United States Patent:  6,090,403

Assignee:  LecTec Corporation (Minnetonka, MN)

Filed:  August 17, 1998

A vaporizable decongestant is supported and stabilized on a flexible foraminous carrier composed typically of open-cell plastic foam, cloth or other fibrous material such as nonwoven fabric. The term "foraminous" herein is intended to refer to a substance or medium containing minute openings or perforated by many minute apertures. The decongestant is placed on the surfaces within the interstices and minute apertures or on fibers from which the foraminous carrier is formed. Vaporization of the inhalable decongestant is facilitated by providing the potential for greatly increasing its exposed surface area. Distributing the decongestant composition over the large, expanded surface within the foraminous carrier is beneficial in enhancing both the volatilization and evaporation of the decongestant agent. It also prolongs the useful life of the product. Once vaporized, the aromatic decongestant is available for natural inhalation through the nose or mouth to help relieve one or more of the symptoms of cough, colds, nasal or chest congestion and related symptoms. The foraminous carrier is preferably provided in the form of a patch or sheet that is bonded to the skin to serve as a supporting base for the active decongestant agent. The patch defining the carrier is typically adhesively bonded to the upper part of the body, e.g. on the face, neck or chest, in a location where the decongestant is liberated into the air and can be inhaled through the mouth or nose.

SUMMARY OF THE INVENTION

The present invention provides a decongestant, preferably an aromatic, vaporizable decongestant supported on a foraminous carrier composed typically of an open-cell plastic foam, perforated plastic film, cloth or other fibrous material such as nonwoven fabric. The term "foraminous" herein is intended to refer to a substance or medium containing minute openings or perforated by many minute apertures. To form such a product in accordance with the present invention, an inhalable decongestant is placed on surfaces within the interstices and minute apertures or on fibers of which the foraminous carrier is composed. In this way vaporization of the inhalable decongestant is facilitated by providing the potential for greatly increasing its exposed surface area. Thus, distributing the decongestant composition over the large, expanded surface within the foraminous carrier is beneficial in enhancing both the volatilization and evaporation of the decongestant agent. It also helps to prolong the useful life of the product. Once vaporized, the aromatic decongestant is available for natural inhalation through the nose or mouth to help relieve one or more of the symptoms of cough, colds, nasal or chest congestion and related symptoms. The foraminous carrier is preferably provided in the form of a patch or sheet that is bonded to the skin and acts as a supporting base for the active decongestant agent.

The patch defining the carrier is placed on the upper part of the body, typically on the face, neck or chest, in a location where the decongestant is liberated into the air and can be inhaled through the mouth or nose. The patch which serves as a carrier for the decongestant is bonded to the skin either through the provision of an adhesive on the lower surface of the patch or by means of a separate piece of pressure-sensitive adhesive tape or adhesive coating, either surrounding the carrier or applied along the edges of the lower surface of the carrier.

The decongestant can be applied to the foraminous carrier in various ways. For example, by spraying, roll-coating, dipping, knife-coating, or calendering. If desired, the decongestant agent can extend substantially through the entire thickness of the carrier sheet. It is preferred that the entire patch be non-occlusive, i.e. capable of allowing moisture from the skin to diffuse outwardly and escape through the upper surface of the patch. However, if desired, the foraminous carrier sheet can be provided as an upper layer of the patch which is bonded to a non-porous sheet material such as a sheet of plastic film having a separate layer of pressure-sensitive adhesive on its lower surface for bonding the patch to the skin. In this case, the patch as a whole is occlusive and as such will not allow moisture to escape from the skin.

A variety of well known therapeutic agents that have a decongestant or analgesic action can be employed. Examples include oil of wintergreen, menthol, thymol, camphor, oil of peppermint, eucalyptus oil, phenylephrine hydrochloride, pheniramine maleate, benzalkonium chloride, methyl salicylate, pseudoephedrine hydrochloride, oxymetazoline hydrochloride, xylometazoline hydrochloride, methazoline hydrochloride, epinephrine, spirits of turpentine, ephedra (ma huang), coltsfoot (Tussilago farfara L.), ginger (Zingiber officinale), naphazoline hydrochloride, and other decongestants known in the art. We have found that the turpentine, because of its volatility, appears to help co-evaporate other active decongestant agents. To prepare the patch, the decongestant, i.e. the therapeutic agent, is preferably dispersed in a vehicle to form an ointment that can either be hydrophilic or hydrophobic in nature. A typical hydrophilic vehicle preferably includes a thickener comprising a water-dispersible or water-swellable natural or synthetic polymer. The thickener raises the viscosity to a level that resists spreading and can, if desired, cause the ointment to set-up as an elastic solid. A hydrophilic ointment also contains water and a humectant such as a polyhydric alcohol. Typical hydrophobic vehicles comprise mineral oil or petroleum jelly, or a combination thereof, in which decongestant agents are dispersed or dissolved. Another hydrophobic vehicle comprises a pressure-sensitive adhesive matrix such as a dispersion of natural or synthetic rubber, an oleaginous plasticizer such as mineral oil, and a tackifying resin such as a terpene resin. Other adhesives can be used, such as vinyl emulsion adhesives, acrylic polymeric adhesives, vinyl acetate copolymers or silicone adhesives. Other medical adhesives which can be used will be apparent to those skilled in the art.

When the decongestant agents are mixed with the vehicle, an ointment is produced. The ointment is then stabilized by applying it to the greatly expanded surface area within the minute apertures and interstices between the fibrils, perforations and/or pores of the foraminous carrier. This, together with a thickening agent that can, if desired, be contained in the ointment, gives the ointment sufficient body, support and stability to hold it in place and prevent it from becoming smeared onto fingers, clothing, bed linens or onto other parts of the body where one or more of the decongestant agents could cause irritation, such as nasal mucosa or the eyes. In addition, the foraminous carrier supporting the decongestant enables all of the decongestant material to be easily and quickly removed when no longer needed with little or no residue left on the skin. In addition, by distributing the ointment over the extended surface of the foraminous carrier, more of the decongestant can be exposed to the air. The much greater exposed surface area facilitates evaporation of the decongestant, thus allowing more of the active agents it to be inhaled so as to improve the reduction of nasal or chest congestion and related cold and sinus symptoms.

Claim 1 of 41 Claims

1. A skin patch for the relief of the symptoms of cough, colds, nasal congestion or chest congestion, comprising,

symptomatic cold reliever supported upon a non-occlusive flexible foraminous carrier and means operatively associated with the carrier for securing the carrier to the skin surface to enable said symptomatic cold reliever to be available for natural inhalation during respiration through the mouth or nose;

wherein the skin patch is free of a 5-substituted furan methyl ketone.

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