Sulfate Salt Stabilization of Poxvirus Liquid Formulations
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Solution Overview
Problem
Poxvirus vaccines, such as those containing vaccinia virus or modified vaccinia Ankara (MVA), face challenges in maintaining stability and potency during storage due to envelope instability, leading to issues like aggregation, conformational changes, and reduced infectivity, especially under varying temperature conditions and agitation.
Innovation Solution
Incorporating a sulfate salt, preferably sodium sulfate, at concentrations between 5 mM and 300 mM in a buffer with a pH ranging from 6.0 to 8.5, which enhances thermal stability and resistance to agitation, thereby minimizing aggregation and maintaining viral infectivity and potency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If poxvirus is stored in conventional liquid formulations, then the virus can be stored for extended periods, but the viral envelope becomes unstable leading to aggregation, conformational changes, and loss of infectivity
Solution Approach 1:
The patent applies parameter changes by optimizing the pH range (6.0-8.5) and ionic strength of the buffer solution to stabilize the viral envelope. This chemical parameter optimization prevents aggregation and conformational changes, maintaining viral infectivity during extended storage without requiring freeze-drying or complex additives.
Solution Approach 2:
The patent uses a specifically formulated buffer solution as an intermediary substance that mediates between the virus and the storage environment. The buffer acts as a protective medium that maintains pH stability and ionic balance, preventing direct interaction between the viral envelope and destabilizing factors in the storage conditions.
2Reliability
If freeze-dried formulations are used to improve stability, then viral infectivity is better preserved, but the storage and administration process becomes more complex requiring reconstitution
Solution Approach 1:
The patent extracts the essential stabilizing components (pH buffer and ionic strength agents) from complex freeze-drying formulations, creating a simplified liquid formulation that achieves comparable stability without requiring the removal of water through freeze-drying. This eliminates the need for reconstitution while maintaining viral infectivity.
Solution Approach 2:
Instead of using freeze-drying to remove water and stabilize the virus, the patent inverts the approach by maintaining a controlled aqueous environment with optimized pH and ionic strength. This alternative stabilization strategy achieves reliability without the complexity of lyophilization and reconstitution procedures.
3Ease of operation
If the virus is stored at elevated temperatures to simplify logistics, then distribution becomes easier, but thermal instability causes loss of potency and increased aggregation
Solution Approach 1:
The patent applies parameter changes by optimizing the buffer capacity and ionic strength to increase the thermal stability threshold of the virus. The pH range (6.0-8.5) and sulfate salt concentration are specifically tuned to prevent thermal denaturation and aggregation, allowing the virus to withstand elevated storage temperatures without significant loss of infectivity.
Solution Approach 2:
The patent provides beforehand cushioning against thermal stress by incorporating a robust buffer system that anticipates and counteracts temperature fluctuations. The buffer capacity is designed to absorb thermal energy changes and maintain pH stability, cushioning the virus against thermal damage during distribution and storage.
4Ease of manufacture
If conventional buffer formulations are used, then the formulation is simple to prepare, but the virus experiences pH changes and aggregation during storage
Solution Approach 1:
The patent applies parameter changes by optimizing the buffer capacity and pH range (6.0-8.5) to maximize pH stability during storage. The sulfate salt concentration is specifically adjusted to prevent aggregation while maintaining solubility. These parameter optimizations achieve enhanced stability without significantly complicating the formulation preparation process.
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 compositions demonstrate improved stability and retention of infectivity, allowing for extended shelf life at various temperatures, including room temperature and below, with minimal loss of viral titer and immunogenicity, even after freeze-thaw cycles and agitation.
Implementation Method 1
a sulfate salt and a buffer such as a phosphate or a Tris-buffer for use in long-term storage
Implementation Method 2
a sulfate salt and a buffer such as a phosphate or a Tris-buffer for use in long-term storage
Data Source
AI summary
Described herein are compositions and pharmaceutical compositions including poxviruses, in particular vaccinia virus such as modified vaccinia Ankara (MVA) virus, a sulfate salt at a concentration between about 5 mM and 300 mM and a buffer, wherein the composition has a pH of between about 6.0 and 8.5. Also described are methods for stabilizing a poxvirus composition by preparing said viral formulation.