Thermal stabilization of biologics inside glass vials using light-assisted drying (LAD)

Abstract

Light-assisted drying (LAD) uses near-infrared (1064 nm) laser light to selectively heat water, quickly dehydrating samples and forming an amorphous trehalose preservation matrix for biologics that can be stored at ambient temperatures. In this study, LAD is used to create preservation matrices inside glass vials used in industry. Sample volumes of 0.25 and 0.50 mL containing the model protein lysozyme were LAD processed. After LAD processing, samples were stored for one month at 4 °C or 20 °C. Thermal histories and transmitted laser power were monitored throughout processing to determine optimal drying times. The trehalose matrix was characterized using polarized light imaging to detect crystallization during storage. Karl Fischer titration was used to measure the water content of samples and differential scanning calorimetry was used to assess protein structure. LAD-processed samples had low water content (2%), were stable against crystallization and the protein structure was unaltered.