Contact Lens Holder for In Vitro Testing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional in vitro testing methods lack effective apparatus for holding contact lenses, leading to deformation during testing, which compromises the accuracy of release rate data due to inadequate contact with the dissolution medium.
Innovation Solution
A contact lens holding apparatus comprising a first support member, a second support member, an alignment rod, and a cage member, which cooperatively define an annular space for receiving the contact lens, allowing for fluid flow paths and maintaining the lens's shape, with a locking mechanism for adjustable positioning and a drivable component for movement during testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional sample holders are used for contact lens testing, then the testing can be performed with standard apparatus, but the contact lens becomes deformed during testing
Solution Approach 1:
The holder is divided into multiple components: a first support member with a body portion and first end cap, a second support member with second end cap, and a cage member with multiple openings. This segmented structure allows the contact lens to be held without deformation while enabling fluid flow through the openings for proper dissolution testing.
Solution Approach 2:
The cage member is positioned coaxially about the body portion of the first support member, with the contact lens positioned within the annular space defined by the cage member and body portion. This nested arrangement maintains the contact lens shape while allowing dissolution medium to flow through the cage member openings.
2Shape
If the contact lens is held rigidly to maintain shape, then the lens shape is preserved, but the dissolution medium cannot freely contact the lens surfaces
Solution Approach 1:
The cage member is designed with a plurality of openings between its inner and outer surfaces, creating a porous-like structure that allows dissolution medium to flow through while the cage member itself maintains the contact lens shape. This enables both shape preservation and adequate medium contact.
Solution Approach 2:
The design transitions from a solid continuous structure to one with multiple openings, adding dimensional complexity to enable fluid flow paths while maintaining the overall shape-maintaining function of the holder.
3Ease of manufacture
If the holder structure is simplified for ease of manufacture, then manufacturing is easier, but the holder cannot maintain contact lens shape and enable proper fluid flow
Solution Approach 1:
By dividing the holder into separate components (first support member, second support member, cage member), each component can be manufactured independently using standard techniques, then assembled together to achieve the complex function of shape maintenance and fluid flow.
Solution Approach 2:
The cage member serves multiple functions: it maintains the contact lens shape, allows dissolution medium flow through its openings, and can be positioned coaxially about the body portion. This multi-functionality is achieved through a single component design that can be manufactured using conventional methods.
Data Source
AI summary
An apparatus for holding a contact lens during in vitro testing includes a first support member, a second support member, an alignment rod, and a cage member. The first support member includes a first end cap and a body portion. The body portion includes grooves formed in a lateral surface extending from the first end cap. The alignment rod is configured for interconnecting the body portion and a second end cap of the second support member. The cage member is positionable about the body portion between the first and second end caps, and includes an inner surface, an outer surface, and a plurality of openings between the inner surface and the outer surface. The inner surface and the lateral surface cooperatively define an annular space therebetween and a plurality of fluid flow paths between the inner space and the openings. The annular space is configured for receiving the contact lens.