Drug-polymer intermolecular interactions in hot-melt extruded solid dispersions

Area of Science:

• Pharmaceutical Sciences
• Materials Science
• Polymer Chemistry

Background:

• Solid dispersions enhance drug solubility and bioavailability.
• Hot-melt extrusion (HME) is a key technique for creating solid dispersions.
• Understanding drug-polymer interactions is crucial for formulation design.

Purpose of the Study:

• Investigate drug-polymer interactions in solid dispersions.
• Identify interaction types between cationic drugs and anionic polymers processed via HME.
• Characterize the influence of these interactions on formulation properties.

Main Methods:

• Hot-melt extrusion (HME) for processing drug-polymer systems.
• Physicochemical characterization of extrudates (morphology, drug state).
• Molecular modeling and X-ray photon spectroscopy (XPS) for interaction analysis.

Main Results:

• Confirmed intermolecular ionic interactions between drug amino groups and polymer carboxylic groups.
• Identified hydrogen bonding as a key interaction mechanism.
• Demonstrated that interaction magnitude correlates with drug-polymer miscibility.

Conclusions:

• HME effectively creates solid dispersions with significant drug-polymer interactions.
• Hydrogen bonding and ionic interactions are critical for stabilizing cationic drugs within anionic polymer matrices.
• Drug-polymer miscibility is directly influenced by the strength of these intermolecular forces.