Mechanistic In Situ and Ex Situ Studies of Phase Transformations in Molecular Co-Crystals.

Co-crystallisation is widely explored as a route to improve the physical properties of pharmaceutical active ingredients, but little is known about the fundamental mechanisms of the process. Herein, we apply a hyphenated differential scanning calorimetry-X-ray diffraction technique to mimic the commercial hot melt extrusion process, and explore the heat-induced synthesis of a series of new co-crystals containing isonicotinamide. These comprise a 1:1 co-crystal with 4-hydroxybenzoic acid, 2:1 and 1:2 systems with 4-hydroxyphenylacetic acid and a 1:1 crystal with 3,4-dihydroxyphenylactic acid.

Gaseous "nanoprobes" for detecting gas-trapping environments in macroscopic films of vapor-deposited amorphous ice.

Vapor-deposited amorphous ice, traditionally called amorphous solid water (ASW), is one of the most abundant materials in the universe and a prototypical material for studying physical vapor-deposition processes. Its complex nature arises from a strong tendency to form porous structures combined with complicated glass transition, relaxation, and desorption behavior. To gain further insights into the various gas-trapping environments that exist in ASW and hence its morphology, films in the 25-100 μm thickness range were codeposited with small amounts of gaseous "nanoprobes" including argon, methane, helium, and carbon dioxide.

Drug repurposing in neurological diseases: an integrated approach to reduce trial and error.

Identifying effective disease-modifying therapies for neurological diseases remains an important challenge in drug discovery and development. Drug repurposing attempts to determine new indications for pre-existing compounds and represents a major opportunity to address this clinically unmet need. It is potentially more cost-effective and time-efficient than de novo drug development and has yielded notable successes in neurological disorders.

Polymorphic Phase Transitions in Carbamazepine and 10,11-Dihydrocarbamazepine.

Temperature-induced phase transitions in carbamazepine (CBZ) and 10,11-dihydrocarbamazepine (DHC) were studied by simultaneous differential scanning calorimetry-X-ray diffraction in this work. The transitions generally involve a transitional melt phase which is quickly followed by recrystallisation. The expansions of the unit cell as a function of temperature could be quantified and allow us to determine a directional order of stability in relation to the lattice constants.