Diaminopyrimidine Salt Crystal Forms for P2X3 Bioavailability

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Solution Overview

Problem

Existing P2X3 and/or P2X2/3 receptor antagonists face challenges in terms of physical properties, solubility, dissolution rate, stability, and bioavailability, which affect their efficacy and safety in treating pain-related diseases.

Innovation Solution

Development of crystalline forms of 5-((2-ethynyl-5-isopropylpyridin-4-yl)oxy)pyrimidine-2,4-diamine salts with specific molar ratios, such as hydrochloride, citrate, sulfate, and mesylate, which enhance physical properties, stability, and bioavailability, facilitating better pharmaceutical formulations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing P2X3 and/or P2X2/3 receptor antagonists are used, then the therapeutic effect is achieved, but the physical properties, solubility, dissolution rate, and stability are insufficient

Engineering Contradiction:
Improvetherapeutic effectVSAvoidphysical properties and stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent applies parameter changes by converting the compound into different salt forms (hydrochloride, citrate, sulfate, mesylate) with specific molar ratios. This chemical parameter modification fundamentally alters the physical properties including solubility, dissolution rate, and stability while preserving the core therapeutic activity against P2X3 and/or P2X2/3 receptors.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates composite crystalline structures by combining the diaminopyrimidine compound with various counterions in specific stoichiometric ratios. These composite crystalline forms integrate multiple components into a unified solid structure that exhibits improved physical properties compared to the parent compound alone.

Inventive Principle:
Principle #40Composite materials

2Reliability

If existing P2X3 and/or P2X2/3 receptor antagonists are used, then the pain treatment effect is achieved, but the bioavailability is limited

Engineering Contradiction:
Improvepain treatment effectVSAvoidbioavailability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

By changing the salt form parameters of the compound, the patent optimizes bioavailability. The selected salt forms (particularly hydrochloride, citrate, sulfate, and mesylate) exhibit enhanced solubility and dissolution characteristics that directly improve absorption and bioavailability while maintaining the pain treatment efficacy.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If existing P2X3 and/or P2X2/3 receptor antagonists are used, then the receptor antagonism is achieved, but the toxicity from drug accumulation occurs

Engineering Contradiction:
Improvereceptor antagonismVSAvoidtoxicity from drug accumulation
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent modifies the chemical parameters by forming salts with specific counterions, which alters the pharmacokinetic profile. The new crystalline forms exhibit reduced drug accumulation and lower toxicity while preserving the desired receptor antagonism, likely due to improved solubility and metabolic characteristics.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If existing P2X3 and/or P2X2/3 receptor antagonists are used, then the therapeutic activity is achieved, but the dissolution rate is insufficient

Engineering Contradiction:
Improvetherapeutic activityVSAvoiddissolution rate
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The invention changes the physical-chemical parameters by creating salt forms with specific counterions and molar ratios. This fundamentally improves the dissolution rate of the compound while maintaining therapeutic activity, as the ionic interactions in the salt forms enhance solubility and breakdown in aqueous environments compared to the parent compound.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3964500B1Salt of diaminopyrimidine compounds, and solid form thereof, preparation method therefor and use thereof
Publication Date: 2025.12.03 BEIJING TIDE PHARMACEUTICAL CO LTD
  • EP3964500B1 patent drawingFigure 1~2
  • EP3964500B1 patent drawingFigure 3~4
  • EP3964500B1 patent drawingFigure 5~6

AI summary

The present invention relates to a salt of 5-((2-ethynyl-5-isopropylpyridin-4-yl)oxy)pyrimidine-2,4-diamine and a solid form thereof, a method for preparing the solid form and a pharmaceutical composition comprising the solid form, as well as a use of the solid form for preventing or treating diseases modulated by P2X3 and/or P2X2/3 receptor antagonists.