Cryo-Milled PVA Powder for Continuous Melt Extrusion Dosing
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Solution Overview
Problem
The challenge in pharmaceutical formulations is the difficulty in uniformly dosing polyvinyl alcohol (PVA) with other ingredients into an extruder due to its chemical and physical properties, leading to material blockages and interruptions in the production process.
Innovation Solution
The development of a PVA grade, specifically PVA 4-88, which is cryo-milled to a particle size range of 45 to 1400 µm, preferably 50 to 300 µm, with a distribution of d10 = 20±10 µm, d20 = 30±10 µm, d50 = 70±10 µm, d90 = 200±30 µm, d99 = 300±30 µm, ensuring improved flowability and allowing continuous dosing without additives.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If polyvinyl alcohol is used as carrier material for extrusion, then the formulation can be produced by melt extrusion, but the material blocks the feeder and dosing is interrupted due to poor flowability
Solution Approach 1:
The patent changes the physical parameters of PVA by controlling particle size (45-1400 µm) and morphology through specific drying processes, transforming it from poor flowability to excellent flowability while maintaining melt extrusion capability
Solution Approach 2:
The patent utilizes phase transition during drying (spray drying, freeze drying, or spray freeze drying) to create particles with specific physical properties that enable both good flowability and melt extrusion, transitioning from liquid solution to solid particles with controlled morphology
2Ease of operation
If PVA particles are made smaller to improve flowability, then dosing becomes easier, but particle size distribution becomes harder to control
Solution Approach 1:
The patent defines specific particle size ranges (45-1400 µm) and distributions (d10, d20, d50, d90, d99 values) achieved through controlled drying parameters, balancing flowability with manufacturability
Solution Approach 2:
The patent creates particles with specific local properties through spray drying techniques, where the drying process creates a porous or hollow structure that improves flowability while maintaining controlled size distribution
3Ease of operation
If additives are added to improve PVA processing, then flowability improves, but the formulation becomes more complex
Solution Approach 1:
The patent makes PVA self-sufficient by creating particles with inherent flow-improving properties through drying process control, eliminating the need for external additives like glidants or flow agents
Solution Approach 2:
The patent uses phase transition during drying to create particles with porous or hollow structures that inherently improve flowability without requiring additional chemical additives
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 PVA grade enables uninterrupted feeding and dosing during processing, facilitating the formation of homogeneous mixtures with active ingredients, enhancing the extrusion process by ensuring uniformity and stability.
Implementation Method 1
which is cryo-milled and which has particle sizes in the range of 45 to 1400 µm
Data Source
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AI summary
The present invention relates to an improved powdered polyvinyl alcohol (PVA), which can be used for pharmaceutical products, and that due to its improved properties can be better dosed during formulation processes. Furthermore, this invention refers to pharmaceutical formulations comprising polyvinyl alcohol as carrier matrix and their use.