Multilayered Enteric Hard Capsule Shell Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for creating enteric hard capsules are complex, prone to defects due to excessive coating, and difficult to apply to heat-sensitive contents, with the burden of complexity falling on the manufacturer filling the content rather than the hard capsule manufacturer.
Innovation Solution
A multilayered enteric hard capsule design featuring a first layer with no enteric properties and a second layer with enteric properties, where the second layer is formed using an enteric polymer and shell-forming aids, allowing for improved acid resistance and reduced complexity in the manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If spray coating method is used to create enteric hard capsules, then enteric properties are achieved, but the manufacturing process becomes complex and time-consuming
Solution Approach 1:
The enteric polymer is incorporated into the capsule shell formulation during the initial shell formation process, rather than applying it as a separate coating step afterward. This preliminary incorporation of the enteric layer into the shell manufacturing process eliminates the need for separate spray coating equipment and operations, thereby reducing manufacturing complexity while maintaining enteric properties
Solution Approach 2:
The shell formation process and enteric coating process are merged into a single integrated manufacturing step. By combining these two previously separate processes into one, the invention reduces the number of manufacturing stages, simplifies the overall process, and eliminates the need for separate spray coating equipment while ensuring uniform enteric properties throughout the capsule shell
2Manufacturing precision
If spray coating is performed for extended periods to ensure uniform enteric shell formation, then uniformity is improved, but productivity decreases
Solution Approach 1:
The enteric polymer is pre-mixed into the shell formulation before capsule formation, ensuring uniform distribution throughout the shell material. This preliminary uniform mixing eliminates the need for prolonged spray coating to achieve uniformity, as the enteric properties are inherently uniform from the start, thereby significantly improving manufacturing speed
Solution Approach 2:
The invention changes the fundamental parameter of how the enteric polymer is introduced - from a post-formed coating application to a pre-formed integral component. This parameter change allows the enteric shell to form uniformly during the standard capsule manufacturing cycle without requiring extended coating times, thus maintaining precision while boosting productivity
3Reliability
If enteric coating is applied after filling content into capsules, then enteric properties are achieved, but the filled capsules may adhere due to excessive coating solution
Solution Approach 1:
The enteric shell is formed as an integral part of the capsule shell before the filling operation. By establishing the enteric layer during shell manufacturing rather than as a post-fill coating, the invention eliminates the risk of excessive coating solution causing capsule adhesion, while still ensuring complete enteric coverage of the filled capsule
Solution Approach 2:
The capsule manufacturing process is segmented into distinct stages: shell formation with integrated enteric layer, then filling operation. This segmentation separates the enteric shell creation from the filling process, eliminating the problem of coating solution contact with filled capsules while maintaining the enteric functionality
4Ease of manufacture
If conventional polymers like gelatin are used as main component, then shell-forming ability is improved, but acid resistance is reduced
Solution Approach 1:
The capsule shell uses a composite formulation combining conventional shell-forming polymers (such as gelatin or HPMC) with enteric polymers (such as Eudragit or cellulose acetate phthalate). This composite structure leverages the excellent shell-forming properties of conventional polymers while the integrated enteric polymer component provides the necessary acid resistance, achieving both manufacturing ease and protective functionality
Solution Approach 2:
The shell formulation creates different functional zones: the conventional polymer provides the structural shell-forming matrix, while the enteric polymer creates a protective functional layer within the same shell structure. This local differentiation of material properties allows the shell to simultaneously exhibit good formability and acid resistance
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 multilayered design enhances acid resistance, reduces the risk of defective products, and simplifies the manufacturing process, allowing for the use of conventional capsule filling machines and improved stability of the enteric properties.
Implementation Method 1
the formulations are required to have such a level of acid-resistance that they are not substantially dissolved for two hours at 37°C in an acidic environment (pH about 1.2, diluted hydrochloric acid solution)
Implementation Method 2
the formulation has a characteristic of being easily dissolved after being transferred into the intestine
Implementation Method 3
a method in which the hard capsule filled with a content is spray-coated with an enteric polymer
Data Source
Figure 1
Figure 2(A)~2(C)
Figure 3(A)~3(B)
AI summary
A multilayered enteric hard capsule consisting of a first layer having no enteric properties and a second layer of a hard capsule having enteric properties is provided. The multilayered enteric hard capsule comprising a cap portion and a body portion, the cap portion and the body portion each consisting of a capsule shell comprising at least a first layer and a second layer in whole or in part, wherein the first layer contains a water-soluble base, the second layer contains an enteric polymer, and the second layer coats an outside of the first layer in whole or in part.