Sustained Release Dosage Form Using pH-Dependent and Independent Retardants
Solution Overview
Problem
Existing sustained release dosage forms face challenges in achieving pH-independent drug release profiles for drugs with high aqueous solubility, as they often result in variable bioavailability due to pH-dependent release mechanisms and swelling issues, which are complex and costly to manufacture.
Innovation Solution
A combination of non-swelling pH-dependent and pH-independent release retardants is used to create a sustained release dosage form that provides pH-independent drug release for a considerable period, minimizing swelling and variability in gastrointestinal transit profiles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If a pH-dependent polymer is used to control drug release, then release can be modulated in different pH environments, but the release profile becomes variable and dependent on physiological pH conditions
Solution Approach 1:
The patent combines a pH-dependent polymer (Eudragit L100) with a pH-independent swelling polymer (Kolidon SR) to create a composite matrix system. The pH-dependent polymer provides initial drug release control while the pH-independent polymer maintains structural integrity and provides sustained release through swelling, achieving both prolonged duration and reproducible release profiles across different pH conditions.
Solution Approach 2:
The formulation uses a composite matrix comprising Eudragit L100 (pH-dependent) and Kolidon SR (pH-independent) in specific ratios. This composite material leverages the complementary properties of both polymers: the pH-dependent polymer responds to environmental pH changes while the pH-independent polymer provides consistent swelling behavior, resulting in reliable and reproducible drug release profiles.
2Duration of action of moving object
If a swelling hydrophilic polymer is used to retard drug release, then release can be extended over time, but the dosage form exhibits high variability in gastrointestinal transit profile
Solution Approach 1:
The patent applies local quality by assigning different functional roles to different components of the matrix: Eudragit L100 provides localized pH-dependent release control at the matrix surface, while Kolidon SR provides localized swelling and structural support throughout the matrix. This spatial differentiation of functions allows the system to achieve extended release while maintaining consistent physical properties and transit behavior.
3Reliability
If a compact inert core with polymeric membrane is used for controlled release, then pH-independent release profile can be achieved, but the manufacturing process becomes complicated and expensive
Solution Approach 1:
The patent extracts the complex multi-step coating process of prior art and replaces it with a simplified single-step compression process. By formulating a direct-compression matrix tablet using a blend of Eudragit L100 and Kolidon SR, the invention eliminates the need for separate core formation, membrane coating, and solvent evaporation steps, achieving pH-independent release with significantly reduced manufacturing complexity.
Solution Approach 2:
The invention replaces the mechanical coating process (requiring specialized coating equipment, solvent handling, and multiple steps) with a mechanical compression process (using standard tablet compression machinery). This substitution of the manufacturing mechanism simplifies the process while maintaining the pH-independent release特性.
4Duration of action of moving object
If sustained release formulation is designed for high solubility drugs, then therapeutic effect can be maintained, but initial burst release occurs due to pH-dependent mechanisms
Solution Approach 1:
The patent applies preliminary action by pre-organizing the drug within the polymer matrix during formulation preparation. The drug is thoroughly mixed and distributed within the Eudragit L100 and Kolidon SR matrix before compression, ensuring uniform dispersion and preventing surface accumulation that would cause burst release. This preliminary arrangement of drug-polymer distribution controls the release rate from the outset.
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 combination of pH-dependent and pH-independent release retardants in the dosage form achieves reproducible, pH-independent drug release with minimal initial burst release, reducing variability and manufacturing complexity, while maintaining the therapeutic effect over a longer period.
Implementation Method 1
at least one non-swelling pH dependent, release retardant
Implementation Method 2
at least one non-swelling pH independent, release-retardant
Implementation Method 3
minimizing swelling and variability in gastrointestinal transit profiles
Data Source
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AI summary
The novel sustained release dosage form comprising an active agent and a combination of a non-swelling pH dependent release retardant and a non swelling pH independent release retardant polymer which provides pH-independent drug release for a considerable period of time after administration.