Particle Metrology Approach to Understanding How Storage Conditions Affect Long-Term Liposome Stability

Area of Science:

• Biomedical Engineering
• Materials Science
• Pharmaceutical Sciences

Background:

• Lipid nanoparticles (LNPs) are versatile nanomaterials for medical drug delivery.
• Liposomes, a type of LNP, are used therapeutically, carrying genetic materials or pharmaceuticals.
• Understanding LNP long-term stability is critical for predicting shelf-life and storage conditions.

Purpose of the Study:

• To investigate factors influencing the long-term stability of liposomes.
• To determine the impact of lipid composition, buffer conditions (pH/composition), and storage temperature on liposome stability.
• To inform the development of NIST liposome-based reference materials.

Main Methods:

• A one-year stability study of liposomes in aqueous solution (no freezing).
• Evaluation of particle size and number concentration over time.
• Analysis of stability as a function of varying lipid composition, buffer parameters, and storage temperatures.

Main Results:

• Lipid composition was identified as the most critical factor affecting liposome stability.
• Storage temperature and buffer pH/composition had a lesser, though still notable, effect on stability.
• Particle size and number concentration changes were key indicators of stability.

Conclusions:

• Lipid composition is paramount for ensuring liposome stability and effective shelf-life.
• Optimal formulation and storage requirements can be better defined based on these findings.
• This research contributes to the understanding of long-term storage challenges for soft particles in biopharmaceuticals.