Functionality-type and chemical-composition separation of poly(lactide-co-glycolide) using gradient elution...

Area of Science:

• Polymer Chemistry
• Materials Science
• Analytical Chemistry

Background:

• End groups of poly(Lactide-co-glycolide) (PLGA) significantly influence polymer properties for drug delivery.
• Existing methods for analyzing PLGA end groups have limitations in molecular weight range or throughput.
• Understanding end-group functionality is crucial for predicting degradation and encapsulation efficiency.

Purpose of the Study:

• To develop a novel, high-throughput method for analyzing PLGA end groups.
• To characterize functionality type distribution (FTD) and chemical composition distribution (CCD) in PLGA polymers.
• To enable simultaneous separation of Lactic acid (LA)/Glycolic acid (GA) ratios.

Main Methods:

• Normal-phase liquid chromatography (LC) utilizing a cross-linked diol column.
• A ternary gradient elution system with Hexane, Ethyl Acetate, and Tetrahydrofuran.
• Separation of mono-ester and di-acid terminated PLGA, and ester-terminated PLGA with varying LA/GA ratios.

Main Results:

• The LC method successfully resolved FTD and partially CCD in commercial PLGA.
• Separation was achieved for PLGA polymers up to 183.0 kDa molecular weight.
• Simultaneous separation of different Lactic acid (LA)/Glycolic acid (GA) ratios was demonstrated.

Conclusions:

• The developed LC method offers a significant advancement for PLGA characterization.
• This technique facilitates a deeper understanding of the correlation between PLGA's FTD, CCD, and physical properties.
• The method is suitable for product development and quality control of PLGA in drug delivery systems.