Hot melt extrusion (HME) technology is widely used in the development of amorphous solid dispersions; polymers play essential roles in the preparation of polymer-drug amorphous solid dispersions. This paper explores the criteria for selecting suitable polymers for the preparation of amorphous solid dispersions using hot melt extrusion.

In the previous article, we explored common techniques for characterizing ASD. After characterization, it is essential to evaluate ASD’s solubility, dissolution rate, and stability to determine its suitability for further development. This section will focus on the comprehensive evaluation of ASD.

The characterization of ASD commonly employs various analytical techniques, including XRPD, DSC, PLM, SEM, IR, RM, and ssNMR. These methods provide essential insights into the physical and chemical properties of ASD, facilitating an understanding of its behavior under various conditions.

In the development of a robust and effective Amorphous Solid Dispersion (ASD) formulation, it is imperative to rigorously evaluate several key factors, encompassing drug-polymer miscibility, drug solubility in the polymer, drug-polymer interactions, manufacturing processes, and storage conditions.

Spray drying techniques are extensively employed in developing formulations for drugs with low solubility, largely due to their well-established scalability from small-scale experiments to large-scale commercial production, aligning with Good Manufacturing Practice (GMP) standards.

HME is recognized as an optimal and efficient technique for manufacturing ASD, characterized by its continuous processing, increased production efficiency, reduced energy consumption, and environmental sustainability, particularly suitable for the preparation of formulations for drugs with poor solubility.

Depending on the approach used to disturb the crystalline lattice, ASD preparation methods can be broadly classified into two categories: solvent-based methods and melting or fusion methods.

ASD, a formulation technology, operates on the fundamental principle of blending drug molecules with suitable polymer-carriers. This process ensures the uniform dispersion of drug molecules within the polymer matrix, resulting in the formation of an amorphous solid solution or suspension.

Various widely employed method for solubility enhancement, including salt formation, polymorphism, particle size reduction of active pharmaceutical ingredients (APIs), the preparation of amorphous solid dispersions (ASD), and the addition of cyclodextrins or surfactants.