Microneedle Patch Base Composition for Demolding and Adhesion
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Solution Overview
Problem
Conventional microneedle patches made from polyvinyl alcohol (PVA) face issues such as brittleness during drying, leading to breakage during demolding, poor skin adhesion, and high hygroscopicity, which complicates storage and reduces their effectiveness and longevity.
Innovation Solution
A base composition comprising a combination of first hydroxypropyl methylcellulose (HPMC), second HPMC, and polyvinylpyrrolidone/vinyl acetate copolymer (PVP/VA) is used, which provides improved mechanical strength, softness, flexibility, and skin adhesion, while reducing hygroscopicity and enhancing storage stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If polyvinyl alcohol (PVA) is used as the base material for microneedle patches, then good film-forming property and mechanical strength are achieved, but brittleness during drying occurs leading to breakage during demolding
Solution Approach 1:
The patent replaces the single-material PVA base with a composite formulation consisting of multiple polymers (including polyvinylpyrrolidone, carboxymethyl cellulose, and hydroxypropyl methylcellulose) in specific ratios. This composite material system provides both the required mechanical strength and flexibility to prevent brittleness and breakage during demolding, while maintaining film-forming properties.
Solution Approach 2:
The patent modifies the chemical composition parameters of the base material by specifying precise weight ratios of different polymer components (e.g., polyvinylpyrrolidone 5-15%, carboxymethyl cellulose 10-20%, hydroxypropyl methylcellulose 5-15%). These parameter changes optimize the balance between mechanical strength and flexibility, preventing brittleness during the drying process.
2Strength
If polyvinyl alcohol (PVA) is used as the base material for microneedle patches, then mechanical strength is achieved, but poor skin adhesion occurs
Solution Approach 1:
The composite polymer base combines materials with complementary properties: polyvinylpyrrolidone provides adhesion enhancement, carboxymethyl cellulose contributes to skin compatibility, and hydroxypropyl methylcellulose provides structural support. This composite system achieves both mechanical strength and improved skin adhesion simultaneously.
3Stability of the object's composition
If polyvinyl alcohol (PVA) is used as the base material for microneedle patches, then film-forming property is achieved, but high hygroscopicity occurs leading to difficulty in storage and short storage time
Solution Approach 1:
The composite polymer system incorporates polymers with lower hygroscopicity (such as hydroxypropyl methylcellulose and carboxymethyl cellulose) to counterbalance the hygroscopic nature of PVA. This composite formulation reduces overall moisture absorption while preserving the necessary film-forming capabilities, thereby extending storage time and improving storage stability.
Solution Approach 2:
The patent adjusts the formulation parameters by limiting PVA content and introducing polymers with different hygroscopic characteristics. The specific weight ratios of the composite polymers are optimized to reduce water absorption while maintaining film integrity, directly addressing the storage stability issue.
4Strength
If the degree of drying is increased to prevent breakage during demolding, then mechanical strength is improved, but skin adhesion deteriorates
Solution Approach 1:
The composite polymer base provides inherent flexibility that allows the microneedle patch to achieve sufficient mechanical strength without requiring excessive drying. The polymer combination maintains adequate moisture content for skin adhesion while preventing breakage, eliminating the need to increase drying degree.
Data Source
AI summary
The present invention relates to a base composition for a microneedle patch and a microneedle patch comprising the same. The base composition comprises a first HPMC, a second HPMC and PVP/VA, wherein the viscosity of the first HPMC is greater than that of the second HPMC, the weight ratio of the first HPMC relative to the second HPMC is 1:0.1 to 1: 1.2, and the amount of the PVP/VA is 0.25 wt% to 2 wt%. By controlling the constitution of the base composition, the microneedle patch can not only be demolded smoothly during the stage of the production, but also obtain the desired softness, flatness, flexibility, skin adhesion during the stage of use and humidity resistance during the stage of storage.