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Preparation and Characterization of Griseofulvin Solid Dispersions
Rajvi J Wani1, Puneet Sharma2, H Andy Zhong3
1College of Education and Human Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, USA.
Assay and Drug Development Technologies
|April 23, 2020
Summary
High crystallization tendency compounds like griseofulvin (GSV) require higher polymer concentrations for stable amorphous solid dispersions (SD). Polyvinylpyrrolidone K-90 showed effectiveness at a 1:1 ratio, unlike other polymers at lower concentrations.
Area of Science:
- Pharmaceutical Sciences
- Materials Science
- Drug Delivery
Background:
- Amorphous solid dispersions (SD) enhance solubility and bioavailability of poorly water-soluble drugs.
- The stability of amorphous forms is challenged by their tendency to crystallize, impacting drug efficacy.
- Griseofulvin (GSV) is a model compound with high crystallization tendency, making its SD stability a critical research area.
Purpose of the Study:
- To evaluate the stability of griseofulvin amorphous solid dispersions (SD) using various Food and Drug Administration-approved hydrophilic polymers.
- To determine the effectiveness of different drug-to-polymer ratios in inhibiting GSV crystallization.
- To investigate the role of polymer-drug interactions in stabilizing amorphous dispersions.
Main Methods:
- Preparation of physical mixtures (PM) and SD of GSV with polymers (PVP, HPMC, Eudragits, PEG) via solvent evaporation.
- Characterization using powder X-ray diffractometry (PXRD) and modulated differential scanning calorimetry (mDSC) to assess amorphous state and crystallization.
- Spectroscopic analysis (IR, Raman) and molecular modeling to explore drug-polymer interactions.
Main Results:
- Most tested polymers were ineffective at stabilizing amorphous GSV at low drug-to-polymer ratios (3:1, 1:1, 1:2 w/w).
- Polyvinylpyrrolidone K-90 (PVP K-90) demonstrated stabilization effectiveness at a 1:1 w/w ratio.
- Inconclusive peak shifts in IR and Raman spectra suggested limited direct molecular interactions between GSV and polymers.
Conclusions:
- Griseofulvin's inherent high crystallization tendency and limited hydrogen bonding capacity impede stable amorphous SD formation.
- Higher polymer concentrations are necessary to achieve long-term stability for amorphous solid dispersions of challenging compounds like GSV.
- The choice and concentration of polymer are critical factors for successful stabilization of amorphous solid dispersions.
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