Glutamate-Buffered G-CSF Formulation Stability
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Solution Overview
Problem
Conventional G-CSF formulations are unstable, particularly non-glycosylated recombinant forms, prone to adsorption, dimerization, and chemical modifications, leading to loss of activity and potential immune responses, especially under mechanical stress and varying temperatures.
Innovation Solution
Aqueous G-CSF formulations buffered with glutamic acid/glutamate at a pH of 3.5 to 4.8, which are essentially free from sugars, aminosugars, and amino acids other than glutamic acid, providing long-term stability and resistance to mechanical stress and elevated temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional G-CSF formulations are used, then the protein can be administered for therapeutic use, but the formulations are unstable and prone to aggregation, adsorption, and chemical modifications leading to loss of activity
Solution Approach 1:
The patent applies parameter changes by optimizing the pH range to 3.5-4.8 and specifying precise concentrations of glutamate buffer (1-50 mM), surfactants (0.01-1% w/v), and sugars (1-10% w/v). These parameter adjustments create a formulation environment that minimizes protein aggregation, adsorption, and chemical modifications while maintaining therapeutic efficacy.
Solution Approach 2:
The invention uses a composite formulation system combining multiple stabilizing components: glutamate buffer for pH control, surfactants (such as polysorbates or polyoxylines) to prevent adsorption and aggregation, and sugars (such as sucrose or trehalose) to provide structural stability. This multi-component composite approach addresses multiple degradation pathways simultaneously.
2Reliability
If proteins and peptides of human and animal origin are used as stabilizers, then G-CSF stability is improved, but antigenic properties cause undesired immunological reactions
Solution Approach 1:
The patent replaces protein-based stabilizers with non-protein alternatives that are immunologically inert. Specifically, synthetic surfactants (polysorbates, polyoxylines) and carbohydrates (sugars like sucrose and trehalose) are used instead of animal-derived proteins. These substitutes provide equivalent stabilizing effects without antigenic properties, eliminating the risk of immunological reactions.
3Stability of the object's composition
If no buffer is used to avoid aggregation, then aggregation is reduced, but long-term stabilization at pH above 4.0 is not achieved
Solution Approach 1:
The patent resolves this contradiction by changing the buffer system parameters: using glutamate buffer at controlled concentrations (1-50 mM) within a specific pH range (3.5-4.8). This buffered environment prevents both aggregation and long-term degradation, achieving stability that neither buffered nor completely buffer-free formulations can provide alone.
4Ease of operation
If G-CSF formulations are subjected to mechanical stress during transport, then distribution is enabled, but dimerization and higher aggregate formation occur leading to loss of activity
Solution Approach 1:
The patent introduces surfactants as intermediary substances that mediate between the G-CSF protein and the mechanical stress environment. These surfactants adsorb to protein surfaces and formulation container walls, creating a protective interface that prevents stress-induced aggregation and dimerization during transport and handling.
Data Source
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AI summary
The invention relates to stable glutamate-buffered G-CSF formulations having a pH of from 3.5 to 4.8. The invention further concerns lyophilisates and powders obtainable from such formulations, and to pharmaceutical kits containing such lyophilisates and powders.