Lamotrigine Hydrate Crystal Form for Stable Oral Liquid Dosing
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Solution Overview
Problem
Current lamotrigine formulations face issues with inaccurate dosing, low solubility, and poor physical stability, particularly in liquid forms, which are crucial for pediatric and dysphagia patients, and existing eutectics and solvates do not address these problems effectively.
Innovation Solution
Development of lamotrigine hydrate form A with specific XRPD peaks and a preparation method involving dispersing lamotrigine particles with a thickener in an aqueous phase at low temperature to form a stable suspension, ensuring consistent particle size and high purity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If lamotrigine is formulated as an oral liquid, then it facilitates administration to children and dysphagia patients, but it results in inaccurate dosing due to crystal formation and precipitation
Solution Approach 1:
The patent changes the physical-chemical parameters of lamotrigine by converting it from anhydrous form to a monohydrate crystalline form. This parameter change (adding water of crystallization) fundamentally alters the solubility and stability characteristics of the drug, enabling it to remain stable in aqueous oral liquid formulations without precipitation or crystal formation, thereby maintaining dosing accuracy while preserving administration convenience.
Solution Approach 2:
The patent creates a composite crystalline structure by forming a monohydrate complex between lamotrigine and water. This composite material approach combines the drug with a specific amount of water molecules in a defined stoichiometric ratio (1:1), resulting in a new crystalline phase that exhibits improved stability and solubility properties suitable for oral liquid formulations.
2Quantity of substance
If the concentration of lamotrigine in oral liquid is increased to meet clinical requirements, then therapeutic efficacy is improved, but solubility becomes insufficient without organic solvents
Solution Approach 1:
The patent changes the solubility parameter of lamotrigine through crystalline form modification. By converting to the monohydrate form, the drug achieves significantly improved aqueous solubility, allowing high concentrations to be formulated in organic-solvent-free oral liquids while maintaining compositional stability and preventing precipitation.
Solution Approach 2:
The patent replaces expensive and potentially harmful organic solvents with water as the vehicles for high-concentration lamotrigine formulation. This substitution uses a safe, inexpensive, and biocompatible medium (water) to achieve the required drug concentration, eliminating the need for organic solvents while maintaining solubility stability.
3Ease of manufacture
If common suspension methods are used for lamotrigine, then initial preparation is simple, but bulk crystals form after standing, leading to inaccurate dosing
Solution Approach 1:
The patent changes the crystalline state parameter of lamotrigine from anhydrous to monohydrate form. This parameter change fundamentally improves physical stability in suspension, preventing the formation of bulk crystals during storage while maintaining preparation simplicity. The monohydrate form remains stable in aqueous suspension without requiring complex stabilization measures.
4Quantity of substance
If pH is decreased to increase lamotrigine solubility, then solubility is improved to some extent, but the effect is limited and cannot achieve high concentration formulations
Solution Approach 1:
The patent changes the fundamental solubility parameter of lamotrigine through crystalline form modification rather than adjusting pH. By converting to the monohydrate form, the drug achieves inherently high aqueous solubility that allows high-concentration formulations without requiring extreme pH adjustments or complex formulation strategies, thereby achieving the desired solubility with simpler formulation approaches.
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 lamotrigine hydrate form A provides a stable and accurate dosing solution with prolonged physical stability, suitable for liquid formulations, addressing the limitations of existing lamotrigine preparations.
Implementation Method 1
lamotrigine hydrate form A
Implementation Method 2
eutectics or hydrates of a drug may effectively improve the crystallization and physicochemical properties of the drug through a hydrogen bond or other non-covalent bonds
Implementation Method 3
after standing at room temperature for 3 days, a large number of bulk crystals appeared and tended to become larger over time
Data Source
AI summary
The present invention relates to a crystalline form of a lamotrigine hydrate, a method for preparing the same and a composition comprising the same, and in particular, to a lamotrigine hydrate form A, a method for preparing the lamotrigine hydrate form A and a composition comprising the lamotrigine hydrate form A.