Drug-Ion Exchange Resin Coating Swelling Control
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Solution Overview
Problem
Current pharmaceutical preparations using drug-ion exchange resin complexes face challenges with short drug release duration, premature rupture of diffusion barrier coatings due to swelling, and the need for solvent-based coatings, which are hazardous and require complex processing steps, limiting the availability of sustained release products, especially for fine particles.
Innovation Solution
Development of a pharmaceutical composition involving a drug-ion exchange resin complex admixed with a water-insoluble polymer and coated with a highly flexible, non-ionic, water-permeable diffusion barrier that maintains film integrity, providing prolonged and programmable release of up to 24 hours without using organic solvents or standard polymers, and reducing the risk of coating rupture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If a water-permeable diffusion barrier coating is applied to drug-ion exchange resin complexes, then drug release duration is extended, but the coating layer fractures and ruptures due to swelling of the resin complex
Solution Approach 1:
The patent introduces an impregnating agent as an intermediary substance that penetrates into the resin complex matrix before coating application. This agent reduces the swelling tendency of the resin complex when exposed to water, thereby preventing coating fracture while maintaining the extended drug release function. The impregnating agent acts as a mediator between the resin complex and the coating layer, resolving the contradiction between coating integrity and drug release duration.
Solution Approach 2:
The patent modifies the physical-chemical parameters of the resin complex by treating it with impregnating agents that alter its swelling characteristics. This parameter change (reducing swelling) allows the coating layer to remain intact while still permitting controlled drug release over extended periods, thus resolving the contradiction between coating reliability and release duration.
2Duration of action of stationary object
If solvent-based coating systems are used to coat drug-ion exchange resin complexes, then sustained release is achieved, but hazardous solvents must be removed and complex processing steps are required
Solution Approach 1:
The patent changes the fundamental parameter of the coating system from solvent-based to water-based. This parameter change eliminates the need for hazardous solvent removal steps and simplifies the manufacturing process while maintaining the sustained release function through the water-permeable diffusion barrier coating.
Solution Approach 2:
The patent substitutes the solvent-based coating mechanism with a water-based coating system. This substitution replaces the need for complex solvent evaporation and removal processes with a simpler water-based application method that achieves the same sustained release effect without hazardous materials or complex processing.
3Quantity of substance
If fine particles of drug-ion exchange complexes are used, then drug loading is increased, but coating application becomes difficult and sustained release products are limited
Solution Approach 1:
The patent applies preliminary treatment to the fine particles by impregnating them with swelling-reducing agents before coating application. This preliminary action modifies the particle properties to make them more amenable to coating, allowing fine particles with high drug loading to be successfully coated with water-permeable diffusion barriers to achieve sustained release.
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 solution enables a sustained release of drugs from drug-ion exchange resin complexes for up to 24 hours, improving drug binding efficiency, reducing the need for enteric coatings, and enhancing processing benefits, while minimizing undesirable taste and agglomeration issues, thus providing a more effective and stable drug delivery system.
Implementation Method 1
Use of ion-exchange resins to form a drug-ion exchange resin complex is well known and is described, for example, in U.S. Pat. No. 2,990,332. In this patent, the use of an ion-exchange resin to form a complex with ionic drugs and thereby delay the drug release from such complexes is described.
Implementation Method 2
there have been additional publications and patents (e.g., U.S. Pat. Nos. 3,138,525; 3,499,960; 3,594,470; Belgian Patent No. 729,827; German Patent No. 2,246,037) that describe use of such ion-exchange resin complexes with water-permeable diffusion barrier coatings of the drug-ion exchange resin complex coated to alter the release of drugs from the drug-ion exchange resin complex.
Implementation Method 3
Raghunathan in U.S. Pat. Nos. 4,221,778; 4,847,077 and Raghunathan et al. in J. Pharm. Sci., Vol 70, pp 379-384, April 1981, describe treating drug-ion exchange resin complexes with water soluble, hydrophilic impregnating (solvating) agents such as polyethylene glycol and others so as to enable the coating of drug-ion exchange resin complexes with a water-permeable diffusion barrier.
Data Source
AI summary
An aqueous liquid suspension containing a coated drug-ion exchange resin complex comprising a core composed of an amphetamine complexed with a pharmaceutically acceptable ion-exchange resin and an uncoated amphetamine-ion exchange resin complex is provided. The coated amphetamine-ion exchange resin complex is in admixture with a polymer to form a matrix. Methods of making the coated complex and the liquid suspension are described.