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Characteristics of Precipitation-formed Polyethylene Glycol Microgels Are Controlled by Molecular Weight of Reactants
Published on: December 23, 2013
Modification of crystallization behavior in drug/polyethylene glycol solid dispersions
Qing Zhu1, Michael T Harris, Lynne S Taylor
1School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States.
Molecular Pharmaceutics
|February 4, 2012
Summary
Polyethylene glycol (PEG) can alter active pharmaceutical ingredient (API) crystallization in solid dispersions. Depending on the API, PEG may delay, promote, or not affect API crystallization, impacting drug product stability.
Area of Science:
- Pharmaceutical Sciences
- Materials Science
- Physical Chemistry
Background:
- Solid dispersions are crucial for improving drug solubility and bioavailability.
- Understanding crystallization kinetics is vital for ensuring the stability and efficacy of solid dispersions.
- Polyethylene glycol (PEG) is a common excipient used in solid dispersions.
Purpose of the Study:
- To investigate the crystallization kinetics of various active pharmaceutical ingredient/polyethylene glycol (API/PEG) solid dispersions.
- To determine how different APIs and PEG interact to influence crystallization behavior.
- To assess the impact of PEG on the induction time and rate of API crystallization.
Main Methods:
- Wide-angle X-ray diffraction (WAXD) was used to analyze crystalline structures.
- Raman spectroscopy was employed to study molecular interactions and phase behavior.
- Solid dispersions of various APIs (benzocaine, haloperidol, ibuprofen, fenofibrate) with PEG were prepared and analyzed.
Main Results:
- PEG significantly decreased the crystallization rate of benzocaine (BZC) but did not affect haloperidol (HLP) crystallization.
- PEG decreased the induction time for ibuprofen (IBP) and fenofibrate (FNB) crystallization, potentially acting as a nucleation site.
- The crystallization behavior of PEG itself was also influenced by the presence of different APIs.
Conclusions:
- PEG's effect on API crystallization kinetics is API-dependent, ranging from delay to promotion or no effect.
- Crystalline PEG can act as a heterogeneous nucleation site for certain APIs.
- Thorough investigation of crystallization behavior is necessary for developing stable API/PEG solid dispersions with consistent properties.
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