Polyether Copolymer Matrix for Amorphous Drug Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current pharmaceutical formulations of slightly water-soluble active substances face challenges in achieving stable solid solutions, maintaining bioavailability, and controlling the release of the active substance, as they often result in crystallization and variable release rates due to the properties of the active substance, such as particle size and crystal modification.
Innovation Solution
The development of pharmaceutical dosage forms using polyether copolymers obtained by free radical polymerization of N-vinyllactam, vinyl acetate, and polyether, combined with slightly water-soluble polymers, which embed the active substance in an amorphous form within a polymer matrix, allowing for controlled release and improved stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polyether copolymers are used as solubilizers for slightly water-soluble active substances, then solubility and bioavailability are improved, but the active substance may crystallize during storage, reducing stability
Solution Approach 1:
The patent combines polyether copolymers with poorly water-soluble polymers to create a composite matrix system. This composite structure prevents crystallization of the active substance while maintaining solubility enhancement, resolving the contradiction between improved solubility and long-term stability.
Solution Approach 2:
The patent modifies the physical state parameter of the active substance by embedding it in an amorphous form within the polymer matrix. This parameter change from crystalline to amorphous state prevents crystallization during storage while maintaining the solubilization effect.
2Quantity of substance
If the active substance is present above saturated concentration in the polymer, then solubilization capacity is improved, but the system becomes kinetically controlled and the active substance crystallizes during storage
Solution Approach 1:
The composite matrix of polyether copolymer and poorly water-soluble polymer creates a more robust structure that can accommodate higher active substance concentrations while preventing crystallization through the amorphous state maintained by the polymer network.
Solution Approach 2:
The patent creates local amorphous regions within the polymer matrix where the active substance is embedded. These local zones with specific molecular arrangement prevent crystallization even at high concentrations, allowing increased active substance content without sacrificing stability.
3Reliability
If known polymeric solubilizers are used, then solubilization is achieved, but they do not form stable solid solutions and the active substance crystallizes during storage
Solution Approach 1:
The patent creates a composite system combining polyether copolymers with poorly water-soluble polymers. This composite structure provides both solubilization capability and solid solution stability, preventing crystallization during storage unlike single-polymer systems.
Solution Approach 2:
The poorly water-soluble polymer acts as an intermediary that stabilizes the amorphous state of the active substance within the polyether copolymer matrix. This intermediary polymer prevents the crystallization tendency that occurs with polyether copolymers alone.
4Reliability
If solubilizers with high hygroscopicity are used to improve solubility, then solubilization is enhanced, but deliquescence and crystallization of the active substance occur
Solution Approach 1:
The composite matrix of polyether copolymer and poorly water-soluble polymer creates a structure with balanced hygroscopicity. The poorly water-soluble polymer component reduces the overall water uptake tendency while maintaining the solubilization effect, preventing deliquescence.
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 approach results in stable, amorphous formulations with enhanced bioavailability and controlled release profiles, maintaining the active substance in a molecularly disperse state and preventing crystallization, thereby ensuring consistent release properties over time.
Implementation Method 1
Solubilization is to be understood as meaning the imparting of solubility to substances which are slightly soluble or insoluble in a certain solvent, in particular water, by surface-active compounds, the solubilizers. Such solubilizers are capable of converting poorly water-soluble or water-insoluble substances into transparent, at most opalescent aqueous solutions
Implementation Method 2
The term 'solid solution' designates a state in which a substance is dispersed in colloidal form or ideally dispersed in molecular form in a solid matrix, for example a polymer matrix
Implementation Method 3
polyether copolymers being obtained by free radical polymerization of N-vinyllactam, vinyl acetate, and polyether
Data Source
AI summary
Dosage forms comprising preparations of slightly water-soluble active substances in a polymer matrix of polyether copolymers, the polyether copolymers being obtained by free radical polymerization of a mixture of from 30 to 80% by weight of N-vinyllactam, from 10 to 50% by weight of vinyl acetate and from 10 to 50% by weight of a polyether, and of at least one slightly water-soluble polymer in which the slightly water-soluble active substance is present in amorphous form in the polymer matrix.