(58h) Controlled Nano-Scale Polymorph Production of Alpha/Beta Glutaric Acid from Aqueous Solution Atomization/Evaporation

Glutaric acid is a water soluble and commonly used dicarboxylic acid. It exhibits dimorphism, which means that the molecule can form two different types of crystal structures. The two polymorphs of Glutaric Acid are known as the alpha and beta polymorphs. The alpha polymorph is in the meta-stable phase, meaning that it is less stable and after some time will revert back to the beta polymorph. The alpha polymorph is favored at higher temperatures and is more soluble than the beta phase, and has been produced under some very specific conditions. This is thought to have led to some variability with regard to the data collected in several experiments involving glutaric acid.

In this work, we investigated the formation of alpha glutaric acid polymorph in aerosols generated from an aqueous glutaric acid solution. We have experimented with solution concentration, solution flow rate into the atomizer, and drying rate of the atomized droplets. By manipulating the rate of water evaporation from aqueous solution droplets, we have manged to control which polymorph we produce - alpha, beta, or both at the same time. The formation of both polymorphs from an aqueous solution has never been documented before. Understanding the conditions that lead to the formation of the alpha polymorph will be valuable if this method can be used to produce more pharmaceutical-relevant products, particularly ones that are sensitive to heat or otherwise difficult to control.