Anionic Emulsion Stabilizing Prostaglandins Without Cationic Agents

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Solution Overview

Problem

Prostaglandins, such as latanoprost, are chemically unstable due to sensitivity to light and heat, and cationic emulsions can cause corneal and conjunctival lesions in some patients, necessitating a stable and non-cationic formulation for ophthalmic use.

Innovation Solution

An anionic oil-in-water emulsion comprising prostaglandin F 2alpha, a non-ionic surfactant that releases negative charges, and a saturated oil, with a negative zeta potential, which is free of cationic agents and polyvinyl alcohol, enhancing chemical stability and tolerability for patients with eye surface lesions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If cationic emulsions are used to stabilize prostaglandins, then chemical stability is improved, but corneal and conjunctival lesions occur in some patients

Engineering Contradiction:

Improvechemical stabilityVSAvoidcorneal and conjunctival lesions

Core Design Contradiction:

Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

Instead of using cationic surfactants to stabilize the emulsion, the invention inverts the approach by using non-ionic surfactants that spontaneously form anionic emulsions. This inversion eliminates the harmful cationic成分 while maintaining stabilization functionality through the negative zeta potential generated by the non-ionic surfactant system.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The non-ionic surfactant acts as an intermediary that generates negative charges during the manufacturing process, enabling the formation of a stable anionic emulsion without requiring cationic agents. The surfactant mediates between the need for stability and the need to avoid corneal and conjunctival lesions.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If prostaglandins are formulated in conventional solutions, then ease of administration is maintained, but chemical stability deteriorates due to sensitivity to light and heat

Engineering Contradiction:

Improveease of administrationVSAvoidchemical stability

Core Design Contradiction:

Ease of operationVSStability of the object's composition

Solution Approach 1:

The invention changes the physical state and formulation parameters by transitioning from conventional aqueous solutions to an oil-in-water emulsion system with specific particle size distribution (0.1-10 μm) and controlled negative zeta potential. This parameter change provides protection against light and heat while maintaining ease of topical administration.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite emulsion system combining prostaglandins, non-ionic surfactants, and oil phases with specific properties. This composite formulation provides enhanced chemical stability through the synergistic interaction of components while maintaining the desired ease of administration characteristics.

Inventive Principle:

Principle #40Composite materials

3Object-affected harmful factors

If non-ionic surfactants are used to avoid cationic ingredients, then tolerability is improved, but emulsion stability may be compromised

Engineering Contradiction:

ImprovetolerabilityVSAvoidemulsion stability

Core Design Contradiction:

Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The non-ionic surfactant system performs self-service by spontaneously generating negative charges during the manufacturing process without requiring additional cationic additives. The system self-regulates to achieve the desired anionic character and stable emulsion formation, eliminating the need for complex multi-component formulations.

Inventive Principle:

Principle #25Self-service

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 anionic emulsion provides improved stability and tolerability, maintaining prostaglandin efficacy while avoiding adverse reactions, and remains physically stable and effective under stress testing conditions.

Implementation Method 1

the non-ionic surfactant releases negative charges during the manufacturing process

Methodology Applied

Scientific EffectCharge release:

Implementation Method 2

emulsions were a suitable vehicle to stabilize prostaglandins

Methodology Applied

Scientific EffectEmulsification: Emulsion

Implementation Method 3

an anionic oil-in-water emulsion comprising prostaglandin F 2alpha, a non-ionic surfactant that releases negative charges, and a saturated oil

Methodology Applied

Scientific EffectDissolution: Solvation

Data Source

PatentEP2403478B1Anionic oil-in-water emulsions containing prostaglandins and uses thereof

Publication Date: 2016.03.02 SANTEN SAS

Figure 1

AI summary

The present invention relates to a colloidal anionic oil-in-water emulsion comprising a prostaglandin, an oil having a iodine value = 2, a surfactant and water, provided the anionic oil-in-water emulsion does not contain polyvinyl alcohol. The present invention also pertains to the use of said anionic oil-in-water emulsions for enhancing the stability of said prostaglandins, for the treatment of ocular hypertension and/or glaucoma, for promoting growth of eyelashes and/or for treating eyelash hypotrichosis.