Dry Powder Inhaler Blister Cyclone for API-Carrier Separation
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Solution Overview
Problem
Conventional inhalers fail to effectively deagglomerate active pharmaceutical ingredients (API) from carrier particles in dry powdered medicaments, leading to API deposition in the throat instead of the lungs, especially for larger dose sizes, and carrier particles adhere to inhaler surfaces, causing operational issues and safety concerns.
Innovation Solution
A drug-delivery device with an inhaler apparatus and blister design that creates a cyclonic airflow within the blister to separate API from carrier particles by positioning air inlets tangentially, ensuring API particles are preferentially drawn through the outlet while carrier particles remain in the blister.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If API particles are blended with carrier particles for ease of handling, then handling during manufacturing and packaging is improved, but API particles remain adhered to carrier particles and cannot be effectively delivered to lungs
Solution Approach 1:
The device separates the API and carrier particles through a classification mechanism with multiple outlets. Smaller API particles exit through a first outlet while larger carrier particles exit through a second outlet, achieving deagglomeration and effective separation that enables reliable API delivery to lungs while maintaining the blending benefits for handling.
Solution Approach 2:
Different regions of the device provide different functions: the blending region facilitates handling during manufacturing, while the classification region with differentiated outlets enables separation for effective lung delivery. This local differentiation of function resolves the contradiction between handling ease and delivery reliability.
2Device complexity
If passive inhalation is used to deagglomerate medicament, then device complexity is reduced, but deagglomeration efficiency is insufficient especially for larger dose sizes
Solution Approach 1:
The device utilizes the dynamic characteristics of user inhalation flow to create different flow regimes. By designing the classification chamber geometry and outlet configurations, the system transforms the user's inhalation into dynamic flow patterns that enable effective deagglomeration and classification without requiring additional active components, thus maintaining simplicity while improving efficiency.
Solution Approach 2:
The device changes the flow parameters (velocity, pressure, turbulence) through its geometric design to enhance deagglomeration efficiency. The classification chamber and outlet configurations create optimal flow conditions that separate particles by size effectively, allowing passive inhalation to achieve sufficient deagglomeration even for larger dose sizes without increasing device complexity.
3Ease of operation
If carrier particles are used to enhance handling, then ease of handling is improved, but carrier particles deposit in throat and mouth instead of reaching lungs
Solution Approach 1:
The device extracts and removes the harmful component (carrier particles with adhered API) from the inhalable fraction through classification. By separating particles based on size at the outlet stage, the system ensures that only smaller API particles are delivered to the lungs while larger carrier particles are excluded, preventing throat deposition and maximizing API delivery efficiency.
Solution Approach 2:
The device converts the potential harm of carrier particle inhalation into a benefit by using the size difference between API and carrier particles as the basis for classification. The carrier particles, which would otherwise cause throat deposition, are now used as a means to enable effective separation and ensure only respirable API particles are inhaled.
4Quantity of substance
If larger dose sizes are used to increase therapeutic effect, then therapeutic efficacy is improved, but deagglomeration becomes more difficult with limited inhalation energy
Solution Approach 1:
The device addresses the deagglomeration challenge by adding a spatial classification dimension. Instead of relying solely on inhalation energy to break up agglomerates, the system uses a classification chamber with differentiated outlets that separate particles by size. This dimensional approach allows larger dose sizes to be effectively deagglomerated and classified without requiring proportionally higher inhalation energy.
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 device achieves high deagglomeration and classification efficiency, with over 70-94% of API particles being inhaled and carrier particles retained in the blister, enhancing therapeutic delivery and safety by minimizing residual medicament in the inhaler.
Implementation Method 1
The inlets are positioned and configured to direct a flow of air into the blister in a tangential direction, so that a cyclonic airflow is created within the blister
Implementation Method 2
the inlets are positioned and configured to direct a flow of air into the blister in a tangential direction, so that a circulating airflow is created within the blister
Data Source
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Figure 3
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AI summary
A powdered medicament comprising an active pharmaceutical ingredient (API) and a carrier powder is provided in a circular blister. In a drug delivery device, an inhaler apparatus has an air outlet piercer for axially piercing the blister, and three, four or five air-inlet piercers, each for piercing an inlet opening into the blister, for directing air into the blister when air is drawn through the outlet by a user inhaling through the inhaler apparatus. The inlets direct a tangential airflow into the blister to set up a cyclonic airflow which deagglomerates the powdered medicament so that the API is separated from the carrier particles and is carried, in the airflow, through the outlet piercer for inhalation. In use, an upstream end of each air inlet presents a streamlined profile to the cyclonic airflow within the blister, one or more of the air-inlet piercers extend(s) into the blister by less than the distance which the air-outlet piercer extends into the blister, and one or more of the inlets is/are spaced from an outer edge of the blister by more than 10% of the diameter of the blister, and from a central axis of the blister by more than 10% of the diameter of the blister. In use, the cyclonic airflow within the blister creates a low pressure core in the region of the air outlet piercer. The circulating cyclonic airflow thus carries the powdered medicament and accelerates it radially outwards within the blister, such that flow of the API towards the low pressure core and through the air outlet is favoured relative to flow of the carrier powder through the outlet.