Adenovirus Spray Drying with Mannitol-Dextran Matrix
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Solution Overview
Problem
Adenoviral vectors used in vaccines are unstable at mild temperatures, leading to protein denaturation and loss of infectivity, making storage at -80°C necessary, which is impractical for global vaccination efforts, especially in developing countries, and pre-existing immunity to Human Adenovirus Type 5 (AdHu5) limits its application.
Innovation Solution
Development of a thermally stable adenovirus formulation through spray drying with a binary excipient matrix of dextran and mannitol, which maintains at least 40% adenovirus activity, allowing storage and use at elevated temperatures without significant loss of function.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If adenoviral vectors are stored in aqueous medium at elevated temperatures, then thermal stability is improved, but protein denaturation and loss of viral infectivity occur
Solution Approach 1:
The patent changes the physical state parameter of the adenoviral vector from liquid (aqueous medium) to solid (freeze-dried powder), and modifies the chemical environment by introducing protective excipients. This parameter transformation enables the virus to withstand elevated temperatures without denaturation, resolving the contradiction between storage temperature and viral infectivity maintenance
Solution Approach 2:
The patent creates a composite formulation by combining adenoviral vectors with protective excipients (sugars, polymers, amino acids) in a freeze-dried matrix. This composite structure provides thermal protection to the viral particles, allowing storage at elevated temperatures while maintaining infectivity, thus resolving the contradiction between temperature stability and viral function
2Reliability
If adenoviral vectors are stored at -80°C, then viral infectivity is maintained, but cold chain requirements increase storage complexity and cost
Solution Approach 1:
The patent transforms the storage state from liquid to solid (freeze-dried powder) and modifies the chemical environment with protective excipients. This parameter change enables the virus to be stored at ambient temperatures without significant infectivity loss, eliminating the need for complex cold chain infrastructure and resolving the contradiction between maintaining viral infectivity and reducing storage complexity
3Temperature
If adenoviral vectors are dispersed in amorphous matrix, then thermal stability is improved, but moisture sensitivity increases
Solution Approach 1:
The patent creates a composite excipient system combining amorphous matrix materials (sugars, polymers) with crystalline components (amino acids, salts). This composite structure provides both thermal protection through the amorphous phase and moisture resistance through the crystalline phase, resolving the contradiction between thermal stability and moisture sensitivity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The spray-dried adenovirus formulation in a mannitol-dextran matrix provides enhanced thermal stability and moisture resistance, enabling effective storage and administration at ambient temperatures, overcoming the limitations of existing adenoviral vector stability and pre-existing immunity.
Implementation Method 1
Evaporation of heated aqueous droplets results in precipitation of the dissolved solutes and suspended materials
Implementation Method 2
Evaporation of heated aqueous droplets results in precipitation of the dissolved solutes and suspended materials
Implementation Method 3
A promising approach capable of increasing thermal stability of labile vectors is through their dispersion within the amorphous phase of a solid matrix, termed as vitrification
Data Source
AI summary
The present application includes stabilized adenovirus compositions comprising an adenovirus and an excipient, wherein the excipient comprises a mixture of dextran and mannitol in amounts effective to maintain at least 40% of the adenovirus activity after spray drying.