Cetagliptin Phosphate Crystallization for Improved Druggability

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Solution Overview

Problem

Cetagliptin in its free base form is a viscous oil with poor druggability, and there are no reports on its salts or crystal forms, limiting its pharmaceutical applications.

Innovation Solution

Development of crystalline phosphate salts of cetagliptin in specific crystal forms, such as form B, with defined X-ray powder diffraction patterns and thermal properties, and a 1:1 molar ratio with phosphoric acid, prepared through solvent evaporation or induced crystallization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If cetagliptin is used in free base form, then the chemical structure is simple, but the druggability is poor and it forms viscous oil

Engineering Contradiction:
ImprovedruggabilityVSAvoidphysical form
Core Design Contradiction:
Ease of manufactureVSShape

Solution Approach 1:

The patent applies parameter changes by converting cetagliptin from free base form to phosphate salt form, which fundamentally changes the physical and chemical parameters of the compound. This transformation converts the viscous oil into a crystalline solid with defined melting point and solubility characteristics, thereby improving druggability while maintaining the core chemical structure

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material by forming a salt between cetagliptin (compound of formula I) and phosphoric acid. The resulting cetagliptin phosphate salt combines the pharmacological activity of cetagliptin with the beneficial physical properties of the phosphate salt form, including improved crystallinity, solubility, and stability

Inventive Principle:
Principle #40Composite materials

2Stability of the object's composition

If crystalline phosphate salts are developed, then the crystallinity and stability are improved, but the manufacturing process complexity increases

Engineering Contradiction:
Improvecrystalline stabilityVSAvoidprocess complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent utilizes phase transitions by controlling the crystallization process from solution to obtain specific crystal forms (Form A, Form B, and amorphous form). By manipulating solvent evaporation, cooling rates, and crystallization conditions, the patent achieves controlled phase transition from liquid solution to solid crystal, thereby improving stability while managing process complexity through systematic optimization

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The patent applies preliminary action by pre-screening multiple solvents and crystallization conditions to identify the optimal parameters for obtaining stable crystal forms. This preliminary optimization work establishes standardized preparation methods that simplify subsequent manufacturing processes while ensuring consistent product quality and stability

Inventive Principle:
Principle #10Preliminary action

3Reliability

If multiple crystal forms are screened, then the pharmaceutical effect is optimized, but the time and resources for development increase

Engineering Contradiction:
Improvepharmaceutical effectVSAvoiddevelopment time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies segmentation by systematically dividing the crystal form development into distinct categories (Form A, Form B, and amorphous form), each with specific preparation methods and characterization protocols. This segmented approach allows for organized screening and evaluation of different crystal forms, enabling efficient comparison and selection based on pharmaceutical performance criteria

Inventive Principle:
Principle #1Segmentation

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 phosphate form B exhibits high crystallinity, low hygroscopicity, good stability, and improved oral bioavailability, offering a better choice for drug development with effective inhibition of dipeptidyl peptidase and reduced hypoglycemic risk.

Implementation Method 1

amorphous phosphate of the compound of formula (I) is dissolved in ethanol, isopropyl alcohol or isoamyl alcohol, and solvent evaporation is performed to obtain a crystal form B

Methodology Applied
Scientific EffectSolvent evaporation: Evaporation

Implementation Method 2

the amorphous phosphate of the compound of formula (I) is dissolved in a mixed solvent of isoamyl alcohol and water or a mixed solvent of isopropyl alcohol and methyl tert-butyl ether, and a crystal seed of the crystal form B is added for induced crystallization to obtain the crystal form B

Methodology Applied
Scientific EffectCrystallization: Crystallisation

Implementation Method 3

its X-ray powder diffraction pattern has characteristic peaks at positions of which 2theta value is 15.2°±0.2°, 15.9°±0.2°, 19.2°±0.2° and 23.3°±0.2°

Methodology Applied
Scientific EffectX-ray diffraction: X-Ray

Data Source

PatentEP3785713B1Salt of cetagliptin, preparation method therefor, pharmaceutical composition, and use thereof
Publication Date: 2025.09.24 CGENETECH (SUZHOU CHINA) CO LTD
  • EP3785713B1 patent drawingFigure 1~2
  • EP3785713B1 patent drawingFigure 3~4
  • EP3785713B1 patent drawingFigure 5~6

AI summary

The present invention relates to a salt of a compound of formula (I), The salt is crystalline or amorphous phosphate, or crystalline or amorphous oxalate. Particularly, a crystal form B of the phosphate of the present invention has high crystallinity, low hygroscopicity and good stability, and the crystal form B of the phosphate is good in oral bioavailability, good in tolerance after long-term administration, difficult to induce hypoglycemia and good in inhibition effect on serum DPPIV.