Stability Studies of the Vaccine Adjuvant U-Omp19

April 1, 2021

Title

Stability Studies of the Vaccine Adjuvant U-Omp19

Author

M. Laura Darriba, María L. Cerutti, Laura Bruno, Juliana Cassataro, Karina A. Pasquevich

Year

2020

Journal

Journal of Pharmaceutical Sciences, RESEARCH ARTICLE DRUG DISCOVERY-DEVELOPMENT INTERFACE| VOLUME 110, ISSUE 2, P707-718, FEBRUARY 01, 2021

Abstract

Unlipidated outer membrane protein 19 (U-Omp19) is a novel mucosal adjuvant in preclinical development to be used in vaccine formulations. U-Omp19 holds two main properties, it is capable of inhibiting gastrointestinal and lysosomal peptidases, increasing the amount of co-administered antigen that reaches the immune inductive sites and its half-life inside cells, and it is able to stimulate antigen presenting cells in vivo. These activities enable U-Omp19 to enhance the adaptive immune response to co-administrated antigens.
To characterize the stability of U-Omp19 we have performed an extensive analysis of its physicochemical and biological properties in a 3-year long-term stability study, and under potentially damaging freeze-thawing and lyophilization stress processes. Results revealed that U-Omp19 retains its full protease inhibitor activity, its monomeric state and its secondary structure even when stored in solution for 36 months or after multiple freeze-thawing cycles. Non-enzymatic hydrolysis resulted the major degradation pathway for storage in solution at 4 °C or room temperature which can be abrogated by lyophilization yet increasing protein tendency to form aggregates.
This information will play a key role in the development of a stable formulation of U-Omp19, allowing an extended shelf-life during manufacturing, storage, and shipping of a future vaccine containing this pioneering adjuvant.

Instrument

J-1500

Keywords

Vaccine adjuvants, Stability, Analytical biochemistry, Protein formulation, Protein aggregation, Preformulation, Circular dichroism, Light scattering (dynamic), Lyophilization, Mucosal immunization, Oral drug delivery, Mucosal vaccination, Protease, Physicochemical properties