Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Tablets – lozenges – or pills
Reexamination Certificate
2001-07-27
2003-02-04
Dees, Jose′ G. (Department: 1616)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Tablets, lozenges, or pills
C424S078040
Reexamination Certificate
active
06514528
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to a composition and method for storing, preserving and dispensing solutions for cleaning and disinfecting contact lenses.
BACKGROUND
Biguanide disinfectants such as alexidine and PHMB are widely used as antimicrobials in ophthalmic solutions, for example, contact lens cleaning, disinfecting and have been commercialized in various products, typically at levels of about 1 ppm or less for use with soft contact lenses. It is generally desirable to provide the lowest possible level of antimicrobial that is consistent with reliable disinfection in order to provide a generous margin for safety and comfort.
U.S. Pat. No. 4,758,595 to Ogunbiyi et al. discloses a contact-lens solution containing a polyaminopropyl biguanide (PAPB), also known as polyhexamethylene biguanide (PHMB) in combination with a borate buffer. These disinfecting and preservative solutions are especially noteworthy for their broad spectrum of bactericidal and fungicidal activity at low concentrations coupled with very low toxicity when used with soft-type contact lenses.
Some of the most popular products for disinfecting lenses are multipurpose solutions that can be used to clean, disinfect and wet contact lenses, followed by direct insertion (placement on the eye) without rinsing. Obviously, the ability to use a single solution for contact-lens care is an advantage. Such a solution, however, must be particularly gentle to the eye, since, as indicated above, some of the solution will be on the lens when inserted and will come into contact with the eye.
With conventional contact-lens cleaners or disinfectants, including multi-purpose solutions, lens wearers typically need to digitally or manually rub the contact lenses (typically between a finger and palm or between fingers) during treatment of the contact lenses. The necessity for the daily “rubbing” of contact lenses adds to the time and effort involved in the daily care of contact lenses. Many contact-lens wearers dislike having to perform such a regimen or consider it to be an inconvenience. Some wearers may be negligent in the proper “rubbing” regimen, which may result in contact-lens discomfort and other problems. Sometimes rubbing, if performed too rigorously, which is particularly apt to occur with beginning lens wearers, may damage the lenses. This can be problematic when a replacement lens is not immediately available.
Contact lens solutions that qualify as a “Chemical Disinfecting Solution” do not require rubbing to meet biocidal performance criteria (for destroying representative bacteria and fungi) set by the US Food and Drug Administration (FDA) under the Premarket Notification (510k) Guidance Document For Contact Lens Care Products, May 1, 1997. In contrast, a contact-lens solution, referred to as a “Chemical Disinfecting System,” that does not qualify as a Chemical Disinfecting Solution, requires a rubbing regimen to pass biocidal performance criteria. Traditionally, multi-purpose solutions (used for disinfecting and wetting or for disinfecting, cleaning, and wetting) have qualified as a Chemical Disinfecting System, but not as a Chemical Disinfecting Solution.
A Chemical Disinfecting Solution would generally require a more efficacious or stronger disinfectant than a Chemical Disinfecting System. The stronger the biocidal effect of a solution, however, the more likely that it may exhibit toxic effects or adversely effect lens-wearer comfort. For example, many very efficacious bactericides used in other contexts, such as mouthwashes, cosmetics, or shampoos, while being sufficiently safe for use in such products, would be too toxic for ophthalmic use, especially for use with soft lenses because of the above-mentioned tendency of soft lenses to bind chemicals and the sensitivity of eye tissues. Similarly, the concentrations of certain bactericides may need to be within lower limits in solutions for use with soft contact lenses than in other products or in solutions for other types of lenses, especially when such solutions are not rinsed from the contact lens before placing the lens in the eye.
The solution further needs to be stable over the shelf life of the product. U.S. Pat. No. 6,180,093 to De et al. notes that interaction between small low-density poly(ethylene) (LDPE) containers and certain antimicrobials may reduce the efficacy of the antimicrobials.
It would be desirable to obtain a contact-lens solution that would simultaneously provide both (1) an increased level and/or broader spectrum of biocidal activity, and (2) a low order of toxicity to eye tissue, such that the solution can be used to treat a contact lens such that the lens can subsequently be placed on the eye without rinsing the solution from the lens. While challenging to develop, it would be especially desirable to obtain a Chemical Disinfecting Solution that could be used for soft contact lenses and that would allow direct placement of a contact lens on an eye following soaking in the solution and/or rinsing and rewetting with the solution. Such a product may provide increased efficacy, resulting in greater protection to the lens wearer against infection caused by microorganisms, while providing maximum convenience. Finally, it would be desirable for the biocidal efficacy of the disinfecting solution to be sufficiently high to achieve the efficacious disinfection, or at least not inherently inefficacious disinfection, of a contact lens with respect to bacteria and fungi in the event, for whatever reason, that the contact lens wearer does not carry out a regimen involving mechanical rubbing or the like using the contact-lens solution.
SUMMARY OF THE INVENTION
The invention provides, in a first aspect, a method and composition for inhibiting the binding of a biguanide disinfectant in aqueous solution to a poly(ethylene) solid in contact with said solution comprising providing in said solution an amount of cyclodextrin sufficient to inhibit binding of the biguanide disinfectant to the poly(ethylene) solid. The composition of the invention may comprise additional components, for example, at least one selected from the group consisting of buffers, sequestering and/or chelating agents, tonicity adjusting agents, surfactants, pH adjusting agents and viscosity builders.
The invention also provides a method and composition for cleaning contact lenses is provided comprising contacting the lenses with a composition containing an effective amount of one or more biguanide disinfectants and from 0.0001% to about 10% by weight of one or more cyclodextrins for a time sufficient to clean the lenses. In a preferred embodiment, the composition is a multipurpose contact lens solution for cleaning and disinfecting contact lenses, and contains other components such as including buffers, chelating and/or sequestering agents, tonicity adjusting agents, surfactants, pH adjusting agents and viscosity builders.
The invention still further provides a composition for rewetting, disinfecting and/or cleaning contact lenses comprising at least one biguanide antimicrobial and an amount of cyclodextrin that is insufficient of itself to effectively clean contact lenses if that amount of cyclodextrin were present in the solution in the absence of at least one other cleaning agent. In a preferred embodiment, the composition comprises a biguanide disinfectant selected from the group consisting of poly(hexamethylene) biguanide and alexidine. The composition preferably comprises at least one buffer at least one chelating agent or sequestering agent. The composition may suitably comprise at least one tonicity-adjusting agent, as well as surfactants, pH adjusting agents and viscosity builders.
DESCRIPTION OF THE INVENTION
The composition of the present invention is, in one embodiment, an aqueous biguanide-containing solution disinfecting solution, for example, a multipurpose contact lens solution. The composition of the invention contains one or more cyclodextrins together with one or more biguanide disinfectants in a suitable carrier. Other active or inactive compon
Denick, Jr. John
Smerbeck Richard V.
Xia Erning
Bausch & Lomb Incorporated
Dees Jose′ G.
DeWitty Robert M
Furr, Jr. Robert B.
Vacca Rita D.
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