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Updated: Mar 15, 2026
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PLGA Nanoparticles Formed by Single- or Double-emulsion with Vitamin E-TPGS
Published on: December 27, 2013
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Characterizing release mechanisms of leuprolide acetate-loaded PLGA microspheres for IVIVC development I: In vitro
Keiji Hirota1, Amy C Doty1, Rose Ackermann1
1Department of Pharmaceutical Sciences, The Biointerfaces Institute, University of Michigan, 2800 Plymouth Rd., Ann Arbor, MI 48109, USA.
Summary
Investigating incubation media effects on leuprolide-loaded PLGA microspheres revealed that acidic pH and plasticizers accelerate drug release. This understanding is key for predicting controlled-release drug efficacy.
Area of Science:
- Polymer Science
- Pharmaceutical Sciences
- Drug Delivery
Background:
- Controlled release microspheres are crucial for drug efficacy.
- Understanding in vitro release mechanisms is essential for quality control.
Purpose of the Study:
- To investigate the impact of incubation media on leuprolide release from PLGA microspheres.
- To elucidate the influence of pH, plasticization, and buffer type on accelerated release mechanisms.
Main Methods:
- Preparation of leuprolide-loaded PLGA microspheres using double emulsion-solvent evaporation or self-healing methods.
- Incubation of microspheres in various media (pH 5.5-7.4, with or without triethyl citrate) for up to 56 days.
- Analysis of drug release, polymer molecular weight, water uptake, mass loss, and dye diffusion.
Main Results:
- Acidic buffers and triethyl citrate accelerated PLGA degradation and drug release.
- Release mechanisms shifted from erosion to peptide desorption/pore breakage after 21 days.
- End-capped PLGA showed delayed release compared to acid-capped PLGA.
Conclusions:
- Incubation media significantly influence the in vitro release kinetics of leuprolide from PLGA microspheres.
- Data provides a baseline for in vitro-in vivo correlation development.
- Findings support rational design of controlled-release drug formulations.
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