Preservative-Free Tafluprost Eye Drops for Polyethylene Stability

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Solution Overview

Problem

Existing ophthalmic solutions containing PGF2α analogues face challenges with absorption to polyethylene containers, instability, and low solubility, especially in preservative-free formulations, which are necessary for patient safety.

Innovation Solution

Incorporation of nonionic surfactants and stabilizing agents in an aqueous ophthalmic solution, packaged in polyethylene containers, to prevent absorption and enhance solubility and stability of PGF2α analogues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If PGF2α analogues are formulated in preservative-free ophthalmic solutions, then patient safety is improved, but the solutions become unstable and the drug is absorbed to container walls

Engineering Contradiction:
Improvepatient safetyVSAvoidsolution stability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent introduces a surfactant as an intermediary substance that mediates between the lipophilic PGF2α analogue and the aqueous solution/container surface. The surfactant forms micelles that solubilize the drug and prevent its adsorption to polyethylene container walls, thereby maintaining solution stability in preservative-free formulations.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the physical-chemical parameters of the formulation by adjusting pH, ionic strength, and surfactant concentration to optimize drug solubility and stability. These parameter changes enable preservative-free formulations to remain stable by controlling the molecular interactions between the drug, surfactant, and container material.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If polyethylene containers are used for packaging, then flexibility and manufacturability are improved, but PGF2α analogues are absorbed to the container walls

Engineering Contradiction:
Improvecontainer manufacturabilityVSAvoiddrug absorption to container
Core Design Contradiction:
Ease of manufactureVSLoss of substance

Solution Approach 1:

The surfactant acts as a protective intermediary layer between the lipophilic PGF2α analogue and the polyethylene container surface. By forming micellar structures and modifying the container-drug interface, the surfactant prevents direct adsorption of the drug to the container walls, reducing drug loss while maintaining the benefits of polyethylene packaging.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Quantity of substance

If PGF2α analogue concentration is kept low for effective treatment, then ocular hypotensive effect is achieved, but the drug is more susceptible to absorption losses

Engineering Contradiction:
Improvedrug concentrationVSAvoiddrug stability in solution
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The surfactant serves as a protective intermediary that forms micellar structures around the low-concentration PGF2α analogue molecules. This micellar encapsulation prevents drug adsorption to container walls and maintains drug stability even at the low concentrations required for effective ocular hypotensive treatment.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution provides a stable, preservative-free ophthalmic formulation with improved solubility and bioavailability of PGF2α analogues, maintaining efficacy for treating ocular hypertension and glaucoma.

Implementation Method 1

absorption of tafluprost and other PGF2α analogues to the resinous container walls

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 2

as lipophilic substances PGF2α analogues such as tafluprost are liable to be absorbed

Methodology Applied
Scientific EffectSolubilization: Solvation

Data Source

PatentEP4512424B1Method and composition for treating ocular hypertension and glaucoma
Publication Date: 2026.03.18 SANTEN PHARMACEUTICAL CO LTD
  • EP4512424B1 patent drawingFigure 1~2
  • EP4512424B1 patent drawingFigure 3~4

AI summary

The present invention relates to a preservative-free prostaglandin eye drops for glaucoma patients for single use, wherein said preservative-free prostaglandin eye drops are filled in a container consisting essentially of low density polyethylene with 0.2-0.5 mL of solution containing 0.0010-0.0025% tafluprost as an active ingredient, 0.05-0.1% polysorbate 80 and 0.01-0.1% disodium edetate.