Abstract: An adhesive composition or structure is proposed for use in skin application, e.g. drug delivery wound care, or for attaching devices to collect body waste to the wearer. The composition comprises (a) a polymer or mixture of polymers which act as a pressure-sensitive adhesive present in an amount 20-60 parts by weight of the adhesive composition; and (b) a water-swellable polymer present in an amount 20-80 parts by weight of the adhesive composition. The polymer is one which will absorb from 50 to 500 grams of pure water per 100 grams of water-swellable polymer.Additionally there may be present up to 30 parts by weight (of the adhesive composition) of a water-soluble polymer.The water-swellable polymer may be provided as a coating on non-water-soluble and non-water-swellable fibers which limit swelling of the coating to be radial of the fibers. By arranging or aligning the fibers, the direction of swelling of the composition or structure can be controlled.

Abstract: In a hypodermic syringe of the type comprising a chamber for liquid to be injected and a needle having a point for injection of the liquid, the syringe additionally includes, in contact with the liquid flow path through the syringe, a pre-stressed hydrophilic insert that, on hydration by contact with liquid, expands to block the flow path. The syringe is thus self-blocking; it can also be self-blunting, thus prevent reuse.

Abstract: Hydrophilic polymers of the type suitable for use in making contact lenses and having a wide range of controllable properties including strength and gas permeability are formed from acrylonitrile or methyl methacrylate or an analogue thereof, 1-vinyl-2-pyrrolidinone and an appropriate amount of a cross-linking agent. Contact lenses (3) having an interferometric pattern thereon are also disclosed.

Abstract: A polymeric composition is disclosed which has sealant and preferably also adhesive properties and which is suitable for use as a protective dressing for application to the skin. The composition comprises a chemically cross-linked hydrophilic polymer and a support matrix such as a high molecular weight hydrophobic polymer. The hydrophilic polymer is a water-swellable polymer which absorbs or adsorbs water but which is water-insoluble. The composition preferably includes a tackifyer which may be provided by a low molecular weight fraction of a hydrophobic matrix or by a distinct adhesive component such as a gum or a low molecular weight polymer. The composition is particularly suitable for use as a sealing ring in conjunction with a post-surgical drainage appliance wherein the hydrophilic polymer is incorporated in a form such as to provide a transmission system for liquid.

Abstract: Hydrophilic polymers of the type suitable for use in making contact lenses and having a wide range of controllable properties including strength and gas permeability are formed from acrylonitrile or methyl methacrylate or an analogue thereof, 1-vinyl-2-pyrrolidinone and an appropriate amount of a cross-linking agent. Contact lenses (3) having an interferometric pattern thereon are also disclosed.

Abstract: A shaped polymeric composition, for surgical or dental use, can absorb liquid and thereby expand or contract in one direction, substantially without similar expansion or contraction in another direction. Embodiments of the invention are breast implants, tapered dental inserts, and tubular bodies for use as nerve approximation sheaths.

Abstract: A method for modifying the properties of solid polymers in which a polymerizable substance is introduced into the polymer to be modified and is then polymerized. The method allows solid polymers having desirable combinations of properties not otherwise obtainable to be made and permits accurate control over the properties. The method also permits the making of solid polymer articles having different properties in different parts of their bulk and is especially valuable in making hydrophilic polymers of well controlled properties.