Scanning Analysis of Sequential Semisolvent Vapor Impact To Study Naltrexone Release from Poly(lactide-co-glycolide)...

Area of Science:

• Materials Science
• Pharmaceutical Sciences
• Chemical Engineering

Background:

• Poly(lactide-co-glycolide) (PLGA) microparticles are crucial for long-acting injectable drug delivery.
• Advanced characterization techniques are needed to fully understand PLGA formulation behavior.
• Surface Analysis of Vapor Impact (SAVI) is a novel method for microparticle analysis.

Purpose of the Study:

• To apply the SAVI method to naltrexone-loaded PLGA microparticles, including a commercial product (Vivitrol).
• To investigate the microstructural changes and their impact on drug release mechanisms.
• To evaluate SAVI's utility in pharmaceutical research and development.

Main Methods:

• Sequential application of semisolvent vapors to PLGA microparticles.
• Morphological analysis using laser scanning confocal microscopy.
• Quantification of surface parameters (Sa, Sk, Sku, Vvv, Spd, Hm, Rs) and correlation with drug release.

Main Results:

• SAVI analysis identified naltrexone crystallization and PLGA chain degradation as key release mechanisms.
• Higher naltrexone crystal content correlated with prolonged drug release.
• SAVI data complemented findings from gel permeation chromatography, DSC, and in vitro release studies.

Conclusions:

• The SAVI method provides valuable insights into the microstructure of PLGA formulations.
• Naltrexone crystal formation is a critical factor influencing release kinetics.
• SAVI is a promising tool for research, product development, and quality control of microparticle drug delivery systems.