Silk-Based Capsule Shell Interpenetrating Network
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Solution Overview
Problem
Existing hard and soft capsules are not compatible with all pharmaceutical formulations, particularly those requiring self-emulsifying or self-microemulsifying drug delivery systems, and face issues with high hydrophilic-lipophilic balance surfactants and controlled release formulations, leading to fill leakage and stability problems.
Innovation Solution
Development of silk-based hard and soft capsules using a solubilized silk polymer and a film-forming polymer, which form an interpenetrating network (IPN) to enhance stability and control release, incorporating additives like plasticizers and enteric polymers for improved compatibility and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If existing soft capsule shells are used with high-HLB-value surfactants, then the capsule can accommodate self-emulsifying or self-microemulsifying drug delivery systems, but the seams of soft capsules are weakened resulting in fill leakage over time
Solution Approach 1:
The patent modifies the chemical composition parameters of the capsule shell by incorporating specific polymers (gelatin, glyceryl monostearate, and titanium dioxide) in controlled proportions. This compositional parameter change enables the shell to accommodate high-HLB surfactants while maintaining seam integrity, resolving the contradiction between formulation compatibility and reliability.
2Duration of action of moving object
If existing soft capsules are used for controlled release formulations with high melting point waxes, then the desired sustained release profile can be achieved, but the viscosity of the gel mass becomes too low above a narrow temperature range preventing reliable capsule formation
Solution Approach 1:
The patent expands the acceptable temperature range for capsule formation by modifying the gel mass composition. The specific polymer blend maintains appropriate viscosity across a broader temperature range, allowing controlled release formulations to be manufactured reliably while preserving the sustained release characteristics.
3Object-affected harmful factors
If enteric coating is applied to conventional hard and soft capsules, then protection from gastric conditions can be achieved, but the capsule shell undergoes thermally induced agglomeration and distortion during coating
Solution Approach 1:
The patent incorporates enteric polymer directly into the capsule shell formulation during manufacturing, rather than applying it as a post-manufacturing coating. This beforehand integration prevents thermal stress during separate coating operations, eliminating agglomeration and distortion while maintaining the protective enteric function against gastric conditions.
4Object-affected harmful factors
If enteric coating is applied to conventional capsules, then gastric protection can be achieved, but the smoothness and elasticity of the capsule surface makes it difficult to form an intact adhering coating
Solution Approach 1:
The patent merges the enteric protective function with the capsule shell structure itself by incorporating enteric polymer into the shell formulation. This consolidation eliminates the need for separate coating processes, simplifying manufacturing while maintaining gastric protection. The shell itself becomes the protective barrier rather than requiring an additional coating layer.
5Object-affected harmful factors
If enteric coating is applied to conventional capsules, then gastric protection can be achieved, but the normally shiny and clear appearance of capsule shells is lost
Solution Approach 1:
The patent combines the enteric protective function with the capsule shell in a single integrated structure. By incorporating enteric polymer into the shell formulation rather than applying an external coating, the natural shiny and clear appearance of the capsule shell is preserved while maintaining gastric protection functionality.
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 silk-based capsules exhibit improved stability, robust seams, and controlled release properties, addressing compatibility issues with various pharmaceutical formulations and maintaining fill integrity under different storage conditions.
Implementation Method 1
Development of silk-based hard and soft capsules using a solubilized silk polymer and a film-forming polymer, which form an interpenetrating network (IPN) to enhance stability and control release
Data Source
AI summary
A hard or soft capsule is disclosed comprising a shell and a fill material, wherein the shell comprises an interpenetrating network comprising a silk polymer and a film-forming natural polymer. A method of making a hard or soft capsule is also disclosed, comprising dissolving a silk protein in a solvent system to form a solubilized silk protein solution; mixing the solubilized silk protein solution with a film-forming natural polymer to form a homogenous shell material; and encapsulating a fill material with the homogenous shell material.