Preventing the transition of the amorphous state into thermodynamically more stable forms is a major challenge. The problem is exacerbated with mixtures of drugs, which additionally have the possibility to demix in the solid state into their individual constituents.

 In trying to solve the stability challenge, polymers are usually employed to provide an amorphous matrix in which the drug can dissolve, whereby the viscosity of the matrix is usually high enough to prevent recrystallization on storage. However, high polymer loadings (e.g. 50-90%) are frequently used with other technologies limiting the usefulness of the approach.

The ASP Process (Atmospheric Supercritical Precipitation) is capable of producing stable amorphous solid-states of pure drugs and mixtures of drugs usually with a very high drug loading (e.g. > 90 %). Excipients such as polymers, antioxidants or pH-regulators can be added to provide an optimal matrix for the amorphous drug or drug mixture.

Drug/excipient mixtures are recovered as fine dry powder in the form of a molecular dispersion, providing intimate contact between the components thus generating a stable form even under accelerated stability conditions