Process for removing components from solutions

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BACKGROUND OF THE INVENTION

The present invention relates to a solution dispenser, and more particularly to a dispenser in which preservatives and other components may be removed from the solution as a solution is dispensed.

Many solutions are available for making contact lenses more comfortable, safer, and easier to wear. For example, wetting solutions facilitate the wetting of a lens, soaking solutions serve as anti-microbial storage medium and prevent dehydration and distortion of the lens, and cleaning solutions remove accumulated eye secretions and other contaminants from lenses. A large number of other solutions are also used by contact lens patients. These ophthalmic solutions are typically marketed in squeezable plastic containers or aerosol cans having a nozzle through which the solution is dispensed.

Because these solutions come in contact either directly or indirectly with the eye, it is very important that they be free of microbial growth. To this end, it is common practice for preservatives to be provided in these solutions. Among the preservatives used in ophthalmic solutions are polymoxin B sulfate, quaternary ammonium compounds, chlorobutanol, organic mercurials, p-hydroxybenzoic acid esters, and certain phenyls and substituted alcohols.

A problem exists, however, in that the preservatives used in the ophthalmic solutions can cause eye irritation if used in high concentrations. For example, benzalkonium chloride (BAK) is used as a preservative in ophthalmic solutions and has broad anti-bacterial and anti-fungal activity when used with other components, such as disodium ethylene diaminetetraacetic acid (EDTA). However, it has been reported that repeated use of BAK can denature the corneal protein and cause irreversible eye damage. Also, in addition to chemical sensitivity, a number of contact lens wearers have allergic reactions to the preservatives used in ophthalmic solutions, even at relatively low concentrations.

The typical remedy for overcoming chemical sensitivity and allergic reactions to preservatives in ophthalmic solutions entails switching the patients to an unpreserved solution. However, unpreserved solutions present problems in marketing, as well as in home storage, in that once the container housing the solution is opened, the solution quickly becomes contaminated and unsuitable for further use. They also tend to be very expensive to produce.

Therefore, there exists a need for an apparatus which removes preservatives, as well as other components, from a solution as the solution is dispensed to a patient.

There exists a further need for such an apparatus which is easily manufactured and economical to use.

There exists a further need for an apparatus which may be attached to a standard solution container.

SUMMARY OF THE INVENTION

The present invention relates to a device for removing a component, including but not limited to preservatives, from ophthalmic and other solutions as the solution is dispensed from a container. The device preferably comprises a container having squeezable sidewalls defining a solution retaining chamber, but may also be an aerosol can or other container. The container also preferably includes a neck portion and a dispensing head having a container outlet on its end through which the solution is dispensed. Means for removing the component from the solution as the solution is dispensed from the chamber through the container outlet are also provided.

In a first embodiment, the means for removing a component from the solution comprise a scavenging material provided within the path of the solution as the solution is dispensed. In this embodiment, the device is a standard solution container housing a solution having the component to be removed, and the scavenging material is held within the dispensing head. The scavenging material may have a positive charge for scavenging negatively charged components or it may have a negative charge for scavenging positively charged components or it may be a material which selectively scavenges components by a size exclusion mechanism or it or may comprise any other means for removing a component from solution.

In an alternative embodiment, a fitment may be utilized having a fitment body which is releasably engagable with a standard solution container. The fitment includes passage means within its body for allowing passing of the solution from the container to a fitment outlet. In this embodiment, the means for removing a component may comprise a scavenging material provided within the fitment so as to be within the path of the solution as the solution is dispensed from the container outlet to the fitment outlet. The fitment has the advantage of being able to be adapted to standard solution containers.

Also, means for providing a control of the flow of solution out of the container may be provided. For example, a check valve may be provided within the final dispensing outlet to prevent backflow of solution into the container following use. Additionally, means for regulating the flow of air into the container, namely, a second check valve, may be placed within the neck portion of a squeezable container for allowing air to flow into a depressed container, thereby restoring the container to its original shape. This embodiment will minimize the incidence of microbial growth in the area of the dispensing head proximate the final dispensing outlet.

Therefore, it is an object of the present invention to provide an apparatus which removes preservatives, as well as other components, from a solution as the solution is dispensed to a patient.

It is also an object of the present invention to provide such an apparatus which is easily manufactured and economical to use.

It is also an object of the present invention to provide such an apparatus which may be adapted to a standard solution container. These and other objects and advantages will be more apparent from the following detailed description of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of a first embodiment of the present invention in which scavenging material is provided within a container;

FIG. 2 is a partial cross-sectional view of a first embodiment of the present invention in which scavenging material is provided within a container;

FIG. 3 is an exploded view of a second embodiment of the present invention in which scavenging material is provided within a fitment;

FIG. 4 is a partial cross-sectional view of a second embodiment of the present invention in which scavenging material is provided within a fitment;

FIG. 5 is a partial cross-sectional view of an embodiment of the present invention in which the dispensing head is snap-fitted onto a container; and

FIG. 6 is a partial cross-sectional view of an embodiment of the present invention having means for providing one-directional flow of solution out of a container.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the figures, a device 10 for removing components, such as preservatives, from solutions, such as an ophthalmic solution, is shown. The device 10 includes a container 12, preferably constructed of molded plastic, having resilient sidewalls 14 which define a solution retaining chamber and which preferably may be deformed by inward pressure to produce a pressure within the container 12 for using and dispensing its contents. The container 12 is provided with an upstanding neck portion 16 having external threads 18 thereabout. A dispensing head 20 is provided atop the neck portion 16, either integrally, as shown in FIGS. 1-4, by threading engagement, or by snap-fitting engagement as shown in FIGS. 5 and 6. A flange portion 22 is provided between the dispensing head 20 and the container neck 16. The dispensing head 20 has passage means, such as a duct or other passageway, through its length which in turn has a first end in communication with the chamber and a container outlet 24 at the other end.

In a first embodiment of the present invention, shown in FIGS. 1 and 2, means for removing preservatives or other components are placed directly within the dispenser head 20. In its preferred form, the preservative removing means comprise scavenging material 26 provided intermediate the chamber and the container outlet 24, so as to be within the path of the solution as the solution is dispensed from the container 12. The material 26 should be positioned as close as possible to the outlet 24 to minimize empty space in the upper portion of the dispensing head 20. The material 26 may be compressed into a porous mass which is preferably insert molded into the dispensing head 20. However, any other means of maintaining the material in the path of the solution may also be used. Alternatively, as shown in FIG. 2, the material 26 may be in the