Liposomal Weak Acid Composition for Flatter Pulmonary Drug Levels

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Solution Overview

Problem

Existing inhalation therapies for pulmonary hypertension (PH) suffer from wide fluctuations in drug plasma levels, short half-lives, and frequent administration requirements, leading to systemic side effects and intolerance due to the use of prostaglandins and other weak acid drugs.

Innovation Solution

A pharmaceutical composition comprising liposomes with a specific lipid bilayer and internal aqueous medium, containing a weak acid drug and bicarbonate salt, which provides a pH gradient to achieve a peak to trough drug plasma concentration ratio (P/T ratio) of 1 to 100, allowing for reduced dosing frequency and enhanced potency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If inhaled prostaglandins are administered frequently (every 4 hours, 4-6 times a day), then therapeutic effect is maintained, but systemic side effects increase and patient intolerance occurs

Engineering Contradiction:
Improveduration of therapeutic effectVSAvoidsystemic side effects
Core Design Contradiction:
Duration of action of moving objectVSObject-affected harmful factors

Solution Approach 1:

The invention changes the physical-chemical parameters of the drug delivery system by formulating prostaglandins as liposomal encapsulated particles with specific size ranges (50-500 nm) and surface characteristics. This modification alters the pharmacokinetic parameters, extending half-life from less than 2 hours to at least 6 hours, enabling less frequent dosing while maintaining therapeutic effect and reducing side effects

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The liposome acts as an intermediary carrier between the prostaglandin drug and the biological system. The liposomal structure protects the drug, controls its release, and modifies its distribution pattern, allowing the drug to achieve prolonged circulation and reduced peak plasma concentrations that cause side effects

Inventive Principle:
Principle #24Intermediary (Mediator)

2Duration of action of moving object

If inhaled prostaglandins are administered frequently, then therapeutic effect is maintained, but administration frequency increases

Engineering Contradiction:
Improveduration of therapeutic effectVSAvoidtime spent on administration
Core Design Contradiction:
Duration of action of moving objectVSLoss of time

Solution Approach 1:

By modifying the drug delivery system to liposomal formulation, the pharmacokinetic parameter of half-life is extended from less than 2 hours to at least 6 hours. This parameter change directly reduces the number of administrations required per day from 4-6 times to 2 times, saving patient time and improving compliance

Inventive Principle:
Principle #35Parameter changes

3Reliability

If free weak acid drugs are used, then drug potency is lower, but formulation complexity increases when encapsulated in liposomes

Engineering Contradiction:
Improvedrug potencyVSAvoidformulation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention uses composite material structure where prostaglandin drugs are encapsulated within liposomal vesicles. The liposome consists of phospholipid bilayers with specific composition (phosphatidylcholine, phosphatidylglycerol, cholesterol, PEG-DSPE) forming a complex delivery system that enhances drug potency while the formulation process uses established liposomal preparation techniques

Inventive Principle:
Principle #40Composite materials

4Ease of operation

If inhaled prostaglandins are used, then direct delivery to target organ is achieved, but plasma concentration fluctuation increases

Engineering Contradiction:
Improvedirect delivery to target organVSAvoidplasma concentration stability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The liposomal formulation changes the release kinetics parameter of the drug, transforming it from rapid release (causing high peak plasma concentrations) to sustained release over at least 6 hours. This results in flatter plasma concentration profiles with reduced peak-to-trough variations while maintaining the inhaled route's advantage of direct pulmonary delivery

Inventive Principle:
Principle #35Parameter changes

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 composition maintains therapeutic effects for at least 6 hours with a flatter plasma profile, reducing administration frequency to 1-3 times daily and minimizing side effects while increasing drug potency by 2-15 times compared to free drugs.

Implementation Method 1

comprising a weak acid drug with a half-life less than 2 hours and a salt to provide a pH gradient between the internal aqueous medium and the external medium

Methodology Applied
Scientific EffectpH gradient:

Data Source

PatentEP3969002B1Pharmaceutical composition of a weak acid drug and methods of administration
Publication Date: 2026.04.22 PHARMOSA BIOPHARM INC
  • EP3969002B1 patent drawingFigure 1A~1C
  • EP3969002B1 patent drawingFigure 1D~1E
  • EP3969002B1 patent drawingFigure 2A~2C

AI summary

The present invention relates to a pharmaceutical composition containing liposomes, said liposome comprise an external lipid bilayer; and an internal aqueous medium including a weak acid drug with a half-life of less than 2 hours. Also provided is the use of the pharmaceutical composition disclosed herein to treat pulmonary hypertension with reduced dosing frequency.