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Anionic Polymerization of an Amphiphilic Copolymer for Preparation of Block Copolymer Micelles Stabilized by π-π Stacking Interactions
Published on: October 10, 2016
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Improved dissolution of an enteric polymer and its amorphous solid dispersions by polymer salt formation
1Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, IN 47907, United States.
International Journal of Pharmaceutics
|June 6, 2022
Summary
Pre-ionizing weakly acidic polymers like hydroxypropyl methylcellulose phthalate (HP-50) into polymer salts significantly enhances dissolution rates for amorphous solid dispersions (ASDs). This strategy improves drug release, especially at higher drug loadings, addressing key challenges in ASD formulation development.
Area of Science:
- Pharmaceutical Sciences
- Materials Science
Background:
- Weakly acidic polymers are used in amorphous solid dispersions (ASDs) for solubility enhancement.
- Understanding polymer dissolution in ASDs, particularly with lipophilic drugs, is crucial for formulation design.
- Contemporary ASD challenges include achieving good drug release at higher drug loadings.
Purpose of the Study:
- To investigate the dissolution behavior of weakly acidic polymers in ASDs.
- To identify critical factors influencing polymer dissolution, focusing on ionization.
- To develop strategies for enhanced drug release from ASDs.
Main Methods:
- Hydroxypropyl methylcellulose phthalate (HP-50) was converted into polymer salts via neutralization.
- Surface-normalized dissolution studies were conducted at pH 6.8.
- Amorphous solid dispersions (ASDs) were formulated with miconazole using HP-50 and polymer salts.
- Drug release rates from ASDs were compared.
Main Results:
- Polymer salts exhibited approximately 3-fold faster release than HP-50 at pH 6.8.
- Polymer salt dissolution rate was independent of buffer capacity, unlike protonated HP-50.
- ASDs formulated with polymer salts showed 14 times faster drug release compared to HP-50 ASDs.
Conclusions:
- Polymer ionization is a critical factor in the dissolution of HP-50-based systems.
- Buffer capacity significantly impacts the dissolution of protonated polymers in ASDs.
- Pre-ionization via polymer salt formation is an effective strategy for improving ASD performance and drug release.
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