Osmolyte-Based Formulations for Enhanced Thermal Stability of mRNA Drug Substance: A Systematic Screening and...

Area of Science:

• Biochemistry
• Molecular Biology
• Vaccine Technology

Background:

• Messenger RNA (mRNA) stability is paramount for the efficacy and shelf-life of mRNA-based vaccines.
• Ensuring mRNA integrity under various storage and thermal conditions is a key challenge in vaccine development.

Purpose of the Study:

• To systematically investigate the impact of various osmolytes and their combinations on mRNA integrity.
• To evaluate the protective effects of osmolytes during long-term storage and thermal stress.

Main Methods:

• Eleven osmolytes (amino acids, polyols, sugars, nucleosides, vitamins) were tested individually and in binary/ternary combinations.
• mRNA formulations with varying osmolyte concentrations (0-30% w/v) were subjected to thermal stress (40°C for 5-14 days) and cold storage (4°C for 2.5 months).
• Thermostability was assessed using densitometric indices to quantify mRNA integrity.

Main Results:

• An optimized formulation of 80:20 taurine to uridine demonstrated robust mRNA protection (densitometric indices 0.833-0.875) at 15-30% w/v.
• Exceptional mRNA stability was observed at 1% w/v of taurine-uridine (0.966 ± 0.061) after 5 days at 40°C.
• A ternary taurine-uridine-sorbitol system showed peak performance at 5% w/v (0.917 ± 0.036), indicating a concentration-dependent design principle for thermostable mRNA.

Conclusions:

• Osmolyte effectiveness is dependent on both identity and formulation composition; ternary mixtures do not consistently outperform binary systems.
• The study establishes a concentration-dependent design principle for thermostable mRNA formulations, achieving over tenfold improvement in stability under thermal stress.
• Osmoytes present a significant potential strategy for enhancing the shelf-life and accessibility of mRNA vaccines.