Modification of Drug Crystallization by Cyclodextrins in Pre-formulation Study.

Area of Science:

• Pharmaceutical Science
• Materials Science
• Physical Chemistry

Background:

• Controlling drug crystallization is crucial in pre-formulation studies.
• Advanced additives are increasingly used to manage drug crystallization behavior.
• Hydrophilic cyclodextrins (CDs) are emerging as effective additives for this purpose.

Purpose of the Study:

• To review the application of hydrophilic cyclodextrins (CDs) in controlling drug crystallization.
• To explore the mechanisms by which CDs influence crystallization in solution and solid states.
• To highlight the role of CDs in crystal engineering and amorphous formulation.

Main Methods:

• Host-guest interactions between CDs and drug molecules.
• Selective suppression of crystallization pathways.
• Modification of crystal morphology (habit) through controlled growth.
• Preparation of stable amorphous drug/CDs complexes.

Main Results:

• CDs, through host-guest interactions, can suppress solution-mediated transitions, leading to selective precipitation of metastable drug forms.
• CDs facilitate crystal engineering by altering crystallization pathways, enabling the discovery of new polymorphs.
• CDs can modify crystal habit by selectively inhibiting growth in specific directions.
• Stable amorphous drug/CDs complexes were prepared using specific CDs, even under humid conditions.

Conclusions:

• Hydrophilic cyclodextrins are versatile additives for controlling drug crystallization processes.
• CDs offer opportunities for polymorph discovery and crystal habit modification.
• CDs are valuable in developing stable amorphous drug formulations.