Sustained-Release Tablet Formulation Using Dual Viscosity Cellulose

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing sustained-release tablet formulations often fail to completely release drugs due to either incomplete elution or excessively rapid elution, which hinders achieving desired pharmacological effects.

Innovation Solution

A process involving dry granulation of a mixture containing hydroxyalkyl celluloses with different viscosities, along with an active ingredient and additives, to form tablets that inhibit initial drug release and ensure complete elution over time, using hydroxypropyl cellulose with specific viscosity ranges and particle sizes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If water-soluble polymers forming gel by contact with water are used as sustained-release preparations, then gel strength is improved and sustained-release effects are enhanced, but the drug may not completely elute from inside the preparation or elution speed may be too rapid

Engineering Contradiction:
Improvesustained-release effectsVSAvoiddrug elution control
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The invention uses a composite material system comprising HPMC and HPC in specific proportions (HPMC: 5.5-18% by mass, HPC: 5.5-18% by mass) to create a matrix that combines the gel-forming capability of HPMC with the structural reinforcement of HPC, achieving both gel strength and controlled drug elution

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention specifies precise viscosity ranges for HPMC (400-100,000 cps at 2% aqueous solution) and HPC (50-25,000 cps at 2% aqueous solution) to optimize the balance between gel formation and drug release kinetics, ensuring complete elution while maintaining sustained-release effects

Inventive Principle:
Principle #35Parameter changes

2Reliability

If high viscosity HPMC is used to enhance gel strength, then sustained-release properties are improved, but tablet hardness and mixture fluidity may be compromised

Engineering Contradiction:
Improvesustained-release propertiesVSAvoidtablet hardness
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The combination of HPMC and HPC creates a synergistic effect where HPC fine particles (at least 50% passing through 100 mesh screen) provide structural support and tablet hardness, while HPMC forms the gel matrix for sustained-release, resolving the contradiction between gel strength and tablet mechanical properties

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention assigns different functional roles to different components: HPC fine particles provide local structural reinforcement throughout the matrix, while HPMC provides the gel-forming continuous phase, creating localized functional zones that collectively achieve both sustained-release and mechanical strength

Inventive Principle:
Principle #3Local quality

3Reliability

If HPMC and HPC are used in the preparation, then gel strength is improved, but the complexity of formulation increases

Engineering Contradiction:
Improvegel strengthVSAvoidformulation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention establishes specific parameter ranges for HPMC viscosity (400-100,000 cps) and HPC viscosity (50-25,000 cps) that define the optimal formulation window, simplifying the formulation process by providing clear guidelines rather than requiring complex optimization experiments

Inventive Principle:
Principle #35Parameter changes

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

This method efficiently produces sustained-release tablets with superior sustained-release properties, inhibiting initial drug elution and allowing complete release after a prescribed time, while improving tablet hardness and mixture fluidity.

Implementation Method 1

water-soluble polymers that form a gel by contact with water were used as such sustained-release preparations

Methodology Applied
Scientific EffectGel formation: Gel

Implementation Method 2

inhibiting the initial elution of a drug and allowing the drug to be completely eluted after a prescribed amount of time has elapsed

Methodology Applied
Scientific EffectGel dissolution:

Data Source

PatentEP2005946B1Method for producing extended release tablet
Publication Date: 2015.11.18 NIPPON SODA CO LTD
  • EP2005946B1 patent drawingFigure 1~2
  • EP2005946B1 patent drawingFigure 3~4

AI summary

A process is provided for efficiently producing sustained-release tablets having superior sustained-release properties capable of inhibiting the initial elution of a drug and allowing the drug to be completely eluted after a prescribed amount of time has elapsed. A process for producing sustained-release tablets comprising: dry granulating a mixture composed of a hydroxyalkyl cellulose (A) having a viscosity of 1 to 50 mPa · s in a 2% by mass aqueous solution at 20°C, a Hydroxyalkyl cellulose (B) having a viscosity of 100 mPa · s or more in a 2% by mass aqueous solution at 20°C, an active ingredient and an additive, and forming the resulting granules into tablets.