MPEG-PCL Copolymeric Micelles for Encapsulation of Azithromycin
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Anionic Polymerization of an Amphiphilic Copolymer for Preparation of Block Copolymer Micelles Stabilized by π-π Stacking Interactions
Published on: October 10, 2016
Wenxiu Wei1, Shida Li1, Hongmei Xu1
1School of Biological Science and Technology, University of Jinan, No. 336 West Road of Nanxinzhuang, Jinan, 250022, Shandong, People's Republic of China.
Abstract:
Macrolide antibiotics are lipophilic drugs with some limitations including low solubility, limited cellular permeation, patients discomfort, etc. With amphiphilic methoxy poly(ethylene glycol)-b-poly(ε-caprolactone) (MPEG-PCL) copolymer and azithromycin (AZT) as drug carrier and model drug, AZT-loaded micelles were prepared via thin-membrane hydration method in order to overcome these limitations. Encapsulation efficiency of AZT-loaded micelles was 94.40% with good storage stability for 28 days, and AZT's water solubility was enhanced to 944 μg/mL. Fourier transform infrared spectrum and x-ray diffraction analysis indicated that AZT was enveloped into the micelles in amorphous form due to its interaction with the copolymer. AZT's in vitro release from the AZT-loaded micelles demonstrated a slow and continuous behavior when compared with raw AZT. The release dynamics was accorded with Weibull equation, meaning that release amount of AZT lowered with time and was proportional to remaining amount of drug in the AZT-loaded micelles. Korsmeyer-Peppas fitting result suggested that drug release process was a classical Fickian diffusion-controlled manner. With Staphylococcus aureus as bacterial strain, antibacterial activity of the AZT-loaded micelles displayed was comparable with raw AZT. In conclusion, MPEG-PCL should be a promising carrier for macrolide antibiotic delivery in treatment of bacterial infections.
Insights
Methoxy poly(ethylene glycol)-b-poly(ε-caprolactone) (MPEG-PCL) micelles effectively encapsulate azithromycin (AZT), enhancing its solubility and stability. These novel drug delivery systems show comparable antibacterial activity to raw AZT, offering a promising approach for macrolide antibiotic delivery.
Area of Science:
- Materials Science
- Pharmaceutical Sciences
- Nanotechnology
Background:
- Macrolide antibiotics possess limitations such as poor solubility and cellular permeation.
- Developing advanced drug delivery systems is crucial to overcome these challenges.
- Methoxy poly(ethylene glycol)-b-poly(ε-caprolactone) (MPEG-PCL) is an amphiphilic copolymer with potential for drug encapsulation.
Purpose of the Study:
- To prepare and characterize azithromycin (AZT)-loaded micelles using MPEG-PCL copolymer.
- To evaluate the solubility enhancement, stability, and drug release profile of AZT-loaded micelles.
- To assess the antibacterial activity of the developed micellar formulation.
Main Methods:
- Micelles were prepared using the thin-membrane hydration method with MPEG-PCL and AZT.
- Encapsulation efficiency, solubility, and storage stability were determined.
- Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), in vitro release studies, and antibacterial assays were performed.
Main Results:
- High encapsulation efficiency (94.40%) and enhanced AZT water solubility (944 μg/mL) were achieved.
- Micelles exhibited good storage stability for 28 days.
- In vitro release studies indicated sustained drug release following Fickian diffusion, and antibacterial activity against Staphylococcus aureus was comparable to raw AZT.
Conclusions:
- MPEG-PCL copolymer effectively forms micelles for AZT delivery, overcoming solubility and permeation limitations.
- The developed AZT-loaded micelles demonstrate favorable stability, sustained release, and potent antibacterial efficacy.
- MPEG-PCL represents a promising carrier for macrolide antibiotic delivery in treating bacterial infections.
