Amorphous solubility advantage: Theoretical considerations, experimental methods, and contemporary relevance

Area of Science:

• Pharmaceutical Sciences
• Physical Chemistry
• Drug Delivery

Background:

• The concept of amorphous solubility advantage was first questioned 25 years ago.
• Significant advances in theoretical understanding and experimental methods have improved the determination of amorphous solubility.
• Amorphous solubility is now defined by phase separation into a drug-rich phase in metastable equilibrium with an aqueous phase.

Purpose of the Study:

• To review the concept of amorphous solubility advantage.
• To discuss theoretical considerations and experimental methods for measuring amorphous solubility.
• To explore the contribution of supersaturation and amorphous solubility to drug absorption.

Main Methods:

• Review of theoretical frameworks for amorphous solubility.
• Discussion of experimental techniques for amorphous solubility determination.
• Analysis of drug absorption from supersaturating formulations.

Main Results:

• Amorphous solubility represents a metastable equilibrium concentration, crucial for supersaturating formulations.
• Accurate measurement of amorphous solubility is now feasible due to theoretical and experimental advancements.
• Understanding amorphous solubility is vital for optimizing drug absorption, particularly for poorly water-soluble drugs.

Conclusions:

• Leveraging amorphous solubility principles can enhance the development of effective drug delivery strategies.
• Improved understanding of amorphous solubility leads to better therapeutic outcomes for poorly water-soluble drugs.
• Amorphous solubility is a critical parameter for absorption from supersaturating drug formulations.