Packaging solutions

This application claims benefit of Provisional Patent Application No. 60/989,485 filed Nov. 21, 2007 which is incorporated by reference herein.

1. Technical Field

The present invention generally relates to packaging solutions for contact lenses.

2. Description of Related Art

Blister-packs and glass vials are typically used to individually package each soft contact lens for sale to a customer. Saline or deionized water is commonly used to store the lens in the blister-packs, as mentioned in various patents related to the packaging or manufacturing of contact lenses. Because lens material may tend to stick to itself and/or to the lens package, packaging solutions for blister-packs have sometimes been formulated to reduce or eliminate lens folding and sticking. Additionally, polymeric components have been included in packaging solutions to improve comfort of a contact lens when worn. As examples, polyvinyl alcohol (PVA) has been used in contact lens packaging solutions, and U.S. Pat. No. 6,440,366 discloses contact lens packaging solutions comprising polyethylene oxide (PEO)/polypropylene oxide (PPO) block copolymers, especially poloxamers or poloxamines.

It is highly desirable that contact lenses be as comfortable as possible for wearers. Some contact lens wearers experience dryness or eye irritation throughout the day and particularly towards the end of the day. Some contact lens wearers experience discomfort when the lens is initially inserted in the eye.

A drawback to some polymeric components for contact lens packaging solutions is that the polymeric component may affect visual acuity. For example, especially at initial insertion of the lens, a wearer may experience blurred vision.

Accordingly, it would be desirable to provide a packaging system for contact lenses such that the lenses would be more comfortable to wear, without compromising visual acuity.

This invention provides an aqueous solution for the packaging and storage of a contact lens. The packaging solution comprises hydroxypropyl methylcellulose (HPMC) and has an osmolality of at least about 200 mOsm/kg and a pH in the range of about 6 to about 8.

This invention also provides a method comprising: (a) immersing a contact lens in a package with the aqueous solution comprising hydroxypropyl methylcellulose; (b) sealing the solution and the contact lens within the package; and (c) sterilizing the packaged solution and device. The method may include hermetically sealing the contact lens and the solution in the package and heat sterilizing the package contents.

Additionally, this invention provides a combination comprising a contact lens and an aqueous solution in a sealed container, wherein the solution comprises hydroxypropyl methylcellulose and the solution has an osmolality of at least about 200 mOsm/kg and a pH in the range of 6 to 8.

The contact lens is preferably a silicone hydrogel contact lens, and may be made of an ionic copolymeric material, including a Group III or IV contact lens.

The solution preferably has a viscosity in the range of 0.5 to 5 cps. According to preferred embodiments, the solution has an osmolality in the range of 250 to 400 mOsm/kg, a pH in the range of 7.0 to 7.5, and/or a viscosity in the range of 1 to 3 cps.

According to preferred embodiments, the concentration of HPMC is 0.05 to 5 weight percent, more preferably 0.1 to 0.4 weight percent. According to preferred embodiments, the hydroxypropyl methylcellulose has a viscosity (at 20oC and at 2 weight % in water) of no greater than 50 cps, more preferably no greater than 25 cps.

The solution may further comprise a buffer, such as a borate buffer, and NaCl. The solution preferably does not contain an effective disinfecting amount of a disinfecting agent or a germicide compound.

The solution may consist essentially of hydroxypropyl methylcellulose, a borate buffer and NaCl.

The solution may consist of hydroxypropyl methylcellulose, a buffer, NaCl, water, and an optional chelating agent. A preferred embodiment is a solution consisting of: 0.05 to 0.5 weight percent hydroxypropyl methylcellulose; 0.05 to 2.5 weight percent buffer; 0.01 to 2.5 weight percent NaCl; 0 to 1 weight percent chelating agent; and water.

Another preferred embodiment is a solution comprising: 0.05 to 0.5 weight percent hydroxypropyl methylcellulose; 0.05 to 2.5 weight percent buffer; and 0.01 to 2.5 weight percent NaCl; and the solution has an osmolality in the range of 250 to 400 mOsm/kg, a pH in the range of 7.0 to 7.5, and a viscosity in the range of 1 to 3 cps.