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Preparation of Co-Amorphous Systems by Freeze-Drying
Melvin Wostry1, Hanna Plappert1, Holger Grohganz1
1Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark.
Pharmaceutics
|October 3, 2020
Summary
Freeze-drying effectively produced co-amorphous drug formulations using naproxen and amino acids. Surfactants influenced solid-state properties, with some systems showing stability issues upon storage.
Area of Science:
- Pharmaceutical Technology
- Materials Science
- Physical Chemistry
Background:
- Poorly water-soluble drugs often exhibit low bioavailability.
- Co-amorphous systems can enhance drug solubility and dissolution.
- Freeze-drying is a potential method for creating stable amorphous formulations.
Purpose of the Study:
- To evaluate freeze-drying as a production technique for naproxen co-amorphous systems.
- To investigate the role of surfactants in improving naproxen solubility and formulation.
- To assess the impact of surfactant type, concentration, and solid content on the final product.
Main Methods:
- Co-amorphous systems of naproxen with arginine and lysine were prepared via freeze-drying.
- Five surfactants (sodium dodecyl sulfate, pluronic F-127, polyoxyethylene (40) stearate, tween 20, TPGS 1000) were tested.
- Solid-state characterization using X-ray powder diffraction (XRPD) and differential scanning calorimetry (DSC).
Main Results:
- Most systems formed one-phase co-amorphous solids.
- Higher surfactant concentrations sometimes led to observable surfactant reflections in XRPD.
- Some formulations exhibited crystallization of naproxen or amino acids during storage.
Conclusions:
- Freeze-drying is a viable method for producing co-amorphous drug-amino acid formulations.
- Surfactant selection and concentration are critical for successful formulation.
- Long-term stability requires careful consideration of formulation components.
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