Microemulsion Formulation with Non-Surfactant Amphiphilic Compounds
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Formulating microemulsions and sub-micron emulsions for dermal delivery of pharmaceutically active ingredients is challenging due to issues like instability, skin irritation, and difficulty in incorporating substances like propylene glycol and petrolatum, which affect viscosity, appearance, and efficacy.
Innovation Solution
A process involving the stepwise mixing of oil and water phases with specific temperature control and the inclusion of a third part containing non-surfactant amphiphilic compounds to achieve phase assembly at a lower temperature, ensuring stability and optimal delivery of active ingredients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional emulsification methods are used to formulate microemulsions, then emulsion formation is achieved, but the formulation becomes unstable and loses microemulsion characteristics
Solution Approach 1:
The disruptive substance is incorporated into the oil phase before emulsification occurs, allowing it to be pre-positioned within the emulsion droplets. This preliminary incorporation prevents the substance from disrupting the microemulsion structure during and after formation, while still allowing it to provide its intended function (such as penetration enhancement) once the emulsion is applied to the skin.
Solution Approach 2:
The formulation is divided into distinct phases (oil phase containing the disruptive substance, water phase, and surfactant system) that are combined in a specific sequence. By segmenting the incorporation steps and controlling which phase receives the disruptive substance, the patent prevents direct interaction between the disruptive substance and the microemulsion structure during formation.
2Object-affected harmful factors
If disruptive substances like propylene glycol are added to microemulsions, then penetration enhancement is improved, but the microemulsion structure is disrupted and stability is lost
Solution Approach 1:
The oil phase acts as an intermediary vehicle that carries the disruptive substance to the emulsion droplets. By using this intermediate carrier phase, the disruptive substance is delivered to the intended location (within the emulsion structure) without directly interfering with the emulsification process or the microemulsion formation mechanism.
3Object-affected harmful factors
If petrolatum is incorporated into microemulsions, then occlusive properties and emollience are improved, but viscosity and appearance are adversely affected
Solution Approach 1:
Petrolatum is placed specifically in the oil phase rather than being distributed throughout the entire microemulsion system. This localized placement allows petrolatum to provide occlusive and emollient benefits where needed (in the oil droplets) while preventing it from interfering with the overall microemulsion viscosity and appearance characteristics.
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
This method allows for the stable formulation and delivery of insoluble active ingredients, such as corticosteroids, across the skin barrier, enhancing transdermal delivery and maintaining formulation stability and efficacy.
Implementation Method 1
heating the mix of step a) to a phase assembly temperature in the range of 40-99°C, preferably 45-95°C, more preferably 65-85°C with continuous mixing to obtain an oil in water microemulsion or sub-micron emulsion
Implementation Method 2
a process for the preparation of an oil in water (O/W) microemulsion or sub-micron emulsion composition for dermal delivery
Implementation Method 3
heating the mix of step a) to a phase assembly temperature in the range of 40-99°C, preferably 45-95°C, more preferably 65-85°C with continuous mixing
Implementation Method 4
allowing said microemulsion or sub-micron emulsion to cool
Data Source
AI summary
An oil-in-water microemulsion or sub-micron emulsion composition for dermal delivery of at least one pharmaceutically active ingredient, comprising: a first part including at least one occlusive agent and one or more lipophilic surfactants dispersed throughout a second part including water and at least one hydrophilic surfactant, and a non-surfactant amphiphilic type compound, pharmaceutically active ingredient, and water. It has been found that if a non-surfactant amphiphilic type compound is added together with the second part as would conventionally be the case, a microemulsion or sub-micron emulsion is not formed, by adding the so called third part, phase assembly occurs at a lower temperature than would be expected and moreover, this phase appears to assist in maintaining the microemulsion or sub-micron emulsion characteristics of the formulation during storage at normal temperatures.