Anhydrous Imidazole Polymorphs for Pharmaceutical Stability
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Solution Overview
Problem
Existing methods for preparing N-[({2-[4-(2-Ethyl-4,6-dimethyl-1H-imidazo[4,5-c]pyridin-1-yl)phenyl]ethyl}amino)carbonyl]-4-methylbenzenesulfonamide result in an unstable solvate, making it challenging to achieve a pharmaceutically suitable, pure, crystalline form with consistent performance characteristics for pharmaceutical formulations.
Innovation Solution
Development of polymorphic forms A and B, characterized by specific X-ray diffraction patterns, differential scanning calorimetry, and infrared spectra, which are anhydrous, non-hygroscopic, and high-melting, providing a stable and reproducible crystalline form suitable for pharmaceutical use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If previously known methods are used to prepare the compound, then the compound can be produced, but an unstable solvate is formed which is not suitable for pharmaceutical formulations
Solution Approach 1:
The patent applies parameter changes by modifying crystallization conditions including solvent selection (acetone, ethyl acetate, dichloromethane, toluene, isopropyl alcohol, n-butyl alcohol), temperature parameters (cooling rates, storage temperatures), and pH control during synthesis to transform the unstable solvate into stable anhydrous polymorphic forms A and B suitable for pharmaceutical use
Solution Approach 2:
The patent utilizes phase transitions by controlling the crystallization process from solution to solid state, and by managing solvate-to-anhydrous form transitions through controlled drying and storage conditions, thereby obtaining stable polymorphic forms with defined crystal structures
2Manufacturing precision
If the unstable solvate form is used, then the compound can be obtained, but it lacks consistent performance characteristics for pharmaceutical formulations
Solution Approach 1:
The patent establishes precise manufacturing parameters including specific solvent systems, controlled cooling rates, pH ranges during synthesis, and storage conditions (temperature, humidity control) to consistently produce polymorphic forms A and B with reproducible performance characteristics across batches
Solution Approach 2:
The patent implements quality control feedback through characterization techniques (PXRD, DSC, HPLC, NMR) to verify the formation of desired polymorphic forms and detect any solvate contamination, allowing process adjustments to maintain consistent performance characteristics
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
Polymorph Forms A and B offer improved stability and bioavailability, ensuring consistent performance in pharmaceutical formulations, particularly for the treatment of pain and inflammation-associated disorders.
Implementation Method 1
characterised by a powder X-ray diffraction pattern (PXRD) obtained by irradiation with Cu Kα radiation
Implementation Method 2
differential scanning calorimetry (DSC) in which it exhibits an endothermic thermal event at about 160° C.
Implementation Method 3
an infrared (IR) spectrum (KBr) which shows absorption bands at 2985, 2920, 2871, 1706, 1641, 1596, 1515, 1456, 1369, 1340, 1294, 1249, 1224, 1164, 1124, 1091, 1016, 902, 815, 659, 574 and 549 cm−1
Data Source
AI summary
The invention relates to the essentially pure Λ/-[({2-[4-(2-Ethyl-4,6-dimethyl-1H-imidazo[4,5-c]pyridin-1-yl)phenyl]ethyl}amino)carbonyl]-4-methylbenzenesulfonamide Polymorph Forms A and B and to processes for the preparation of, compositions containing and to the uses of, such crystal forms.