Abstract: A process for sterilizing a polysaccharide composition containing chitosan, a chitosan derivative or a chitin derivative without substantially degrading the polysaccharide. The process has the steps of blending the polysaccharide in a solvent to form a solution or suspension; sterilizing the solution or suspension; dissolving suspended particles, if present; and then aseptically adjusting the pH of the sterilized solution. There is additionally provided a polyol stabilizing agent suitable for the polysaccharide composition.

Abstract: Copolymers formed from dimethacrylates of polyalkylene glycols and vinylic reactive silicones having up to 20 silicon atoms in the substantial absence of additional cross-linking agents. The copolymers may include a hydrophilicity-modifying monomer. The preferred silicon is TRIS (i.e., 3-methacryloxypropyl tris(trimethylsiloxy) silane), while the preferred polyalkylene glycol is polypropylene glycol dimethacrylate. The copolymers are especially suited to use in the fabrication of soft contact lenses because of the good durability and high oxygen permeability and transmissibility. Oxygen transmissibilities of greater than 70 barrers/mm are preferred.

Abstract: An ophthalmic lens suited for extended-wear for periods of at least one day on the eye without a clinically significant amount of corneal swelling and without substantial wearer discomfort. The lens has a balance of oxygen permeability and ion or water permeability, with the ion or water permeability being sufficient to provide good on-eye movement, such that a good tear exchange occurs between the lens and the eye. A preferred lens is a copolymerization product of a oxyperm macromer and an ionoperm monomer. The invention encompasses extended wear contact lenses, which include a core having oxygen transmission and ion transmission pathways extending from the inner surface to the outer surface.

Abstract: Contact lenses, especially toric and bifocal, which are rotationally stabilized and methods of stabilizing contact lenses. Contact lenses are stabilized, with respect to rotation while in place on the eye, by providing the lenses with a non-circular shape. In a preferred embodiment, a toric contact lens is rotationally stabilized by providing the lens with an oval shape. Also disclosed are methods of providing non-circular lenses with appropriate shapes for proper fit to a patient's eye.

Abstract: An article treatment system which provides improved solution mixing and concentration uniformity. The treatment system includes a container, a closure and a channel for guiding fluid flow. The treatment system is especially advantageous for use with effervescent tablets and for use in treating contact lenses. Cleaning and disinfecting of articles is improved by use of a tubular channel which guides upwardly gas and other components released from an effervescent tablet which is located at the bottom of the treatment container. The upward central flow through the channel induces a downward flow between the container walls, the exterior walls of the channel, and the article-retaining means and towards the bottom of the container.

Abstract: A preservative for ophthalmic solutions having an active ingredient is provided, having a hydrogen peroxide content of about 0.001% to about 0.10% by weight; and diethylene triamine penta(methylene phosphonic acid) or a physiologically compatible salt thereof, present at about 0.002% to 0.03% by weight and/or 0.005% to about 0.20% by weight of 1-hydroxyethylidene-1,1-diphosphonic acid, or physiologically acceptable salt thereof.

Abstract: Corneal onlays for use in surgical implantation into or onto the cornea of a mammal are described. The corneal onlays according to the invention have an optical axis region with optical characteristics which provide visual acuity therethrough and are comprised of a non-biodegradable non-hydrogel ocularly biocompatible material, characterized in that the onlay has a porosity sufficient to allow passage therethrough of tissue fluid components having a molecular fluid weight greater than 10,000 daltons so as to provide for a flux of tissue fluid between cells anterior of the implanted onlay and cells posterior thereof. The porosity of the optical axis region is such that it allows the flux of tissue fluid components whilst excluding ingrowth of ocular tissue. The onlay is further characterized by being adapted for epithelial recolonization.

Abstract: The present invention describes novel statistical copolymers and the preparation and possible uses thereof. Copolymers are described that are water-soluble and cross-linkable and that comprise the copolymerisation product of a monomer mixture consisting substantially of a vinyl lactam (a) and at least one further vinyl monomer (b) of a different type selected from the group consisting of hydrophobic, hydrophilic and functional vinyl monomers, wherein the monomers are present in the copolymer in the form of statistically distributed building blocks, and, if a functional vinyl monomer is present as a building block in the copolymer, that building block is, where appropriate, modified with a reactive vinyl monomer (c), the reactive vinyl monomer (c) being linked to a building block of a functional vinyl monomer with retention of its vinylic group and with the formation of a covalent bond.

Abstract: The present invention relates to polymerisable derivatives of carbohydrates comprising a compound of formula (I)R.sup.1 --(COO--Alk).sub.m -(OCONH--R).sub.n -(NHCO).sub.p Y--Z (I)whereinR.sup.1 is a radically polymerisable hydrocarbon group; m, n and p are 0 or 1; Alk is alkylene having up to 10 carbon atoms; R is a diradical, having up to 20 carbon atoms, of an organic diisocyanate; Z is a monovalent radical, minus a single hydroxy group, of a mono-, di- or tri-saccharide, of an oligosaccharide, of a cyclodextrin (CD) or of an anhydrosaccharide; and Y is --O-- or --NH--; with the proviso that when p is zero, m and n are also zero and Y is --NH--; to homopolymers, copolymers, block copolymers, graft copolymers and polymeric networks thereof, to moulded articles, for example contact lenses or biomedicinal articles, comprising the mentioned polymers, as well as to processes for the preparation of the mentioned polymers and articles.

Abstract: Compositions and methods for reducing the decomposition rate of polymeric bioadhesives and viscosity enhancers, such as poly(acrylic acids). The compositions include at least one strong, stable chelating agent, preferably an organophosphorous compound such as diethylene triamine penta(methylene phosphonic acid). These biocompatible compositions are especially useful in the ophthalmic field.

Abstract: A package containing an aqueous drug composition containing an insoluble resin comprising benzalkonium salt units in an amount sufficient to inhibit growth of microbes in said aqueous drug solution. Typically, the insoluble resin is a polymer having repeating units of the formula:--?CH.sub.2 --CH(Ar)!--wherein Ar=a group of the formula:-Phe-CH.sub.2 --N.sup.+ (CH.sub.3).sub.2 R X.sup.-wherein R=long chain alkyl such as C.sub.8-18 alkyl, Phe=phenylene, and X.sup.- is a pharmaceutically acceptable counter anion such as Cl.sup.-.

Abstract: An apparatus and method for uniformly contacting an article with a treatment solution. Preferred embodiments are methods of uniformly tinting of contact lenses or uniformly surface modifying contact lenses. The method involves suspending the lens in the treatment solution by application of fluid flow, preferably sinusoidal or pulsed, in a direction opposite the stagnant force (i.e., sum of buoyancy and gravity forces) on the article. The fluid flow prevents the lens from contacting the container structure for periods sufficient to cause non-uniform treatment conditions, while continuously mixing the treatment solution to maintain uniform concentrations throughout.

Abstract: An appliance for sterilizing contact lenses or the like includes a reaction vessel for containing the lenses in sterilizing contact with hydrogen peroxide solution and two catalytic elements for decomposing the hydrogen peroxide during the lens sterilization. The first catalytic element decomposes a portion of the initial concentration of hydrogen peroxide in the solution during the lens sterilization, and the second catalytic element accelerates combined decomposition of the reduced concentration of hydrogen peroxide in the solution resulting from decomposition by the first catalytic element, in order to achieve sufficiently reduced terminal hydrogen peroxide concentration at completion of the lens sterilization for safe contact by the eyes of a wearer with residues of hydrogen peroxide at the terminal concentration which may adhere to the sterilized lenses.

Abstract: Apparatus is provided for use in the sterilization of contact lenses or the like, wherein lenses are disposed within a sterilizing solution contained within a reaction vessel, which sterilizing solution is capable of being decomposed through contact with a catalytic agent. The apparatus comprises a reaction vessel capable of containing a sterilizing solution and comprising a container portion, a cover and structure for supporting an article in contact with sterilizing solution in the container. Further structure is provided for mounting a catalytic agent on the supporting structure such that the catalytic agent is removable for replacement by a user as the catalytic agent becomes exhausted in use.

Abstract: Contact lenses are disinfected in a method including treating the contact lenses with an aqueous system of hydrogen peroxide in the presence of a hydrogen peroxide decomposition catalyst, and heating the system in order to accelerate decomposition of the hydrogen peroxide. In a preferred embodiment of the method, the initial concentration of hydrogen peroxide in the system is approximately 3-4% and the heating promotes decomposition of the hydrogen peroxide to a concentration of 50 parts per million or less within six hours following initial contact of catalyst with the system. The catalytic decomposition can be performed in a conventional lens sterilization vessel which is inserted within a heated receptacle to heat the reaction vessel and the contained sterilization system. The heated receptacle controls the temperature of the inserted vessel and sterilization system within a range of approximately 60.degree.-80.degree. C.

Abstract: An appliance for disinfecting contact lenses or the like wherein the lenses are disposed within a disinfecting solution which liberates the gas during the disinfecting action, includes a container body for immersion of the lenses within the disinfecting solution and a removable cap closing the container body. The appliance further includes a normally closed vent conduit for passage of the pressurized affluent gas from the container body through the cap, and within the vent conduit is a check valve including a disc member having a slit therethrough which opens for vent discharge of the gas with sufficient pressure on the disc exerted by the gas during passage through the vent conduit, after which the slit recloses to vent any subsequent leakage of the solution therethrough.

Abstract: Apparatus is provided for use in the sterilization of contact lenses or the like, wherein lenses are disposed within a sterilizing solution contained within a reaction vessel, which sterilizing solution is capable of being decomposed through contact with a catalytic agent. The apparatus comprises a reaction vessel capable of containing a sterilizing solution and comprising a container portion, a cover and structure for supporting an article in contact with sterilizing solution in the container. Further structure is provided for mounting a catalytic agent on the supporting structure such that the catalytic agent is removable for replacement by a user as the catalytic agent becomes exhausted in use.

Abstract: An appliance for sterilizing contact lenses or the like includes a reaction vessel for containing the lenses in sterilizing contact with hydrogen peroxide solution and two catalytic elements for decomposing the hydrogen peroxide during the lens sterilization. The first catalytic element decomposes a portion of the initial concentration of hydrogen peroxide in the solution during the lens sterilization, and the second catalytic element accelerates combined decomposition of the reduced concentration of hydrogen peroxide in the solution resulting from decomposition by the first catalytic element, in order to achieve sufficiently reduced terminal hydrogen peroxide concentration at completion of the lens sterilization for safe contact by the eyes of a wearer with residues of hydrogen peroxide at the terminal concentration which may adhere to the sterilized lenses.

Abstract: An appliance for containing and venting fluid, typically for disinfecting contact lenses, includes a container body which has an access opening and a removable closure for the opening. A gasket is seated to form a normally liquid-tight seal between the container body and the closure, and the gasket means has a composition which is sufficiently resilient to at least partially deflect and unseat from the container body upon exertion against the gasket of elevated gas pressure developed within the container, for example, during a disinfection process. The pressurized gas can then be vented past the unseated gasket which forms a vent passageway between the closure and the container body, after which venting the gasket redeflects to reseat and seal against the container body to prevent any subsequent leakage of fluid from the container body.