Isavuconazonium Sulfate Purification by Crystallization and Precipitation
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Solution Overview
Problem
Existing methods for purifying isavuconazonium sulfate, a prodrug of the azole antifungal agent isavuconazole, face challenges such as low yield and epimer enrichment, especially when starting from crude materials of lower purity, and are not suitable for commercial scale-up due to the use of hydrogen peroxide, which leads to product degradation.
Innovation Solution
A method involving a mixture of isavuconazonium sulfate and an aliphatic alcohol at pH 1 to 6, followed by crystallization and addition of an aprotic organic solvent, selectively precipitating different epimers to achieve the desired molar ratio of 1.2:1 to 1:1.2 required for commercial products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hydrogen peroxide is used in the crystallization process, then the product can be obtained, but significant degradation of the product occurs
Solution Approach 1:
The patent removes hydrogen peroxide from the crystallization process entirely, replacing it with alternative reagents that do not cause product degradation. This extraction of the harmful element resolves the contradiction between obtaining the product and preventing degradation.
Solution Approach 2:
The patent uses alternative reagents that are less harsh and do not cause degradation, replacing the problematic hydrogen peroxide with milder chemical agents that achieve the same crystallization effect without harmful side effects.
2Manufacturing precision
If conventional crystallization methods are used, then purification is achieved, but the yield is low when starting from crude material of lower purity
Solution Approach 1:
The patent performs preliminary pH adjustment and solvent selection before the crystallization step, optimizing the conditions in advance to maximize yield from crude materials. This preliminary preparation ensures that the crystallization step can achieve both high purity and high yield simultaneously.
Solution Approach 2:
The patent modifies key parameters including pH range (1-6), solvent composition (aliphatic alcohol and aprotic organic solvent), and temperature conditions to optimize the crystallization process for both purity and yield from crude starting materials.
3Manufacturing precision
If conventional crystallization methods are used, then purification is achieved, but the product is highly enriched for one epimer whereas the commercial product requires a molar epimer ratio of 1.2:1 to 1:1.2
Solution Approach 1:
The patent adjusts pH and solvent composition parameters to control the crystallization behavior of different epimers, enabling precise control over the epimer ratio in the final product to match the required 1.2:1 to 1:1.2 commercial specification.
Solution Approach 2:
The patent uses a two-step crystallization process where the first step selectively crystallizes one epimer and the second step adjusts the ratio, using partial crystallization followed by ratio adjustment to achieve the target epimer distribution.
4Manufacturing precision
If existing purification methods are used, then some purification is achieved, but the methods are not suitable for commercial scale-up
Solution Approach 1:
The patent divides the purification process into distinct sequential steps (pH adjustment, first crystallization, second crystallization) that can be independently optimized and scaled, making the overall process suitable for commercial manufacturing while maintaining high purity.
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 method enhances the yield and purity of isavuconazonium sulfate by selectively crystallizing epimer B in the first step and precipitating epimer A in the second, achieving the desired epimer ratio suitable for commercialization.
Implementation Method 1
allowing a first portion of the sulfate salt of the compound of formula I to crystalize from the mixture
Implementation Method 2
adding an aprotic organic solvent to the mixture and allowing an additional portion of the sulfate salt of the compound of formula I to precipitate from the mixture
Data Source
AI summary
The invention provides methods for purifying isavuconazonium sulfate comprising the steps of —(a) providing a mixture comprising the sulfate salt of the compound of formula (I) and an aliphatic alcohol, wherein the pH of the mixture is in the range of about pH 1 to about pH 6; —(b) allowing a first portion of the sulfate salt of the compound of formula (I) to crystalize from the mixture; and —(c) adding an aprotic organic solvent to the mixture and allowing an additional portion of the sulfate salt of the compound of formula (I) to precipitate from the mixture.