Amorphous Citrate Salt Formulation for Parkinson's Bioavailability

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Solution Overview

Problem

Current treatments for Parkinson's disease, such as L-Dopa therapy, often lead to severe motor complications like dyskinesia and 'wearing-off' due to long-term use, and proton pump inhibitors impair the bioavailability of A2A receptor antagonists like the compound of Formula I, necessitating a formulation that can coadminister with these medications without reducing safety margins or increasing variability.

Innovation Solution

A formulation comprising a dispersion of the compound of Formula I as an amorphous citrate salt in a water-soluble matrix polymer, combined with citric acid and solubilizing agents, which maintains bioavailability by neutralizing the effects of proton pump inhibitors and is suitable for oral administration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the compound of Formula I is administered orally in a standard formulation, then it can be conveniently administered to patients, but the bioavailability is significantly reduced when coadministered with proton pump inhibitors due to low acid environment

Engineering Contradiction:
Improveconvenience of oral administrationVSAvoidbioavailability consistency
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent converts the compound of Formula I into its citrate salt form, changing the chemical parameter of the drug molecule. This salt form has improved solubility and stability in the low-acid environment created by proton pump inhibitors, thereby maintaining consistent bioavailability regardless of coadministration with these medications

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces citric acid as an intermediary substance in the formulation. This intermediary acts as a pH buffer that maintains an acidic microenvironment in the gastrointestinal tract, protecting the compound of Formula I from the alkaline conditions created by proton pump inhibitors and ensuring consistent absorption

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If proton pump inhibitors are administered to manage gastric disorders in Parkinson's disease patients, then gastric symptoms are relieved, but the bioavailability of A2A receptor antagonists is impaired

Engineering Contradiction:
Improvegastric disorder reliefVSAvoiddrug bioavailability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The formulation includes citric acid and other acidifying agents that act as intermediaries to maintain gastric acidity. These substances buffer the pH environment, ensuring that even when proton pump inhibitors are present, the local acid environment necessary for optimal absorption of the A2A antagonist is maintained

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent incorporates acidifying agents and citrate salts in advance within the formulation design. This beforehand cushioning creates a protective acidic environment that anticipates and counteracts the alkaline effect of proton pump inhibitors, ensuring consistent drug absorption despite the presence of these gastric medications

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If long-term L-Dopa therapy is used to treat Parkinson's disease, then motor symptoms are alleviated, but severe motor complications such as dyskinesia and wearing-off effects occur

Engineering Contradiction:
Improvemotor symptom controlVSAvoidmotor complications
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent targets and blocks the adenosine A2A receptors in the striatum, which are involved in the pathophysiology of Parkinson's disease. By selectively antagonizing these receptors, the formulation provides an alternative therapeutic pathway that does not involve dopamine replacement, thereby avoiding the motor complications associated with long-term L-Dopa therapy while still achieving motor symptom control

Inventive Principle:
Principle #2Taking out (Extraction)

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 formulation effectively mitigates the bioavailability reduction caused by proton pump inhibitors, ensuring consistent and safe delivery of the A2A antagonist, reducing motor symptoms in Parkinson's disease while minimizing adverse effects.

Implementation Method 1

a dispersion comprising: (i) a water soluble matrix polymer; (ii) a compound of Formula I, and (iii) citric acid, wherein, at least about 70 mole% of said compound of Formula I is present in the dispersion in the form of a citrate salt

Methodology Applied
Scientific EffectAmorphous state stabilization:

Implementation Method 2

a mixture of at least one acidifying agent and at least one solubilizing agent

Methodology Applied
Scientific EffectpH modulation:

Data Source

PatentEP3227299B1Formulation inhibiting effects of low acid environment
Publication Date: 2021.05.26 MERCK SHARP & DOHME CORP
  • EP3227299B1 patent drawingFigure 1
  • EP3227299B1 patent drawingFigure 2
  • EP3227299B1 patent drawingFigure 3

AI summary

The present invention is directed to formulations comprising PVP polymer, a dispersion of a compound of Formula I (API):, and citric acid, which formulations mitigate the effects of coadministering the compound of Formula I with a proton pump inhibitor compound.