PVA–Cellulose Tablet Composition for Hardness and Sustained Release
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Solution Overview
Problem
Existing sustained-release tablets using polyvinyl alcohol (PVA) and microcrystalline cellulose do not achieve sufficient hardness, leading to rapid release of pharmaceutical ingredients if chewed or crushed, and fail to meet formulation standards for physical properties.
Innovation Solution
A composition comprising polyvinyl alcohol-based resin with specific particle size and viscosity, combined with crystalline cellulose, is used to create a tablet with increased hardness and sustained-release properties, suppressing initial release and ensuring 90% or more of the ingredient is released within 10 hours.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If PVA fine particles with gauche structure are used as binder to achieve sustained-release, then release rate is controlled, but tablet hardness is insufficient
Solution Approach 1:
The patent combines PVA fine particles with microcrystalline cellulose to create a composite matrix system. This composite approach allows the PVA to provide sustained-release through its gauche structure while microcrystalline cellulose contributes to tablet hardness and structural integrity, resolving the contradiction between sustained-release property and tablet strength
Solution Approach 2:
The patent specifies precise parameters for PVA including saponification degree (86-89 mol%), average polymerization degree (2200-3500), and particle size (30-100 μm). By controlling these parameters, the invention optimizes both the sustained-release characteristics and the mechanical properties of the tablet, achieving adequate hardness while maintaining controlled release
2Reliability
If tablet hardness is increased to prevent chewing, then sustained-release is maintained, but manufacturing complexity increases
Solution Approach 1:
The patent establishes specific parameter ranges for PVA (saponification degree 86-89 mol%, polymerization degree 2200-3500, particle size 30-100 μm) and microcrystalline cellulose (particle size 50-250 μm) to achieve the desired tablet hardness and sustained-release reliability. These controlled parameters ensure consistent performance while maintaining manufacturability
Solution Approach 2:
The PVA fine particles serve multiple functions: they act as a binder to hold the tablet together, provide sustained-release through their gauche structure, and contribute to the overall mechanical strength. This multi-functionality reduces the need for additional additives and simplifies the formulation
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 composition results in a tablet with high chewing difficulty and effective sustained-release properties, suitable for readily soluble pharmaceutical ingredients, meeting hardness and formulation standards while maintaining controlled release.
Implementation Method 1
the hydrogel formed from the PVA-based resin can suppress the release of the pharmaceutical ingredient
Implementation Method 2
The polyvinyl alcohol-based resin is water-soluble and biodegradable
Implementation Method 3
crystalline cellulose
Implementation Method 4
PVA-based resin is commonly used as an additive for a pharmaceutical tablet, particularly as a binder
Data Source
AI summary
The present invention provides a composition for a sustained-release tablet having such a high hardness to have chewing difficulty, and suppressing release of the pharmaceutical ingredient within a few hours after administration, but being able to release 90% or more of the pharmaceutical ingredient 10 hours after administration. The present invention also provides a tablet using the composition and a method for producing the tablet. The composition comprises a polyvinyl alcohol-based resin and crystalline cellulose, the polyvinyl alcohol-base resin having an average particle size of 100 µm or less and a viscosity of more than 44 mPa • s in 4% aqueous solution. The average particle size of the crystalline cellulose is preferably 250 µm or less, and either not greater than 0.5 times or not less than twice the size of the average particle size of the polyvinyl alcohol-based resin.