Development and validation of a static multiple light scattering (SMLS) method for real-time colloidal stability...

Area of Science:

• Pharmaceutical Sciences
• Materials Science
• Biotechnology

Background:

• Nanoparticles offer significant therapeutic potential but require stable formulations for clinical success.
• Current methods like dynamic light scattering (DLS) have limitations in assessing real-time colloidal stability, especially for concentrated or polydisperse systems.
• Colloidal stability is critical for determining nanoparticle behavior, safety, and regulatory approval.

Purpose of the Study:

• To develop and validate a static multiple light scattering (SMLS)-based method for real-time, non-invasive assessment of nanoparticle colloidal stability.
• To compare the efficacy of SMLS against dynamic light scattering (DLS) for evaluating various nanoparticle formulations.
• To establish SMLS as a reliable tool for optimizing nanoparticle design and ensuring regulatory compliance.

Main Methods:

• Application of static multiple light scattering (SMLS) to assess colloidal stability of standardized particles and commercial nanoparticle formulations (liposomes, nanoparticles, micelles, nanoemulsions).
• Real-time monitoring of destabilization kinetics (aggregation, sedimentation, creaming) without sample dilution.
• Quantification of instability using the Turbiscan stability index (TSI) and correlation with particle size distribution.

Main Results:

• SMLS successfully captured real-time destabilization kinetics in concentrated nanoparticle formulations, outperforming DLS.
• DLS failed to accurately assess polydisperse systems due to its time-point sampling limitations.
• TSI values correlated with particle size distribution broadening, indicating SMLS's sensitivity to instability.
• Commercial formulations showed minimal variations in transmission/backscattering and low TSI values, indicating good stability via SMLS.

Conclusions:

• SMLS is a superior method for real-time, non-invasive assessment of nanoparticle colloidal stability compared to DLS.
• SMLS accurately reflects native-state nanoparticle behavior, even at high concentrations and for polydisperse systems.
• This validated SMLS method addresses a critical gap, facilitating nanoparticle optimization, FDA compliance, and clinical translation.