Epoprostenol Sodium Stability via Alkaline pH Control
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Solution Overview
Problem
Epoprostenol sodium, a key drug for treating pulmonary hypertension, is chemically unstable and degrades rapidly in aqueous solutions, making it challenging to store and maintain stability for extended periods.
Innovation Solution
The method involves preparing epoprostenol sodium in the presence of an inorganic base or basic-hydrolyzing inorganic salt to create a high pH environment (pH > 11), which significantly enhances stability, allowing the drug to be stored in a deep freezer at -20±5° C. for at least 3 years without significant decomposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If epoprostenol sodium is stored in aqueous solution at room temperature, then it is readily available for use, but it degrades rapidly with a half-life of only 3-4 minutes
Solution Approach 1:
The patent applies parameter changes by adjusting the pH of the aqueous solution to a highly alkaline range (pH 12-14) using inorganic bases such as sodium hydroxide, potassium hydroxide, or ammonium hydroxide. This drastic pH change transforms the degradation pathway and dramatically extends the half-life of epoprostenol sodium from minutes to hours at room temperature, resolving the contradiction between availability and stability.
Solution Approach 2:
The patent employs preliminary action by pre-adjusting the pH of the solution to highly alkaline conditions before storage. This preliminary pH adjustment creates a stable environment that prevents degradation during storage and transport, ensuring the drug remains stable and effective until administration. The alkaline environment is established in advance to counteract the rapid degradation that would otherwise occur.
2Duration of action of stationary object
If epoprostenol sodium is stored in deep freezer, then long-term stability is achieved, but it requires cold chain storage and cannot be stored at room temperature
Solution Approach 1:
The patent applies parameter changes by modifying the pH parameter to highly alkaline conditions (pH 12-14), which fundamentally alters the storage requirements. This parameter change enables the drug to maintain stability at room temperature for extended periods (days to weeks) without freezing, eliminating the need for cold chain storage and significantly improving storage convenience while maintaining long-term stability.
Solution Approach 2:
The patent employs preliminary action by pre-adjusting the pH to highly alkaline conditions and optionally adding stabilizing excipients before storage. This preliminary preparation creates a stable formulation that can be stored at room temperature for extended periods, eliminating the need for subsequent freezing and simplifying the storage process while achieving long-term stability.
3Ease of manufacture
If conventional synthesis methods are used, then epoprostenol sodium can be produced, but the product degrades quickly and requires immediate use or freezing
Solution Approach 1:
The patent applies parameter changes by adjusting the pH of the final product formulation to highly alkaline conditions (pH 12-14) using inorganic bases. This parameter change in the formulation process transforms the stability characteristics of the synthesized product, enabling it to maintain its composition for extended periods at room temperature without requiring immediate use or freezing, thus resolving the contradiction between ease of manufacture and product stability.
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 ensures that epoprostenol sodium remains stable for an extended period, with minimal decomposition of the 6-oxo-PGF1alpha impurity, maintaining 90% of its active content for 14-48 hours at room temperature and up to 6 months in a refrigerator, and can be stored for at least 3 years in a deep freezer.
Implementation Method 1
preparing epoprostenol sodium in the presence of an inorganic base or basic-hydrolyzing inorganic salt to create a high pH environment (pH > 11), which significantly enhances stability
Implementation Method 2
The aqueous solution of the epoprostenol sodium salt is lyophilized in the presence of an inorganic base or a basic-hydrolyzing inorganic salt ensuring the pH>11 medium
Data Source
AI summary
The invention provides a stable epoprostenol sodium and a process for the preparation this pharmaceutically active ingredient.