Efficient production of solid dispersions by spray drying solutions of high solid content using a 3-fluid nozzle

Area of Science:

• Pharmaceutical Technology
• Materials Science

Background:

• Improving the dissolution of lipophilic drugs is crucial for enhancing bioavailability.
• Solid dispersions are a promising strategy to overcome poor drug solubility.
• Spray drying is a widely used technique for producing solid dispersions.

Purpose of the Study:

• To assess the feasibility of 3-fluid nozzle spray drying for creating solid dispersions.
• To optimize the production of solid dispersions for improved drug dissolution behavior.
• To investigate the impact of various process parameters on the characteristics of solid dispersions.

Main Methods:

• Utilized a Design of Experiments (DOE) approach with 60 experimental runs.
• Produced solid dispersions using diazepam (lipophilic drug) and mannitol (hydrophilic matrix).
• Varied parameters including water/organic solvent ratio, liquid feed flow, solid content, airflow, and solvent type (ethanol, ethyl acetate).

Main Results:

• The water/organic solvent ratio was the primary factor influencing enhanced dissolution rates.
• Total solid content did not impact any measured responses, enabling high-concentration processing.
• Organic solvent choice (ethanol vs. ethyl acetate) did not affect outcomes, demonstrating method versatility.

Conclusions:

• 3-fluid nozzle spray drying is a feasible and versatile method for producing solid dispersions.
• Optimizing the water/organic solvent ratio is key to enhancing drug dissolution.
• The process allows for high-concentration solutions and flexibility in solvent selection.