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Mechanism of Dissolution-Induced Nanoparticle Formation from a Copovidone-Based Amorphous Solid Dispersion.
Paul Harmon1, Kendra Galipeau1, Wei Xu2
1Analytical Sciences, Merck Research Laboratories, Merck & Co., Inc. , West Point, Pennsylvania 19486, United States.
Molecular Pharmaceutics
|March 29, 2016
Summary
Amorphous solid dispersions (ASDs) enhance drug solubility and dissolution. Surfactants prevent drug aggregation during ASD dissolution, enabling the formation of amorphous drug nanoparticles for improved bioavailability.
Area of Science:
- Pharmaceutical Sciences
- Materials Science
Background:
- Amorphous solid dispersions (ASDs) improve solubility and dissolution rates of poorly soluble drugs.
- ASD dissolution can generate amorphous drug nanoparticles, further enhancing bioavailability.
Purpose of the Study:
- To elucidate the mechanism of amorphous drug nanoparticle formation from ASDs.
- To investigate the role of surfactant (TPGS) in preventing drug aggregation during ASD dissolution.
Main Methods:
- Studied an ASD composed of copovidone, anacetrapib, and varying concentrations of TPGS.
- Analyzed nanoparticle formation during ASD dissolution using microscopy and dissolution testing.
Main Results:
- Nanoparticle formation originates from amorphous drug domain formation within the ASD particle.
- Copovidone dissolution drives amorphous drug domain formation.
- Surfactant (TPGS) prevents rapid local drug domain aggregation ('hydrophobic capture').
Conclusions:
- Surfactant enables amorphous drug domains to escape aggregation and form nanoparticles in solution.
- This clarifies the mechanism of surfactant-mediated nanoparticle formation in ASDs.
- Provides insights into optimizing ASD formulations for enhanced drug delivery.
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