Dry-Powder Inhaler Blister Isolation and Contamination Control
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Solution Overview
Problem
Existing dry-powder inhalers face challenges in maintaining dosing consistency and minimizing the risk of over-dosing due to residual medicament contamination from used portions of the blister pack.
Innovation Solution
The inhaler design incorporates internal transverse walls to isolate used and unused portions of the blister pack, along with driven winding wheels for the cover and base sheets, and a unitary manifold component to minimize contamination and ensure precise dosing, featuring a medicament dispensing mechanism that peels the cover sheet away from the base sheet to open blister pockets for aerosolization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the used portion of the blister pack is stored in the same space as the unused portion, then the device complexity is reduced, but the risk of medicament contamination increases
Solution Approach 1:
The housing is divided into separate compartments: a first compartment for storing the used portion of the blister pack and a second compartment for storing the unused portion. This segmentation physically isolates the used portion from the unused portion, preventing residual medicament on the used portion from contaminating the unused medicament doses while maintaining organized storage within the device.
2Ease of operation
If the cover sheet is peeled away completely, then the medicament dispensing mechanism operates smoothly, but residual medicament on the cover sheet can contaminate unused portions
Solution Approach 1:
The cover sheet is completely separated from the base sheet after the blister pocket is opened, and the used portion of the cover sheet is extracted and stored in the first compartment of the housing. This extraction removes the potential contamination source (residual medicament on the peeled cover sheet) from proximity to the unused medicament portions, preventing cross-contamination while maintaining smooth operation of the dispensing mechanism.
3Volume of stationary object
If a single compartment stores both used and unused blister portions, then the device size is minimized, but dosing consistency deteriorates due to contamination risk
Solution Approach 1:
The housing is segmented into distinct compartments for used and unused blister portions, creating physical barriers that prevent contamination. This segmentation ensures dosing consistency by protecting unused medicament from exposure to residual medicament on used portions, while the overall housing design maintains compact dimensions suitable for portable use.
Solution Approach 2:
Different regions of the housing are assigned different functions with appropriate environmental characteristics: the first compartment stores used portions isolated from contamination, while the second compartment stores unused portions in a protected environment. This local differentiation of storage conditions maintains dosing consistency throughout the product lifecycle.
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 design enhances dosing consistency, reduces the risk of over-dosing by preventing residual medicament contamination, and minimizes medicament loss during use, while allowing for easy accommodation of different formulation characteristics.
Implementation Method 1
a driven cover sheet winding wheel for winding up the used portion of the cover sheet
Implementation Method 2
The airflow passing through the mouthpiece and the manifold entrains the dry-powder medicament contained within the opened blister pocket, which medicament is delivered to the patient in aerosolised form
Implementation Method 3
The airflow passing through the mouthpiece and the manifold entrains the dry-powder medicament contained within the opened blister pocket
Data Source
AI summary
An inhaler for delivering dry-powder medicament to a patient from an open blister pocket of a blister pack. The blister pack is in the form of a flexible elongate strip including a base sheet having a plurality of recesses spaced along its length and a cover sheet peelably sealed to the base sheet to define a plurality of blister pockets each containing a measured dose of the medicament. The inhaler also includes a housing for enclosing used and unused portions of the blister pack together with the medicament dispensing mechanism. The housing defines internal transverse walls extending in the width direction of the blister pack for isolating the used portion of the cover sheet from the unused portion of the blister pack.