PDE3/PDE4 Dual Inhibitor Crystal Form for COPD Solubility and Stability

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Solution Overview

Problem

Existing PDE3/PDE4 inhibitors, such as RPL554 and RPL565, exhibit poor solubility, high plasma clearance, and insufficient anti-inflammatory effects, necessitating the development of a compound with improved PDE3/4 inhibitory activity and favorable physicochemical properties for effective treatment of chronic obstructive pulmonary disease (COPD).

Innovation Solution

A crystalline form of a compound with specific X-ray diffraction peaks and thermal properties is developed, providing enhanced PDE3/PDE4 inhibitory activity, stability, and solubility, suitable for inhalational administration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing PDE3/PDE4 inhibitors (RPL554, RPL565) are used, then bronchodilation effect is achieved, but solubility is poor and plasma clearance is high

Engineering Contradiction:
Improvebronchodilation effectVSAvoidsolubility
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent modifies the molecular structure of PDE3/PDE4 inhibitors by changing chemical parameters (introducing specific substituents at positions 2 and 6 of the pyridine ring, adjusting the R1-R6 groups) to improve solubility while maintaining bronchodilation activity. This structural parameter change enables better dissolution and reduced plasma clearance.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If existing PDE3/PDE4 inhibitors (RPL554, RPL565) are used, then bronchodilation effect is achieved, but anti-inflammatory effect is insufficient

Engineering Contradiction:
Improvebronchodilation effectVSAvoidanti-inflammatory effect
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent designs a dual-targeting inhibitor that simultaneously activates both PDE3 (for bronchodilation) and PDE4 (for anti-inflammatory effects). The compound structure incorporates multiple functional groups that enable interaction with both enzyme targets, achieving multi-functionality in a single agent to address both bronchodilation and inflammation.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If combination therapy is used to achieve therapeutic effect, then efficacy is improved, but administration complexity increases

Engineering Contradiction:
Improvetherapeutic effectVSAvoidadministration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the functions of separate PDE3 and PDE4 inhibitors into a single dual-targeting compound. This consolidation eliminates the need for combination therapy, simplifying administration while maintaining the synergistic therapeutic effect of targeting both enzymes simultaneously.

Inventive Principle:
Principle #5Merging (Combining)

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 crystalline form addresses the limitations of existing inhibitors by offering improved bronchodilation and anti-inflammatory effects, enhancing therapeutic efficacy for COPD treatment.

Implementation Method 1

having diffraction peaks in an X-ray powder diffraction pattern using Cu Kα radiation at the following 2θ angles: 4.14±0.2°, 6.98±0.2°, 8.20±0.2° and 11.50±0.2°

Methodology Applied
Scientific EffectX-ray diffraction: Diffraction

Implementation Method 2

the crystalline form A has endothermic peaks in a differential scanning calorimetry curve at 146.23±2 °C and/or 162.19±2 °C

Methodology Applied
Scientific EffectDifferential scanning calorimetry: Calorimetry

Data Source

PatentEP4643947A9Crystal of PDE3/PDE4 dual inhibitor and use thereof
Publication Date: 2026.02.18 CHIA TAI TIANQING PHARMA GRP CO LTD
  • EP4643947A9 patent drawingFigure 1~2
  • EP4643947A9 patent drawingFigure 3~4
  • EP4643947A9 patent drawingFigure 5~6

AI summary

Provided are a crystal of a tricyclic compound as shown in formula (I) or a pharmaceutically acceptable salt thereof and a preparation method therefor, and the use thereof in preparing a drug for treating PDE3- and/or PDE4-related diseases.