Abstract: An iontophoretic device having a two-layer active electrode element is disclosed. The active element is composed of overlapping skin contact hydrogel and carrier layers. The carrier layer contains dispersed or dissolved active agent. The active electrode element maintains the active agent in stable form and permits efficient transport of the active agent to the host. Also disclosed is an iontophoretic device having a single layer active electrode element. The single layer is a hydrogel as manufactured or substantially dry and capable of being hydrated before use. The skin contact hydrogel of the two-layer active electrode element preferably.

Abstract: Articles having a graft polymer with a net ionic charge bonded to a polymeric substrate surface provide an improved method for administering a bioactive agent having a net ionic charge. The [articles are] method is especially useful [as] for thromboresistant and/or antimicrobial medical devices.

Abstract: A polymeric, amphoteric hydrogel for use in medical devices and medical devices using the hydrogel. The hydrogel has a first polymer repeating unit having a acid group and a second polymer repeating unit having a base group such that the acid groups and base groups are present in the hydrogel in amounts effective to provide a hydrogel with a strong, amphoteric, nonmobile ionic structure. For example, the hydrogel can be a copolymer of 2-acrylamido-2-methylpropane sulfonic acid and methacrylamido-propyl-trimethylammonium hydroxide. The hydrogel can be an adhesive used to adhere medical devices to the skin of a patient. It can be particularly useful in drug delivery applications such as in iontophoresis devices.

Abstract: Articles comprised of bioactive agents coupled to or repelled by a graft polymer (made, for example, from monomers such as N-(3-aminopropyl) methacrylamide hydrochloride (APMA), 2-acrylamido-2-methylpropane sulfonic acid (AMPS), acrylamide (AAm), and acrylic acid (AA)) which is in turn bonded to a polymeric substrate surface. The articles are useful as thromboresistant and/or antimicrobial medical devices.

Abstract: An iontophoretic device having a two-layer active electrode element is disclosed. The active element is composed of overlapping skin contact hydrogel and carrier layers. The carrier layer contains dispersed or dissolved active agent. The active electrode element maintains the active agent in stable form and permits efficient transport of the active agent to the host. Also disclosed is an iontophoretic device having a single layer active electrode element. The single layer is a hydrogel as manufactured or substantially dry and capable of being hydrated before use. The skin contact hydrogel of the two-layer active electrode element preferably.

Abstract: The present invention provides resistance to degradation from environmental stress cracking (ESC) and metal ion induced oxidation (MIO) for implantable, flexible pacing lead insulators having a body of polyether polyurethane elastomer material. A thin layer of a second polyurethane elastomer is applied as an overcoat to the lead insulator body. The second polyurethane is more resistant to ESC and MIO than the elastomer comprising the body of the insulator. Because ESC and MIO are surface phenomina, only a thin layer of the second material is required and the mechanical properties of the base material will determine the overall mechanical properties of the lead insulator.

Abstract: The present invention provides resistance to degradation from environmental stress cracking (ESC) and metal ion induced oxidation (MIO) for implantable, flexible pacing lead insulators having a body of polyether polyurethane elastomer material. A thin layer of a second polyurethane elastomer is applied as an overcoat to the lead insulator body. The second polyurethane is more resistant to ESC and MIO than the elastomer comprising the body of the insulator. Because ESC and MIO are surface phenomina, only a thin layer of the second material is required and the mechanical properties of the base material will determine the overall mechanical properties of the lead insulator.

Abstract: Articles comprised of bioactive agents coupled to or repelled by a graft polymer (made, for example, from monomers such as N-(3-aminopropyl) methacrylamide hydrochloride (APMA), 2-acrylamido-2-methylpropane sulfonic acid (AMPS), acrylamide (AAm)m and acrylic acid (AA)) which is in turn bonded to a polymeric substrate surface. The articles are useful as thromboresistant and/or antimicrobial medical devices.

Abstract: An implantable multi-lumen, multi-conductor lead for use with an implantable medical device. The completed lead is an assembly of a polymeric lead body with several coiled conductors inserted into the lead body. The lead body includes several lumens having a generally rounded-corner triangular or "pie-shaped" cross-section. The conductors do not fill the lumens, and only contact the inner walls of the lumens at discrete points, rather than for extended sections of or all of the circumference of the conductors. Preferably the coils are sized so that they fit loosely within the lumens.

Abstract: An improved biomedical appliance having disposed on a skin-contacting, operant portion thereof, a film or layer of a skin compatible, tacky, pressure sensitive polymeric adhesive, the reaction product consisting of at least one fatty acid dimer based or derived component and a suitable co-reactant. Electrodes, surgical tapes, TENS devices and iontophoresis devices employing the adhesive are disclosed.

Abstract: An ionic substance is mixed with a polar, non-ionic adhesive to form an electrode for use in the iontophoretic introduction of the ionic substance into a body. The electrode may be formed as a sheet of the mixture of a size and shape suitable for attachment to the electrode plate of an iontophoretic current generator. The mixture may be incorporated in an electrode as a means for holding the ionic substance, a means for attaching the electrode to the body, a means for attaching the iontophoretic current generator to the body, or a means for conducting the ionic current into the body. The electrode may also be employed in combination with an electrical stimulator to provide for simultaneous electrical stimulation and iontophoretic drug administration to the body.

Abstract: An improved hydrogel adhesive, particularly adapted for adhesion and contact to tissue. It is especially useful in attaching electrical leads to tissue, for example in attaching pacemaker leads to the heart, interiorly or exteriorly.

Abstract: Reaction grade 2-acrylamido-2-methylpropane sulfonic acid is refined by mildly heating a slurry-like suspension formed of the acid and a liquid monohydric alcohol, recovering the acid from the alcohol and subsequently drying it.

Abstract: Novel, hydrophilic, skin-compatible, pressure sensitive, solid, adhesive gel hydrogel composition comprising 25 to 50 weight percent polyvinyl pyrolidone (PVP) preferably having a molecular weight in the range of about 100,000 to 600,000, 2 to 5 weight percent polyvinyl alcohol (PVA) preferably having a molecular weight in the range of about 150,000 to 300,000, about 5 to about 40 weight percent humectant, about 3 to about 50 weight percent water, about 0 to about 50 weight percent of an ionic species. In a preferred aspect, the composition of the invention is utilized in an iontophoresis device to provide a hydrophilic gel matrix from which a drug is iontophoretically delivered.

Abstract: An improved method for producing ion-selective membranes having a desired shape and of a desired plastic, for incorporation in ion-sensing electrodes, and the electrodes incorporating these membranes. This method allows the use of preformed polymeric members having the desired shape to produce ion-selective membranes, allowing simplified production of ion-sensing electrodes, as well as combination ion-sensing and reference electrodes.

Abstract: A method of preparing a C.sub.21 dicarboxylic acid using crystalline clay as a catalyst.

Abstract: Copolyamides of a C.sub.19 diacid, a coacid selected from isophthalic acid, terephthalic acid, alkyl substituted isophthalic acid or esters thereof and a diamine selected from hexamethylene diamine and trimethyl hexamethylene diamine.

Abstract: Polyamids of a C.sub.19 diacid and certain cyclical diamine which are excellent engineering plastics.