Stable CROWN Radiopharmaceutical Formulations Against Dissociation
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Solution Overview
Problem
Existing radiopharmaceutical compositions using the CROWN chelator face challenges with stability and dissociation, particularly due to trans-metalation and radiolytic degradation, which affect their shelf-life and effectiveness in clinical applications.
Innovation Solution
Formulations with specific pH ranges (5-8) and stabilizing agents, combined with controlled storage conditions, ensure high radiochemical purity and stability of CROWN-based radiolabeled compounds, maintaining purity above 90% for extended periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If CROWN chelator is used to complex radionuclides, then chelation speed and initial stability are improved, but dissociation occurs over time due to trans-metalation and radiolytic degradation
Solution Approach 1:
The patent applies preliminary action by adding stabilizing agents (ascorbic acid, gentisic acid, ethanol) to the radiopharmaceutical composition before storage. These agents are pre-introduced to prevent radiolytic degradation and trans-metalation reactions that would otherwise occur during storage, thereby maintaining complex stability without sacrificing the fast chelation kinetics of CROWN
Solution Approach 2:
The patent converts the harmful effects of radiolysis and trans-metalation into beneficial outcomes by using stabilizing agents that scavenge reactive species and prevent degradation. The ascorbic acid and gentisic acid convert harmful radiation-induced radicals into harmless products, while ethanol prevents trans-metalation, thus transforming the detrimental radioactive environment into a stable storage condition
2Duration of action of stationary object
If radiopharmaceutical compositions are stored for extended periods, then shelf-life is improved, but radiochemical purity decreases due to dissociation and degradation
Solution Approach 1:
The patent implements preliminary action by incorporating stabilizing agents (ascorbic acid at 0.1-10 mM, gentisic acid at 0.1-10 mM, and ethanol at 1-20% v/v) into the composition before storage. These agents are pre-positioned to counteract radiolytic degradation and trans-metalation throughout the storage period, enabling extended shelf-life (at least 5 days at 4°C) while maintaining radiochemical purity above 90%
Solution Approach 2:
The patent applies parameter changes by optimizing the pH of the formulation to a specific range (5.5-7.5, preferably 6.0-7.0) and controlling storage temperature (4°C refrigeration). These parameter adjustments, combined with stabilizing agents, significantly extend the shelf-life while preserving radiochemical purity, allowing centralized manufacturing and distribution
3Stability of the object's composition
If pH is adjusted to optimize stability, then complex stability is improved, but formulation complexity increases
Solution Approach 1:
The patent applies parameter changes by establishing an optimal pH range (5.5-7.5, preferably 6.0-7.0) for the radiopharmaceutical formulation. This pH optimization, combined with simple stabilizing agents (ascorbic acid, gentisic acid, ethanol), achieves high complex stability without requiring complex formulation systems. The approach uses straightforward pH adjustment and common pharmaceutical excipients rather than complex stabilizing systems
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 formulations provide stable radiopharmaceutical compositions with high radiochemical purity, suitable for medical imaging and treatment, by minimizing dissociation and degradation, thus ensuring effective targeting and specificity of the compounds.
Implementation Method 1
DOTA, with the structure shown below in Formula 1, has been studied for attaching radionuclides (e.g., 225Ac) to peptides, antibodies and other targeting molecules.
Implementation Method 2
TM is a cellular antigen binding moiety
Implementation Method 3
The use of alpha emitters for cancer therapy has two distinct advantages over beta emitter therapies.
Implementation Method 4
The major radionuclides used in RLT are beta emitting radionuclides, including lutetium-177, yttrium-90, and strontium-89.
Implementation Method 5
Radiolytic degradation is another major factor affecting the shelf life of therapeutic radiopharmaceuticals.
Data Source
AI summary
Stabilized radiopharmaceutical formulations or dosage forms comprising radiolabeled conjugates of formula RC-L-TM are disclosed. Methods of making and using stabilized radiopharmaceutical formulations or dosage forms comprising the radiolabeled conjugates are also disclosed, including the preparation and stabilization of targeted radiodiagnostic and radiotherapeutic compounds comprising the radiolabeled conjugate.