Strategies to improve the stability of amorphous solid dispersions in view of the hot melt extrusion (HME) method

Oral administration of drugs is preferred over other routes for several reasons: it is non-invasive, easy to administer, and easy to store. However, drug formulation for oral administration is often hindered by the drug's poor solubility, which limits its bioavailability and reduces its commercial value. As a solution, amorphous solid dispersion (ASD) was introduced as a drug formulation method that improves drug solubility by changing the molecular structure of the drugs from crystalline to amorphous. The hot melt extrusion (HME) method is emerging in the pharmaceutical industry as an alternative to manufacture ASD. However, despite solving solubility issues, ASD also exposes the drug to a high risk of crystallisation, either during processing or storage. Formulating a successful oral administration drug using ASD requires optimisation of the formulation, polymers, and HME manufacturing processes applied. This review presents some important considerations in ASD formulation, including strategies to improve the stability of the final product using HME to allow more new drugs to be formulated using this method.

Automated summary

Oral administration of drugs is preferred for being non-invasive, easy to administer, and easy to store. However, the poor solubility of drugs in oral formulations limits their effectiveness and commercial value. Amorphous solid dispersion (ASD), a method that changes the molecular structure of drugs to improve solubility, is being used with the emerging hot melt extrusion (HME) method in the pharmaceutical industry. Despite solving solubility issues, ASD also poses a risk of crystallization, requiring optimization in formulation, polymers, and HME manufacturing processes.