Two-Stage Intravitreal Auto-Injector for Viscous Drug Dosing
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Solution Overview
Problem
The viscosity of gel-based or semi-solid drug formulations for ophthalmological use poses challenges in accurate injection, particularly for intravitreal delivery, leading to difficult procedures and potential complications, and conventional devices often require surgical intervention.
Innovation Solution
An auto-injector device with a two-stage mechanism, comprising an injector body, syringe plunger, compression spring, preparatory pin, and injection pin, designed to safely administer viscous formulations by releasing lubricious material and drug composition in stages, preventing air trapping and ensuring accurate dosing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If gel-based or semi-solid drug formulations are used for extended release, then therapeutic agents can be released over weeks or months, but the viscosity makes injection force much higher and accurate volume measurement extremely difficult
Solution Approach 1:
The injection process is divided into two distinct stages: a preparatory stage where lubricious material is injected first to coat the needle and create a lubricating layer, followed by a second stage where the viscous drug formulation is injected. This segmentation reduces the overall injection force required by eliminating direct friction between the viscous formulation and needle walls.
Solution Approach 2:
A lubricious material is introduced as an intermediary substance between the injection needle and the viscous drug formulation. This intermediate layer reduces friction and allows the highly viscous gel-based formulation to be injected with significantly lower force than would be required without the lubricating layer.
2Duration of action of moving object
If gel-based or semi-solid drug formulations are used, then extended release is achieved, but air can get trapped in the syringe and accurate volume measurement becomes extremely difficult
Solution Approach 1:
The lubricious material is injected in advance before the drug formulation, performing a preliminary action of coating the needle interior surfaces. This preliminary lubrication prevents air entrapment and allows for smoother, more controlled injection of the viscous formulation, improving volume accuracy.
Solution Approach 2:
The lubricious material serves as an intermediary that eliminates air pockets and creates a smooth flow path for the viscous drug formulation. This intermediate layer ensures complete displacement of air and enables precise control of the injected volume.
3Ease of operation
If conventional devices are used for intravitreal injection of viscous formulations, then injection can be performed, but the procedure becomes very difficult and may require surgical intervention
Solution Approach 1:
The injection device and procedure are segmented into two stages: preparatory injection of lubricious material and subsequent injection of drug formulation. This segmentation simplifies the overall procedure by breaking down the difficult task of injecting viscous material into manageable steps that can be performed with a conventional syringe and needle.
Solution Approach 2:
The lubricious material acts as an intermediary that facilitates the injection process. By introducing this intermediate substance first, the procedure becomes significantly easier to perform with conventional devices, eliminating the need for specialized equipment or surgical intervention.
4Measurement precision
If two-stage injection mechanism is implemented, then accurate dosing and prevention of air trapping are achieved, but device complexity increases
Solution Approach 1:
The syringe is divided into two separate compartments: a first compartment for lubricious material and a second compartment for drug formulation. This physical segmentation enables the two-stage injection process, ensuring accurate dosing by preventing mixing of materials and eliminating air entrapment through the sequential injection mechanism.
Solution Approach 2:
The two-stage injection system can be implemented by nesting the first compartment within or alongside the second compartment in the syringe assembly. This nested arrangement allows both materials to be contained in a single injection device while maintaining the ability to inject them sequentially, achieving accurate dosing without requiring multiple separate devices.
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 auto-injector device facilitates safe and accurate administration of viscous drug formulations in an outpatient setting, reducing the risk of complications and eliminating the need for surgery.
Implementation Method 1
an auto-injector spring
Implementation Method 2
releasing lubricious material
Data Source
AI summary
In accordance with the purpose(s) of the present disclosure, as embodied and broadly described herein, the disclosure relates to an auto-injector device that can be used for injection of ophthalmological formulations. The auto-injector device can function in two stages, where a lubricious material is released in a first stage and a drug delivery composition is released in a second stage. The present disclosure provides for method of using these injector devices.