Rapid Quantification and Validation of Lipid Concentrations within Liposomes

Area of Science:

• Vaccine Development
• Lipid Nanoparticle Technology
• Analytical Chemistry

Background:

• Lipid content in liposomal adjuvants is critical for subunit vaccine efficacy and stability.
• Accurate quantification of lipids is essential for reproducible vaccine formulation.
• Existing methods may require complex lipid extraction procedures.

Purpose of the Study:

• To develop and validate a rapid, simultaneous quantification method for lipids in liposomal adjuvants.
• To assess the applicability of the method across different liposomal manufacturing techniques.
• To establish the sensitivity and linearity of the developed analytical method.

Main Methods:

• High-performance liquid chromatography coupled with an evaporative light-scattering detector (HPLC-ELSD).
• Quantification of four key lipids: DMPC, cholesterol, DDA bromide, and TDB.
• Analysis of liposomes prepared using lipid film hydration, high shear mixing, and microfluidics.

Main Results:

• The HPLC-ELSD method demonstrated rapidity, high sensitivity, and excellent linearity (R² > 0.993) for all four lipids.
• Achieved low limits of detection and quantification for DMPC, cholesterol, DDA, and TDB.
• Successfully quantified lipids in liposomes produced by three distinct manufacturing methods without lipid extraction.

Conclusions:

• The developed HPLC-ELSD method is a rapid, sensitive, and effective tool for quantifying lipids in liposomal vaccine formulations.
• This method simplifies lipid analysis, eliminating the need for pre-extraction steps.
• It supports the quality control and development of liposomal adjuvants across various production techniques.