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Updated: Jul 2, 2026
11:27
A Package of Established Analytical Tools to Investigate the Solid-State Alteration of Lipid-Based Excipients
Published on: August 9, 2022
Solid lipid extrudates as sustained-release matrices: the effect of surface structure on drug release properties
Claudia Reitz1, Clare Strachan, Peter Kleinebudde
1Institute of Pharmaceutics and Biopharmaceutics, Heinrich-Heine-University Duesseldorf, Germany.
Summary
Solid lipid extrusion creates sustained-release matrices where surface dissolution is slower than cut surfaces. Minimizing drug particle size and using intact extrudates reduces initial burst release.
Area of Science:
- Pharmaceutical Technology
- Materials Science
- Drug Delivery Systems
Background:
- Sustained-release formulations are crucial for controlled drug delivery.
- Lipid matrices offer potential for modulating drug release kinetics.
- Solid lipid extrusion is an emerging technique for preparing these matrices.
Purpose of the Study:
- To structurally characterize sustained-release lipid matrices prepared by solid lipid extrusion.
- To investigate differences in chemical and structural composition between the surface and core of extrudates.
- To correlate formulation and processing parameters with drug dissolution behavior.
Main Methods:
- Solid lipid extrusion technique for matrix preparation.
- Local analysis of extrudate surface and core.
- Solid-state analysis including Differential Scanning Calorimetry (DSC), Attenuated Total Reflectance Fourier-Transform Infrared Spectroscopy (ATR-FTIR), and Scanning Electron Microscopy (SEM).
Main Results:
- Dissolution from outer extrudate surfaces was slower than from cut surfaces.
- Higher burst effect observed from cross-sections due to increased drug exposure.
- Morphological differences, not chemical ones, explained surface vs. core variations.
- Glycerol trimyristate matrices showed slower release than glycerol palmitostearate matrices.
- Friction-induced temperature increase during extrusion likely caused surface differences.
Conclusions:
- Solid lipid extrusion produces lipid matrices with distinct surface and core properties.
- Morphological changes during extrusion influence drug dissolution.
- Optimizing drug particle size and maintaining extrudate integrity minimizes burst release, enhancing formulation performance.
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