Aerosol Foam Emulsifier Blend for Low Solubility API Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Formulating stable aerosol foams with low water solubility active pharmaceutical ingredients (APIs) is challenging due to issues like incomplete propellant mixing, foam instability, and reduced bioavailability, leading to inconsistent drug delivery and potential clogging of valves.
Innovation Solution
An aerosol foam composition using a propellant blend of liquefied hydrocarbon gases, such as propane, isobutane, and butane, combined with an emulsifier blend of cetearyl alcohol, dicetyl phosphate, and ceteareth-10 phosphate, which stabilizes the foam and ensures consistent delivery of low water solubility APIs without degrading them during storage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional surfactants are used in aerosol foam formulations with low water solubility APIs, then the foam can be formed, but the foam stability is poor and the API delivery is inconsistent
Solution Approach 1:
The patent uses a composite surfactant system comprising both ionic (dicetyl phosphate) and nonionic (ceteareth-10 phosphate) surfactants in specific proportions (0.1-5% ionic, 0.1-2% nonionic). This composite approach creates synergistic effects that enhance foam stability while ensuring consistent API delivery, resolving the contradiction between foam stability and delivery precision.
Solution Approach 2:
The patent optimizes specific formulation parameters including surfactant concentration ratios, propellant-to-concentrate ratios (0.25:1 to 1:1), and pH levels (5.0-7.0). These parameter adjustments create a balanced formulation that achieves both stable foam structure and consistent low water solubility API delivery throughout the product lifecycle.
2Ease of operation
If propellant is added to achieve foam expansion, then the foam can be dispensed, but incomplete mixing occurs and valve clogging happens
Solution Approach 1:
The patent incorporates mixing instructions in the shaking protocol before actuation, and formulates the concentrate with viscosity modifiers and surfactants that pre-condition the mixture for homogeneous propellant distribution. This preliminary action prevents incomplete mixing and valve clogging while maintaining ease of dispensing.
Solution Approach 2:
The surfactant blend acts as an intermediary that facilitates uniform distribution of the propellant throughout the concentrate. The specific combination of ionic and nonionic surfactants reduces surface tension and promotes homogeneous mixing, preventing propellant separation and valve clogging during dispensing.
3Duration of action of stationary object
If storage time is extended to ensure treatment duration, then patient compliance improves, but API degradation occurs
Solution Approach 1:
The patent uses hydrocarbon propellants (propane, isobutane, butane) that create an inert atmosphere within the aerosol can, protecting the low water solubility API from oxidation and degradation during extended storage. The surfactant system also maintains a stable chemical environment that preserves API integrity throughout the product shelf life.
Solution Approach 2:
The patent employs stabilizers and antioxidants in the formulation that provide short-term protection during storage, ensuring API stability throughout the intended shelf life. These protective agents are consumed over time, and the formulation is designed to maintain effectiveness throughout the disposable product lifecycle.
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 results in a stable, aesthetically pleasing foam with consistent physical properties and no discernable API degradation, ensuring effective and prolonged delivery of low water solubility APIs, improving patient compliance and treatment efficacy.
Implementation Method 1
When an aerosol foam formulation is discharged from the container, the liquid propellant volatilizes producing a semi-solid foam product that is expanded with gas phase propellant
Implementation Method 2
an emulsifier blend of cetearyl alcohol, dicetyl phosphate and ceteareth-10 phosphate
Implementation Method 3
The surfactants concentrate at the interface between the propellant/oil phase and the aqueous phase to form a thin film referred to as the 'lamella'
Implementation Method 4
It is the specific composition of this lamella that dictates the structural strength and general characteristics of the foam that forms when the liquid propellant in the internal phase transitions into a gas
Data Source
AI summary
The present invention is directed to an aerosol foam composition comprising an active pharmaceutical ingredient (API) with low water solubility an emulsifier blend containing cetearyl alcohol, dicetyl phosphate, and ceteareth-10 phosphate and a hydrocarbon propellant. The aerosol foam composition is preferably an oil in water emulsion. The propellant is a mixture of liquefied hydrocarbon gases preferably a propane/isobutane/butane blend. The hydrocarbon propellant results in an aerosol foam which is stable, has consistent physical properties, excellent aesthetics, and no discernable API degradation after long term or accelerated storage conditions.