Pullulan Capsule Shells via Vacuum Dip Molding
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Solution Overview
Problem
Conventional polysaccharide film compositions for hard shell capsules face issues such as breakage due to mechanical weakness, clumping from ultra-large molecules of pullulan powder, and inefficient manufacturing processes, leading to high production costs.
Innovation Solution
A dip molding process using a solution composed of pullulan polysaccharide with controlled molecular weight, neutrally charged hydrophilic amides, rheology modifiers, plasticizers, and chelating agents, filtered and cooled to remove air bubbles, then molded and dried to create strong, allergen-free hard capsule shells with improved mechanical strength and resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If ultra large molecules of pullulan powder are used in conventional polysaccharide film compositions, then the capsules can be manufactured, but mechanical weakness and clumping occur leading to breakage
Solution Approach 1:
The patent changes the molecular weight parameter of pullulan from ultra large molecules to a controlled range (100,000-800,000 Da), which fundamentally alters the film-forming properties and eliminates clumping while maintaining mechanical strength. This parameter change resolves the contradiction between manufacturability and mechanical reliability.
Solution Approach 2:
The patent creates a composite film formulation combining pullulan with specific plasticizers (glycerol, sorbitol), humectants, and optional additives that work synergistically to improve both mechanical strength and resistance to breakage, transforming a single-material limitation into a multi-component solution.
2Ease of manufacture
If conventional polysaccharide film compositions are used, then hard shell capsules can be produced, but spot mechanical weakness results from clumping
Solution Approach 1:
By controlling pullulan molecular weight and using filtered aqueous solutions, the patent eliminates the clumping that causes spot weakness, achieving uniform film formation that maintains both ease of manufacture and high manufacturing precision.
Solution Approach 2:
The patent applies preliminary filtration of the polysaccharide solution before dip molding to remove any potential clumps or impurities, ensuring uniform film formation from the outset and preventing manufacturing defects before they occur.
3Productivity
If conventional manufacturing processes are used for polysaccharide capsules, then production can proceed, but the process is inefficient leading to high production costs
Solution Approach 1:
The patent employs continuous dip molding where molds are repeatedly dipped into the polysaccharide solution without interruption, maintaining continuous film formation and drying cycles. This eliminates idle time between productions and significantly improves manufacturing efficiency while controlling costs.
Solution Approach 2:
The patent replaces complex mechanical capsule formation methods with a simpler dip molding process that uses fluid dynamics and controlled drying, reducing mechanical complexity and production costs while maintaining or improving productivity.
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 process reduces breakage and mechanical weakness, enhances manufacturing efficiency, and produces capsules with improved mechanical strength, resistance to cracking, and moisture retention, thereby reducing production costs and environmental impact.
Implementation Method 1
quickly remove the moisture from the air bubble free filtrate to a moisture induced setting point to transform the cooled reduced bubble free filtrate into a solid phase gel to form hard capsule shells
Implementation Method 2
vacuum the air bubble free filtrate
Data Source
AI summary
A dip molding process for the manufacture of allergen free hard capsule shells includes forming an allergen free solution, increasing the temperature of the allergen free solution, filtering the heated allergen free solution, vacuuming the filtrate to remove from 98 percent to 99 percent of air bubbles forming a reduced bubble filtrate, cooling the reduced bubble filtrate, dipping molding pins into the cooled filtrate, withdrawing the molding pins from the cooled filtrate, drying the molding pins with the cooled filtrate to form hard capsule shells, and coating the hard capsule shells with a vegetarian polishing agent. The formed vegan and allergen free hard capsules are dimensionally stable with a combination of (i) mechanical strength, (ii) resistance to cracking and (iii) resiliency. The created vegan and allergen free hard capsules have a body and cap that easily engage while producing an oxygen barrier for product.