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Inclusion Complex between Local Anesthetic/2-hydroxypropyl-β-cyclodextrin in Stealth Liposome
Gredson Keiff Souza1, André Gallo2, Luiza Hauser Novicki2
1Chemistry Institute, State University of Campinas, UNICAMP, Rua Josué de Castro Cidade Universitária, Campinas CEP 13083-970, Brazil.
Molecules (Basel, Switzerland)
|July 9, 2022
Summary
This study investigated supramolecular interactions between local anesthetics (butamben and ropivacaine) complexed with HP-βCD within Stealth liposomes. Nuclear magnetic resonance confirmed strong interactions and successful encapsulation, advancing drug delivery system knowledge.
Area of Science:
- Pharmaceutical Sciences
- Supramolecular Chemistry
- Drug Delivery Systems
Background:
- Drug delivery systems offer reduced toxicity and increased drug availability.
- Stealth liposomes (SL) are advanced carriers, but the behavior of local anesthetics (LAs) within them is underexplored.
- Butamben (BTB) and ropivacaine (RVC) are LAs with known interactions in conventional liposomes.
Purpose of the Study:
- To investigate supramolecular interactions between LAs (BTB, RVC) and 2-hydroxypropyl-β-cyclodextrin (HP-βCD).
- To confirm the encapsulation of these complexes within Stealth liposomes (SL).
- To characterize the behavior of BTB and RVC in SL drug delivery systems.
Main Methods:
- Proton nuclear magnetic resonance (¹H-NMR) spectroscopy, including Diffusion Ordered Spectroscopy (DOSY) and Saturation Transfer Difference (STD) NMR.
- Analysis of diffusion coefficients to quantify complex formation.
- Magnetization transfer analysis to confirm encapsulation within liposomes.
Main Results:
- ¹H-NMR displacements indicated complex formation between LAs and HP-βCD.
- Diffusion coefficients significantly decreased upon complexation, confirming strong BTB-HP-βCD interaction (98.3% molar fraction, Ka = 72.279 L/mol).
- STD-NMR confirmed the successful encapsulation of BTB/HP-βCD and RVC/HP-βCD complexes within SL vesicles.
Conclusions:
- HP-βCD effectively complexes with BTB and RVC, forming stable supramolecular structures.
- Stealth liposomes successfully encapsulate these LA-HP-βCD complexes, demonstrating their potential as advanced drug carriers.
- This study provides crucial insights into LA behavior within SL, paving the way for optimized drug delivery strategies.
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