essential medicine. Here, we establish the crystal structure of its oxalate form, salbutamol oxalate, and explore the nature of its crystallographic disorder by combined X-ray crystallography and C cross-polarization (CP) magic-angle spinning (MAS) solid-state NMR. The *C-OH chiral center of salbutamol (note that the crystal structures are a racemic mixture of the two enantiomers of salbutamol) is disordered over two positions, and the -butyl group is rotating rapidly, as revealed by C solid-state NMR.

Concurrent Antisolvent Electrospraying: A Novel Continuous Crystallization Technique.

Pharmaceutical co-crystals (CCs) are multicomponent materials that enable the development of novel therapeutic products by enhancing the properties of active pharmaceutical ingredients, such as solubility, permeability and bioavailability. Currently, CCs are a commercial reality; nonetheless, their industrial production remains a challenge due to problems related to scale up, control and mode of preparation, which usually relies on batch production rather than continuous. This paper describes the implementation of a concurrent coaxial antisolvent electrospray (Co-E), as a new manufacturing technique, for the synthesis of CCs in a rapid, continuous and controlled manner.