Sequential-Injection Syringe with Valve Stopper for Dead Volume Reduction
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Solution Overview
Problem
Existing drug delivery devices struggle with dead volume issues when increasing the concentration of active pharmaceutical ingredients, leading to inefficiencies in delivering the entire therapeutic composition to patients.
Innovation Solution
A sequential-injection syringe design that includes a barrel with a plunger rod and valve stoppers, allowing for the separation of the syringe interior into two chambers, one for a concentrated pharmaceutical composition and the other for a diluent, which are configured to minimize dead volume and ensure complete delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the concentration of the active pharmaceutical ingredient is increased to improve therapeutic stability, then the volume of therapeutic composition decreases, but dead volume within the container becomes a greater issue
Solution Approach 1:
The syringe interior is divided into two separate chambers (first chamber and second chamber) by a valve stopper. The first chamber contains diluent and the second chamber contains concentrated pharmaceutical composition. This segmentation allows the device to maintain high API concentration in the second chamber while providing a mechanism to deliver the entire dose including dead volume through sequential injection.
Solution Approach 2:
The syringe is pre-filled with both diluent in the first chamber and concentrated pharmaceutical composition in the second chamber before use. The valve stopper is pre-positioned to separate the chambers. During administration, the user first injects the concentrated composition, then activates the valve stopper to flush remaining composition from the second chamber into the first chamber for complete delivery.
2Loss of substance
If a valve stopper is introduced to separate chambers for sequential injection, then dead volume is effectively managed, but device complexity increases
Solution Approach 1:
The valve stopper serves multiple functions: it separates the two chambers to maintain concentration gradients, acts as a barrier to prevent mixing before intended, provides a mechanism for sequential injection, and enables complete delivery of the concentrated composition by being pushed into the distal end to flush remaining drug into the diluent chamber.
Solution Approach 2:
The valve stopper is nested within the syringe interior, movable along the plunger rod. The plunger rod passes through the valve stopper, allowing the valve stopper to be pushed distally by the plunger rod to activate the flushing function. This nested arrangement allows compact integration of the valve mechanism within the syringe barrel.
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 syringe effectively manages dead volume by using a valve stopper that maintains fluid isolation until a hydrostatic pressure disequilibrium causes the chambers to communicate, ensuring that the entire therapeutic composition is delivered to the patient.
Implementation Method 1
a hydrostatic pressure disequilibrium causes the second chamber to be in fluid communication with the first chamber
Data Source
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AI summary
Provided herein is a sequential-injection syringe having a barrel with a proximal end, a distal end having an opening, and a sidewall therebetween defining a syringe interior, a plunger rod at least partially received within the syringe interior and slidable relative to the barrel, the plunger rod having a proximal end and a distal end, a plunger stopper arranged at the distal end of the plunger rod, a valve stopper arranged in the syringe interior and configured to separate the syringe interior into a first chamber and a second chamber, a concentrated pharmaceutical composition received within the second chamber, and a diluent received within the first chamber.