Creation of Long-Term Physical Stability of Amorphous Solid Dispersions N-Butyl-N-methyl-1-phenylpyrrolo[1,2-a]pyrazine-3-carboxamide, Resistant to Recrystallization Caused by Exposure to Moisture

Amorphous solid dispersion (ASD) technology is often used as a promising strategy to improve the solubility of active pharmaceutical ingredients (APIs). ASDs allow APIs to be dispersed at the molecular level in a polymer carrier, destroying the crystalline structure of the APIs and, thanks to the polymer, providing long-term supersaturation in solution. However, stability issues are an obstacle to the development of new medications with ASD. In addition to the molecular mobility at elevated temperatures leading to the crystallization of APIs, moisture affects the physical stability of ASD, leading to fractional separation and recrystallization. N-butyl-N-methyl-1-phenylpyrrolo[1,2-a]pyrazine-3-carboxamide (GML-3) is an original API with both anxiolytic and antidepressant activity, but its insolubility in water can negatively affect (influence) bioavailability. Our study aims to create ASD GML-3 with moisture-resistant polymers (Soluplus®, HPC) and assess the stability of the amorphous state of ASD after storage in high humidity conditions. As a result, HPC KlucelTM FX was revealed to be more stable than the brand, providing a high level of API release into the purified water environment and stability after 21 days (3 weeks) of storage in high humidity conditions.