Stability study of drug-loaded proteinoid microsphere formulations during freeze-drying

Area of Science:

• Biomaterials Science
• Pharmaceutical Technology
• Drug Delivery Systems

Background:

• Proteinoid microspheres offer potential for drug delivery.
• Freeze-drying (lyophilization) is crucial for long-term storage and transport of sensitive formulations.
• Optimizing lyophilization is essential to maintain the structural integrity and drug loading of microspheres.

Purpose of the Study:

• To develop an optimized freeze-drying process for drug-loaded proteinoid microspheres.
• To investigate factors affecting microsphere integrity during lyophilization.
• To establish stable, long-term storage conditions for heparin-loaded proteinoid microspheres.

Main Methods:

• Investigated the effect of freezing temperature, cryoprotectants (trehalose, lactose), and formulation on microsphere stability.
• Determined optimal cryoprotectant concentrations (5% w/v).
• Evaluated microsphere integrity post-lyophilization and assessed stability over three months.

Main Results:

• Freezing at or below -70°C minimized microsphere damage.
• Addition of trehalose or lactose as cryoprotectants significantly enhanced microsphere stability.
• The optimized lyophilization process resulted in intact microspheres with at least three months of stability.

Conclusions:

• An optimized lyophilization protocol was successfully developed for heparin-loaded proteinoid microspheres.
• The study demonstrates the feasibility of freeze-drying proteinoid microspheres for improved storage and handling.
• The developed method ensures the stability and integrity of microspheres for pharmaceutical applications.