Stable Tetrahydrobiopterin Tablets via Polymorph B Crystallization
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Solution Overview
Problem
Tetrahydrobiopterin (BH4) is unstable and costly, leading to challenges in treatment due to rapid oxidation and short shelf-life, making existing formulations commercially undesirable and difficult to store, which affects the therapy of patients with phenylketonuria and other related disorders.
Innovation Solution
A stable solid formulation of tetrahydrobiopterin is developed using a dry tableting process with a crystalline form (polymorph B) that maintains stability at room temperature for extended periods, incorporating a pharmaceutically acceptable carrier and excipients without added water, and is packaged in humidity-controlled conditions to retain at least 95% of the active ingredient for several months.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If tetrahydrobiopterin is stored at room temperature, then ease of operation is improved, but stability deteriorates due to rapid oxidation and short shelf-life
Solution Approach 1:
The patent applies parameter changes by transitioning tetrahydrobiopterin from an unstable molecular state to a stable crystalline solid state through polymorphic form selection (polymorph B). This phase transition fundamentally alters the stability parameters, enabling room temperature storage without degradation while maintaining ease of operation.
Solution Approach 2:
The patent creates a composite formulation by combining tetrahydrobiopterin with specific excipients including anhydrous binders, acidic antioxidants, and lubricants. This composite material approach enhances stability through synergistic interactions among components, protecting the active ingredient from oxidation while maintaining manufacturability and storage convenience.
2Ease of manufacture
If conventional packaging is used for unstable BH4, then manufacturing cost is reduced, but reliability deteriorates due to degradation from improper storage
Solution Approach 1:
By changing the physical state and crystalline structure of BH4 to polymorph B, the patent eliminates the need for specialized cold chain packaging. Standard packaging suffices, reducing manufacturing costs while ensuring therapy reliability through inherent stability of the crystalline form at room temperature.
Solution Approach 2:
The patent replaces expensive, complex specialized packaging systems with simple, inexpensive standard packaging. The stability is achieved not through costly packaging barriers but through the intrinsic stability of the polymorphic form, allowing use of economical packaging materials.
3Ease of manufacture
If BH4 is formulated with water, then ease of manufacture is improved, but stability deteriorates due to enhanced oxidation and reduced shelf-life
Solution Approach 1:
The patent changes the moisture content parameter from hydrated to anhydrous state in the formulation. By eliminating water and selecting anhydrous excipients, the formulation achieves enhanced oxidation resistance while maintaining ease of manufacture through straightforward dry blending and compression processes.
Solution Approach 2:
The patent creates an inert, anhydrous environment within the tablet formulation by using water-free excipients and maintaining low moisture content. This inert environment protects BH4 from oxidation without complicating the manufacturing process, as the anhydrous state is inherently more stable and easier to handle.
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 stable tablets exhibit prolonged shelf-life, rapid disintegration, and improved handling properties, ensuring effective and stable delivery of BH4 for treating metabolic disorders like phenylketonuria and enhancing nitric oxide synthase activity without the need for expensive storage conditions.
Implementation Method 1
Drug substance polymorphic forms can exhibit different physical and mechanical properties... Polymorphic forms of the drug substance can undergo phase conversion when exposed to a range of manufacturing processes... The extent of conversion generally depends on the relative stability of the polymorphs
Implementation Method 2
Exemplary stable tablets of the invention have been prepared using a dry tableting process and have been shown to have a shelf-life of at least 6 to 9 months at room temperature
Implementation Method 3
Another significant problem with BH4 is that this compound is unstable and readily undergoes aerobic oxidation at room temperature... A stable solid formulation of tetrahydrobiopterin is developed using a dry tableting process... incorporating a pharmaceutically acceptable carrier and excipients without added water
Data Source
AI summary
The present invention is directed to a stable solid formulations of tetrahydrobiopterin, processes for producing them, and treatment methods using such formulations.