L-lysine-d-amphetamine Crystalline Salts for Moisture Stability
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Solution Overview
Problem
The existing solid-state forms of L-lysine-d-amphetamine, particularly the dimesylate salt, are highly hygroscopic and prone to deliquescence at moderate humidity levels, making them challenging to handle and store, which affects the reliability and safety of the drug product.
Innovation Solution
Development of crystalline salts of L-lysine-d-amphetamine with specific acid partners such as adipic acid, p-toluenesulfonic acid, fumaric acid, and oxalic acid, which are less hygroscopic and more stable, characterized by unique powder X-ray diffraction patterns and reduced water uptake at higher humidity levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If L-lysine-d-amphetamine dimesylate is used as the salt form, then the drug can be provided in a crystalline form with defined structure, but the salt becomes highly hygroscopic and prone to deliquescence at moderate humidity levels
Solution Approach 1:
The patent changes the chemical parameters of the salt formation by using alternative acids (fumaric acid, oxalic acid, adipic acid, p-toluenesulfonic acid) instead of methanesulfonic acid, thereby modifying the hygroscopic properties while maintaining crystalline structure stability
Solution Approach 2:
The patent creates composite salt structures by combining L-lysine-d-amphetamine with different acid counterions, where each acid forms a distinct crystalline salt with different hygroscopic characteristics, allowing selection of salts with optimal stability properties
2Reliability
If L-lysine-d-amphetamine dimesylate is used, then the drug can be formulated with known pharmacological properties, but handling and storage become challenging due to deliquescence at moderate humidity
Solution Approach 1:
The patent modifies the salt's physical-chemical parameters by selecting acids with different hygroscopicity levels, thereby improving ease of handling and storage while maintaining pharmacological reliability through consistent active ingredient delivery
3Ease of manufacture
If existing salt forms are used, then the preparation method is well-established, but the solid-state form exhibits poor stability against moisture
Solution Approach 1:
The patent changes the chemical composition parameters by introducing alternative acid salts while maintaining the established crystallization and purification processes, thereby achieving improved moisture stability without fundamentally altering the manufacturing approach
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 new crystalline salts are easier to handle and store due to reduced hygroscopicity and stability, facilitating pharmaceutical processing and maintaining drug efficacy and safety.
Implementation Method 1
The new crystalline salts are easier to handle and store due to reduced hygroscopicity and stability
Implementation Method 2
characterized by unique powder X-ray diffraction patterns
Data Source
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AI summary
The present invention relates to crystalline salts of L-lysine-d-amphetamine and to a pharmaceutical composition comprising one or more of said crystalline salts, preferably in a predetermined and/or effective amount, and at least one pharmaceutically acceptable excipient. The pharmaceutical composition of the present invention can be used as a medicament, in particular for the treatment of Attention Deficit and Hyperactivity Disorder (ADHD) and Binge Eating Disorder (BED) symptoms. A is selected from the group consisting of adipic acid, p-toluene sulfonic acid, fumaric acid and oxalic acid.