Multilayer Pellet Formulation for Colon-Targeted Budesonide Release
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Solution Overview
Problem
Conventional pharmaceutical formulations fail to deliver budesonide effectively to the distal colon for treating inflammatory processes, such as ulcerative colitis, as they do not ensure a high concentration of the active ingredient at the site of inflammation, leading to inadequate release in the colon.
Innovation Solution
A multilayer pellet dosage form with a specific structure and composition, including a starter pellet, active ingredient layer, swelling layer, sustained-release layer, and enteric-coated outer layer, designed to resist gastric juice and release budesonide only in the intestinal environment, ensuring delayed and continuous release in the colon.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional pharmaceutical formulations are used for oral administration, then the formulation is easy to administer, but the active ingredient cannot be made available in effective concentrations at the site of action in the colon
Solution Approach 1:
The pellet is divided into multiple functional layers: a core layer containing the active ingredient, an intermediate layer with pH-sensitive polymers, and an outer layer with additional protective and release-controlling materials. This segmentation allows each layer to perform its specific function in the gastrointestinal tract, ensuring reliable colon delivery while maintaining oral administration simplicity.
Solution Approach 2:
The formulation utilizes pH-dependent solubility changes of the polymer layers to control drug release. The intermediate layer contains polymers that remain intact in the acidic stomach environment (pH 1-3) but dissolve at the higher pH of the colon (pH 6.8-7.4), thereby changing the release parameter based on the gastrointestinal environment.
2Productivity
If the active ingredient is released immediately after stomach passage, then the release is rapid and complete, but only a small amount of active ingredient reaches the colon
Solution Approach 1:
The intermediate layer is designed to resist dissolution in the acidic stomach environment preliminarily, preventing premature release of the active ingredient. This protective barrier remains intact during gastric passage and only dissolves when it encounters the higher pH environment of the colon, ensuring the active ingredient reaches the target site before release.
Solution Approach 2:
The formulation exploits the pH parameter change between the stomach (acidic) and colon (alkaline) environments to control release timing. The polymer layer's solubility changes with pH, maintaining stability in the stomach and dissolving in the colon, thereby achieving rapid release only at the desired location.
3Ease of manufacture
If a single-layer coating is used on the pellets, then the manufacturing is simpler, but the desired delayed and continuous release in the colon is not achieved
Solution Approach 1:
The coating is segmented into distinct functional layers: an intermediate layer with pH-sensitive polymers for delayed release initiation, and an outer layer with additional polymers for sustained release control. This multi-layer structure, while more complex than a single layer, provides the necessary temporal control for delayed and continuous release over 8-10 hours in the colon.
Solution Approach 2:
The coating utilizes composite materials comprising different polymer types with complementary properties: enteric-coated polymers for pH-dependent dissolution and sustained-release polymers for extended release duration. This composite approach achieves the desired release profile that neither material could provide alone.
4Productivity
If the active ingredient is released in the small intestine, then the release occurs early, but the concentration at the distal colon site is insufficient for treating inflammatory processes
Solution Approach 1:
The formulation is designed to respond to the pH parameter change that occurs along the gastrointestinal tract. The polymer layer remains stable in the acidic small intestine environment (pH 2-3) and only dissolves when encountering the higher pH of the colon (pH 6.8-7.4), thereby achieving precise location accuracy for distal colon delivery.
Solution Approach 2:
The pH-sensitive polymer layer acts as an intermediary barrier between the active ingredient and the gastrointestinal environment. This intermediary remains intact in the small intestine, preventing premature release, and only dissolves in the colon where it mediates the release of the active ingredient at the precise target location.
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 multilayer pellet formulation achieves a prolonged and controlled release of budesonide in the colon, with over 85% of the active ingredient being released uniformly over 8-10 hours, effectively targeting the inflamed areas and reducing systemic absorption.
Implementation Method 1
a swelling layer that is applied directly to the active ingredient layer and contains swelling materials that swell upon contact with intestinal fluid
Implementation Method 2
an enteric-coated outer layer that does not dissolve at a pH value of less than 6.5 but dissolves in intestinal fluid at a pH value of more than 6.5
Implementation Method 3
a sustained-release layer that does not dissolve even in intestinal fluid at a pH > 6.5, but for liquids is permeable
Data Source
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AI summary
An optimized pharmaceutical formulation for the treatment of inflammatory diseases of the colon is disclosed, wherein the pharmaceutical formulation is a capsule containing pellets, which capsule is suitable for oral administration and delivers the active substance in a targeted manner to the site of action, namely the colon. This is achieved by a complex and multiple coating of pellets, which permit a modified release of active substance. The release of the active substance is at its maximum only in the colon, with at the same time low blood plasma levels. The results of the pharmaceutical tests concerning in vitro release are corroborated by the results in pharmacokinetic and clinical studies and the clinical efficacy demonstrated by these. The formulation according to the invention has very good medicinal safety.