Abstract: An ultrathin, permselective membrane for use in gas or vapor separations. The membrane comprises a permselective layer of ethylcellulose in combination with one or more permselective layers of poly(4-methylpentene-1). The permselective membrane is preferably coated onto a microporous substrate, such as an asymmetric Loeb-Sourirajan type membrane. The resulting membrane has high gas fluxes and selectivities, and can be used, for example, to separate oxygen and nitrogen; hydrogen sulfide from nitrogen, methane or carbon dioxide; hydrogen from nitrogen; sulfur dioxide or ammonia from nitrogen; or water vapor from air. A method of preparing such a membrane is also provided, as is a gas separation process using the membrane.

Abstract: A process for separating ethane and other higher hydrocarbons from a natural or produced gas stream, having methane as its major constituent. A rubbery permselective membrane, having a propane/methane selectivity of 8 or above, is contacted on its feed side with a gas mixture typically containing methane, ethane, propane, butane, and small amounts of other hydrocarbons, water vapor, hydrogen sulfide and carbon dioxide. Carbon dioxide, water vapor, ethane and the other higher hydrocarbons permeate preferentially through the membrane, and the retentate stream is correspondingly enriched in methane.

Abstract: An ultrathin, high-flux composite membrane for use in gas separation. The membrane comprises a metal layer, typically 500.ANG. or less thick on a microporous support. The support may be as asymmetric Loeb-Sourirajan type membrane or a two-layer composite of a microporous substrate with a very thin sealing layer. The support gives mechanical strength to the membrane but does not contribute significantly to the selectivity. Optionally the metal layer may be overcoated with a second polymeric sealing layer to plug any defects and to protect the fragile surface from mechanical damage. The membrane is particularly useful in the purfication of hydrogen.

Abstract: A controlled release transdermal delivery system for nicotine administration. The system comprises an impermeable backing layer, a polyurethane matrix layer containing between about 5 wt % and 50 wt % nicotine, and an adhesive skin-contacting layer. The system is designed to administer nicotine for smoking cessation therapy or other uses over a period of 24 hours or more.

Abstract: A portable controlled release osmotic infusion device, which can be activated on demand by the user, comprising a rigid housing containing:a. a fluid-imbibing assembly, comprising a solvent-containing chamber and a solute-containing chamber; the two chambers separated by a rigid semipermeable membrane covered by a thin taut foil seal,b. a drug-containing chamber separated from the fluid-imbibing assembly by a leakproof impermeable elastic diaphragm, which expands into the drug-containing chamber in use and drives the drug through a dispersing orifice at a steady rate, andc. an activating device which ruptures the foil seal described in (a) above and initiates the osmotic action of the device.The osmotic device is filled with drug in solution or suspended form during manufacture and can be stored without deterioration of the contents for prolonged periods of time.

Abstract: A controlled release drug delivery system for placement in the periodontal pocket. The system comprises a plurality of drug-containing microparticles or microcapsules, between 10 and 500 microns in size, suspended in a pharmaceutically acceptable carrier medium, and is capable of maintaining an effective level of drug in the periodontal pocket for a period of 1 to 30 days.