Lanthanide Chelate Formulation Excess Control
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Solution Overview
Problem
Existing pharmaceutical formulations of lanthanide chelates, such as gadolinium, face challenges in tolerance due to potential unwanted release of lanthanide ions, leading to risks like nephrological systemic fibrosis, especially in repeated administrations for MRI contrast media, where current solutions do not adequately ensure safe and stable concentrations of excess chelates.
Innovation Solution
A process for preparing macrocyclic chelate formulations like DOTA, involving steps of mixing and adjusting chelate and lanthanide quantities to achieve a precise excess of free chelate in the final solution, followed by complexation and optional transformation into a powder form, ensuring a concentration range of 0.002 to 0.4% mol/mol, with additional optimization through precipitation methods to maintain target proportions of complexed and free chelate entities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an excess of chelate is added to compensate for unwanted release of lanthanide, then the stability and tolerance of the formulation is improved, but the manufacturing precision and control of exact chelate concentration becomes more difficult
Solution Approach 1:
The patent applies parameter changes by precisely controlling the molar ratio of chelate to lanthanide (maintaining L/Ln ≥ 1.0 with specific excess ranges of 0.002 to 0.4%). This quantitative parameter control ensures sufficient excess chelate to bind released lanthanide while maintaining manufacturing precision through defined concentration ranges.
Solution Approach 2:
The patent implements feedback control through quality control measurements that determine the actual free chelate concentration in the final formulation. Based on these measurements, adjustments are made to ensure the excess chelate falls within the target range of 0.002 to 0.4% mol/mol, allowing correction of any deviations during manufacturing.
2Object-affected harmful factors
If the excess chelate concentration is kept within a narrow range (0.002 to 0.4% mol/mol), then the safety and tolerance are improved, but the complexity of the manufacturing process increases
Solution Approach 1:
The patent defines specific parameter ranges for excess chelate concentration (0.002 to 0.4% mol/mol, with preferred ranges of 0.01-0.3% and most preferred 0.025-0.25%). These quantified parameters provide clear manufacturing targets that balance safety requirements with process feasibility, reducing the narrow range complexity while ensuring patient safety.
Solution Approach 2:
The patent applies preliminary action by pre-calculating and pre-mixing the chelate and lanthanide in the correct proportions to achieve the desired excess chelate concentration before final formulation completion. This advance preparation ensures the critical concentration parameter is established early, simplifying subsequent manufacturing steps.
3Measurement precision
If precise measurement and adjustment of chelate and lanthanide quantities is performed after complexation, then the concentration accuracy is improved, but the production time and productivity are reduced
Solution Approach 1:
The patent applies preliminary action by performing the complexation of chelate and lanthanide before the final formulation steps, allowing the reaction to proceed under controlled conditions. This timing ensures complete complexation occurs while enabling subsequent precise measurement and adjustment of free chelate concentration without delaying the overall production schedule.
Solution Approach 2:
The patent maintains continuity of useful action by integrating the measurement and adjustment steps into the continuous manufacturing flow. Rather than interrupting production for separate analysis and correction, the process continuously monitors and adjusts chelate concentration to maintain the target excess range, minimizing downtime and maintaining productivity.
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
This approach ensures a stable and secure pharmaceutical formulation with a controlled excess of free chelate, enhancing tolerance and maintaining effective concentrations of lanthanide chelates, thereby reducing the risk of adverse reactions and improving safety for patients undergoing repeated diagnostic or therapeutic procedures.
Implementation Method 1
mixing the chelate and the lanthanide in order to obtain the complexation of the lanthanide by the macrocyclic chelate
Implementation Method 2
This excess is intended to compensate for an undesired release of the lanthanide, the excess chelate complexing the lanthanide (metal ion Gd3+) released
Implementation Method 3
precipitation of the complexing solution obtained in step 1) or in step 2) in an organic solvent so as to obtain a powder of chelate-lanthanide complex
Data Source
AI summary
The present invention relates to a method for preparing a pharmaceutical composition of lanthanide chelate in powder form, said powder including an excess of free chelate of 0.002% to 0.4% mol/mol, said method including the following consecutive steps: 1) step 1: mixing the chelate and the lanthanide in order to carry out the complexing of the lanthanide by the chelate, the resulting complexing solution including, in addition to the lanthanide-chelate complex, an amount X1 of excess free chelate; 2) step 2: preferably measuring X1 and optionally adjusting X1 to obtain a value of X1 of 0.002 to 0.4% mol/mol; 3) step 3: precipitating the complexing solution obtained in step 1) or in step 2) in an organic solvent in order to produce a lanthanide-chelate complex powder, the powder containing an amount X2 of excess free chelate, 4) step 4: optionally adjusting X2 such that: 4.a) X2 is 0.002% to 0.4%, specifically 0.02% to 0.3% mol/mol, very advantageously 0.025% to 0.25% mol/mol; 4.b) X2 is 0.2 to 2 times X1, in particular 0.5 to 1.5 times X1, X2 advantageously belonging to the range: [0.5 - 0.95]*X1, or to the range [1.05 - 1.3]*X1.5); step 5: preferably measuring X2.