Spray-Dried Paracetamol/Polyvinylpyrrolidone Amorphous Solid Dispersions: Part I-Stability of Powders and Tablets

The formulation of active pharmaceutical ingredients (APIs) in amorphous solid dispersions (ASDs) is a promising approach to improve the bioavailability of poorly soluble compounds. However, problems often arise in the production of tablets from ASDs regarding the compressibility and recrystallization of the API. In the present study, the preparation of spray-dried ASDs of paracetamol (PCM) and four different types of polyvinylpyrrolidone (PVP) and their further processing into tablets were investigated. The influence of PVP type on the glass transition temperature (T-g) and the physical stability of ASD powders were characterized by differential scanning calorimetry (DSC) and powder X-ray diffraction (XRD). ASD powders with 10 to 30% PCM were stable for at least 48 weeks. PCM contents of 40 to 50% led to recrystallization of the amorphous PCM within a few days or weeks. ASD with PVP/vinyl acetate (VA) copolymer (PVP/VA) was the most unstable and tended to recrystallize in PCM polymorphic form II. This formulation was therefore used for tablet studies. The influence of compression force on recrystallization, crushing strength, and drug release was investigated. Even high compression forces did not affect the stability of the ASD. However, the ASD tablets led to slow release of the API.

Automated summary

Formulating APIs in ASDs is a promising approach to improve bioavailability of poorly soluble compounds, but challenges such as compressibility and recrystallization may arise during tablet production. The study investigated the influence of different types of PVP on the stability of ASD powders, with varying PCM contents leading to recrystallization. PVP/VA copolymer was found to be the most unstable, resulting in slow drug release from the ASD tablets.