Drug – bio-affecting and body treating compositions – Solid synthetic organic polymer as designated organic active... – Aftertreated polymer
Reexamination Certificate
1999-07-15
2001-02-20
Fay, Zohreh (Department: 1614)
Drug, bio-affecting and body treating compositions
Solid synthetic organic polymer as designated organic active...
Aftertreated polymer
C514S912000
Reexamination Certificate
active
06190651
ABSTRACT:
The present invention relates to a solution for preserving contact lenses for shipping and a method for preserving contact lenses for shipping employing it.
Most of conventional contact lenses, particularly oxygen-permeable hard contact lenses contain silicon components. Accordingly, the surface of the contact lenses tends to be hydrophobic, and wettability is poor when they are firstly worn, whereby comfortableness in wearing tends to be poor, or satisfactory vision is less likely to be obtained. Accordingly, to keep the surface water wettability of said oxygen-permeable hard contact lenses, after they are produced until they are worn by patients, they are preserved as wet for shipping, by e.g. subjecting them to a surface treatment, or preliminarily immersing them in a preserving solution for shipping such as physiological saline.
However, in the case where contact lenses are preserved as wet for shipping by using e.g. physiological saline, there is a possibility that the base curve which is one of important specifications of contact lenses may change during the process for shipping.
Further, a surfactant is usually incorporated to many of conventional preserving solutions for shipping. Accordingly, a change in size of a contact lens such as the change in the base curve is likely to take place.
Under these circumstances, the present invention has been made, and it is an object of the present invention to provide a solution for preserving contact lenses for shipping, which significantly reduces a change in the base curve while contact lenses, particularly oxygen-permeable contact lenses, are preserved as wet for shipping, and a method for preserving contact lenses for shipping employing it.
The present invention relates to (1) a solution for preserving contact lenses for shipping, which comprises a polyvinyl pyrrolidone having a weight average molecular weight of from 500 to 200,000, and which contains no surfactant; (2) a solution for preserving contact lenses for shipping, which comprises from 0.2 to 3 w/v % of a polyvinyl pyrrolidone having a weight average molecular weight of from 500 to 200,000 and a K value of from 20 to 100, from 0.000005 to 0.0002 w/v % of a polyhexamethylene biguanide and from 0.02 to 0.3 w/v % of ethylenediaminetetraacetic acid, sodium ethylenediaminetetraacetate, or a hydrate of sodium ethylenediaminetetraacetate, and which contains no surfactant; and (3) a method for preserving contact lenses for shipping, which comprises immersing contact lenses in the above-mentioned solution (1) or (2).
Now, the present invention will be described in detail with reference to the preferred embodiments.
As mentioned above, the solution for preserving contact lenses for shipping of the present invention comprises a polyvinyl pyrrolidone having a weight average molecular weight of from 500 to 200,000, and contains no surfactant.
For the solution for preserving contact lenses for shipping of the present invention, a polyvinyl pyrrolidone is employed as an effective component to reduce the change in the base curve of a contact lens while the lens is preserved as wet for shipping.
The weight average molecular weight of the polyvinyl pyrrolidone is at least 500, preferably at least 1,000, considering that a certain level of molecular weight is required to obtain an adequate effect of stabilizing the base curve. Further, it is at most 200,000, preferably at most 150,000, considering a possibility that the solubility in a medium such as water will decrease, whereby an uniform solution for preserving contact lenses for shipping is less likely to be obtained, and considering a problem in handling efficiency due to increase in the viscosity.
The K value of the polyvinyl pyrrolidone as described in Japan Pharmacopoeia is at least 20, preferably at least 25, to obtain an adequate effect of stabilizing the base curve of a contact lens. Further, it is at most 100, preferably at most 90, considering a possibility that the solubility in a medium such as water will decrease, whereby an uniform solution for preserving contact lenses for shipping is less likely to be obtained, and considering a problem in handling efficiency due to increase in the viscosity. As a polyvinyl pyrrolidone having a K value of such a range, polyvinyl pyrrolidone K25, polyvinyl pyrrolidone K30 or polyvinyl pyrrolidone K90 may, for example, be mentioned.
The amount of the polyvinyl pyrrolidone in the solution for preserving contact lenses for shipping is at least 0.1 w/v % , preferably at least 0.2 w/v %, to obtain an adequate effect of reducing the change in the base curve of a contact lens while it is preserved as wet for shipping, by employing said polyvinyl pyrrolidone. Further, it is at most 10 w/v %, preferably at most 3 w/v %, to eliminate a possibility that the viscosity of the solution for preserving contact lenses for shipping will increase too much, whereby such a problem in handling may result that the contact lens is likely to get dirty as dried.
The solution for preserving contact lenses for shipping of the present invention preferably contains e.g. a preservative or a chelating agent in addition to the above-mentioned polyvinyl pyrrolidone.
The preservative serves to prevent contamination of the solution for preserving contact lenses for shipping by bacteria, and to prevent contamination of a contact lens during preservation for shipping.
The preservative is not particularly limited so long as it is ophthalmologically acceptable. It may, for example, be a compound which contains at least one member selected from the group consisting of a quaternary ammonium group, a biguanide group and a quaternary phosphonium group. Representative examples of said compound and other examples include a compound such as a polymer (I) having repeating units of the formula (I):
wherein Z is a bivalent organic group such as a C
2-18
polyoxyalkylene group, and f is an integer of at least 3, provided that the plurality of Z may be the same or different in the polymer, a polymer (II) having repeating units of the formula (II):
a polymer (III) having repeating units of the formula (III):
wherein R
1
is a hydrogen atom or a methyl group, R
2
is a C
1-8
alkylene group, R
3
is a C
1-18
alkyl group, and X
1
is a halogen atom such as a chlorine atom, a bromine atom or an iodine atom, and a polymer (IV) having repeating units of the formula (IV):
wherein R
4
is a hydrogen atom or a methyl group, R
5
is a C
1-8
alkylene group, R
6
is a C
1-18
alkyl group, and X
2
is a halogen atom such as a chlorine atom, a bromine atom or an iodine atom, a mercury type preservative such as phenylmercury nitrate, phenylmercury acetate and thimerosal; a surfactant type preservative such as benzalkonium chloride and pyridinium bromide; an alcohol type preservative such as chlorohexyzine, polyhexamethylene biguanide and chlorobutanol; methylparaben, propylparaben, dimethylol dimethylhydantoin, imidazolinium urea; and a copolymer of e.g. a monomer (V) of the formula (V):
wherein R
1
is a hydrogen atom or a methyl group, R
2
is a C
1-8
alkylene group, R
3
is a C
1-18
alkyl group, and X
1
is a halogen atom such as a chlorine atom, a bromine atom or an iodine atom, or a monomer (VI) of the formula (VI):
wherein R
4
is a hydrogen atom or a methyl group, R
5
is a C
1-8
alkylene group, R
6
is a C
1-18
alkyl group, and X
2
is a halogen atom such as a chlorine atom, a bromine atom or an iodine atom, with a water-soluble monomer of e.g. a hydroxyalkyl(meth)acrylate such as hydroxymethyl(meth)acrylate, hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate or hydroxybutyl(meth)acrylate.
Further, various types of biguanide derivatives are commercially available, and in the present invention, the preservative may be suitably selected from these commercially available biguanide derivatives.
In view of a higher effect of preventing contamination by bacteria, such being effective, among the above-mentioned preservatives, at least one compound selected from the group consisting of the polymer (I), the polymer (II), the polymer
Matano Yutaka
Nakada Kazuhiko
Fay Zohreh
Menicon Co. Ltd.
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
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