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Lipolysis and structure controlled drug release from reversed hexagonal mesophase
Nissim Garti1, Geut Hoshen, Abraham Aserin
1The Ratner Chair in Chemistry, Casali Institute of Applied Chemistry, The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel. garti@vms.huji.ac.il
Colloids and Surfaces. B, Biointerfaces
|February 21, 2012
Summary
This study shows how lipase enzyme can break down a hexagonal mesophase (H(II)) drug delivery system. This breakdown enhances drug release, offering a new method for controlled pharmaceutical delivery.
Area of Science:
- Materials Science
- Biotechnology
- Pharmaceutical Sciences
Background:
- Ternary reversed hexagonal mesophases (H(II)) are investigated for drug delivery.
- Lipase enzymes can modify lipid-based systems.
Purpose of the Study:
- To investigate the use of Thermomyces lanuginosa lipase within an H(II) mesophase for modulated drug delivery.
- To understand how lipolysis affects the H(II) structure and drug release kinetics.
Main Methods:
- Solubilization of lipase into a glycerol monooleate, tricaprylin, and water H(II) system.
- Monitoring structural changes of the mesophase during lipolysis using lattice parameter measurements.
- Quantifying the release of a model drug (sodium diclofenac) over time.
Main Results:
- Lipolysis initially preserved H(II) symmetry for ~200 min while hydrolyzing 40-60% of lipids, causing cylinder shrinking.
- A second lipolysis stage led to faster H(II) disintegration and significantly enhanced drug release.
- The H(II) mesophase fully disintegrated into immiscible phases after ~15 h.
- Drug release followed two-step Higuchi kinetics.
Conclusions:
- Lipase-mediated lipolysis effectively modulates the structural integrity of H(II) mesophases.
- This controlled degradation enhances the release rate of encapsulated drugs.
- The system demonstrates potential for lipolysis rate-controlled drug delivery applications.
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