A wound dressing of the type having a water soluble plasma soluble self-supporting flexible body and which may be aerated and foamed. The flexible body is self-adhering to the wound tissues and forms an artificial eschar with the moist elements at the situs of the wound. The flexible body is formed primarily from a water soluble dextran polymer

Catania, Patrick N.

King, James C.

English

Pacific McGeorge School of Law

Dressing and method for treating a wound

Scholarly Commons

University of the Pacific Scholarly Commons Pacific Patents Office of Research and Sponsored Programs (ORSP) 7-13-1976 Dressing and method for treating a wound Patrick N. Catania University of the Pacific, pcatania@pacific.edu James C. King University of the Pacific Follow this and additional works at: https://scholarlycommons.pacific.edu/patents  Part of the Medicine and Health Sciences Commons Recommended Citation Catania, Patrick N. and King, James C., "Dressing and method for treating a wound" (1976). Pacific Patents. 1. https://scholarlycommons.pacific.edu/patents/1 This Patent is brought to you for free and open access by the Office of Research and Sponsored Programs (ORSP) at Scholarly Commons. It has been accepted for inclusion in Pacific Patents by an authorized administrator of Scholarly Commons. For more information, please contact mgibney@pacific.edu. United States Patent (19) Catania et al. 11 3,969,498 (45) July 13, 1976 54 (75) 73 22 21 52 51 58 56) DRESSING AND METHOD FOR TREATING A WOUND Inventors: Patrick N. Catania; James C. King, both of Stockton, Calif. Assignee: University of the Pacific, Stockton, Calif. Filed: Sept. 13, 1973 Appl. No.: 397,203 U.S. C. .................................... 424/28; 424/45; 424/180; 424/DIG. 13 int. Cl’............................................ A61K 9/70 Field of Search................. 424/45, DIG. 13, 28, 424/180 References Cited UNITED STATES PATENTS 2,338,416 lf 1944 Fales............................ 424/DIG. 13 2,855,925 10/1958 Novak....... - - - - - - - - - 424/28 2,876,165 3/1959 Novak................................. 424/80 3,006,814 10/1961 Stanko................................ 424, 18O 3,122,479 2/1964 Smith................................., 4241 80 3,238,100 3/1966 Meyer et al........................... 424/28 3,328,259 6/1967 Anderson.............................. 424/28 3,577,516 12/1969 Gould et al........................... 424/45 FOREIGN PATENTS OR APPLICATIONS 814,001 5/1959 United Kingdom................... 424/45 832,799 4/1960 United Kingdom................. 424/80 Primary Examiner-Frederick E. Waddell Attorney, Agent, or Firm--Townsend and Townsend 57 ABSTRACT A wound dressing of the type having a water soluble plasma soluble self-supporting flexible body and which may be aerated and foamed. The flexible body is self adhering to the wound tissues and forms an artificial eschar with the moist elements at the situs of the wound. The flexible body is formed primarily from a water soluble dextran polymer. 6 Claims, No Drawings   3,969,498 DRESSING AND METHOD FOR TREATING A WOUND This invention relates to a dressing for a lesion or wound and a method for the use thereof in treating the same. More particularly it relates to dressings of the type having a water and plasma soluble flexible body that is capable of forming an artificial eschar with the exudates issuing from a lesion to which the dressing is applied. The dressing may contain medicaments or therapeutic agents for beneficially treating the wound. The dressing sequentially dissolves in the tissue of the wound, thereby sequentially releasing medicaments in the wound tissue. . . . . U.S. Pat. No. 3,328,259 to Anderson, patented June 27, 1967, describes dressings of the type provided by the present invention. The dressings in the Anderson patent are stated to be water and plasma soluble and when applied to a wound are capable of forming an artificial eschar to protect the same while gradually dissolving and releasing therapeutic agents. As de scribed in said patent such dressings have numerous advantages over previously used dressings. For exam ple, ordinary gauze type dressings become incorpo rated into the granulation tissue at the surface of the lesion so that the new healthy tissue may be pulled off when the dressing is removed. Ordinary dressings are undesirably bulky, have to be changed at frequent in tervals and cause an increase in maceration with subse quent prolongation of healing time. Occlusive dress ings, such as creams, lotions, ointments and the like, must be rubbed into the open lesion thereby producing pain. Also, removal of occlusive materials is difficult. Such materials are generally not satisfactory because they do not permit air contact with wounds and like ordinary dressings cause an increase in maceration of the healing tissue. s In contrast to ordinary gauze type dressings and oc clusive type dressings, the present flexible hydrophilic film is applied without inunction, is non-irritating to the lesion, is self-adhesive to the lesion, is easily removable by immersion for a few seconds in water or it may be left in place to be absorbed systemically, and excreted by the body. While being absorbed, therapeutic agents or medicaments may be gradually released to the wound. The present type of dressing is thus a highly efficient dosage form for local therapy. While the dressing provided by the Anderson patent, in common with the present dressing, provides many of these advantages over the older prior art, the principal component of the present dressing provides significant advantages over, the materials used in the Anderson patent. Specifically the Anderson dressing is formed from certain water and plasma soluble cellulose deriva tives. In the instant invention, the dressing is formed from water and plasma soluble dextran polymers in which the dextran is present in a sufficient amount to cause the flexible body formed therewith to form an artificial eschar with the moist elements at the situs of the wound. The dextran based flexible bodies of the present invention exhibit significant improvements in increased rates of solution in water and plasma in com parison with the flexible body dressings of the Ander son patent. For example, the Anderson dressings as disclosed in Example 4 of the Anderson patent require 1 minute and 10 seconds to dissolve in water. Dressings of the present invention are capable of dissolving in 30 seconds or less. 5 10 2 The dextran polymers of this invention are also ad vantageous in that they are generally available in a higher degree of purity than the cellulose materials of the prior art. Considering the application of the dress ing produced therewith and the fact that it dissolves into the wound to be carried systemically points up the significance of such a fact. Along the same lines, the present dextran polymers are fully compatible with the human body and present substantially no question of toxicity or other potential health hazards. The cellulose materials of the prior art are not known to be com pletely free from any such complications. Moreover, the present materials have utility with all patients. The 15 20 25 30 35 40 45 50 55 60 65 Anderson patent is not equally applicable to the extent that it suggests the use of sodium salts of cellulose deriv atives in the formation of its dressing. In certain in stances the systemic incorporation of the sodium cellu lose salts may introduce an undesirable excess of so dium in the body, taxing the body salt balance and inducing stress. In the broad aspects of the present invention, the general considerations described in the Anderson pa tent are applicable except of course for the use of the instant dextran polymers instead of cellulose deriva tives. In general the dextran polymer of the present invention will have an average molecular of about 40,000 to 100,000. For example, dressings made from specific dextran polymers having an average molecular weight of 40,000, 70,000 and 86,900 have been found to be satisfactory. Preferably before use the formulation is reduced in moisture content so that the water is about 5-15% by weight of the dressing and the dextran polymer is about 60-90% by weight of the dressing thereby providing a solid self-supporting film-like material of suitable thick ness. The dextran polymer is in an integral porous non discrete form. The preferred form of the present body is as an aerated foam. This provides oxygen to the wound and also is more rapidly soluble compared with a non-foamed embodiment. . Where an aerated foam is the desired form, it is bene ficial to include a surfactant in the formulation as a foaming agent. The surfactant also serves as an emulsi fier. Such surfactant may be anionic, cationic, nonionic or amphoteric and is selected for its compatability and stability, with the other components in the formulation. Examples of suitable surfactants are the ionic dioctyl sodium sulfosuccinate, the nonionic polyoxyethylene sorbitan monolaurate, and the amphoteric commercial material available under the name Miranol 2MCA Modified. As before the film or body of the present invention may include antiseptics, steroids, germicidals, anesthet ics, antibiotic materials and the like to minimize infec tion, pain and generally promote healing. Such materi als are herein referred to generally as medicaments. Specifically it is contemplated to include mafenide or povidone iodine into the present dressing body or film. In other embodiments silver salts such as silver nitrate, silver sulfadiazine, gentamicin and salts thereof and local anesthetics such as lidocaine, benzocaine and salts thereof are specifically contemplated. Such medi caments are advantageously applied to wounds through the present dressing as distinguished from the dosage forms previously used therefor. As before some residual moisture on the order of 5-15% by weight is desired so as to avoid a film that is either too brittle or too soft when outside of these lim 3,969,498 3 its. To this end plasticisers or humectants such as glyc erin, sorbitol, propylene glycol and the like may be included in the formulation. Optional ingredients may include anti-oxidants and stabilizers for examples. Also consistent with prior procedures, the present dressing may be sterilized as with ethylene oxide, CO, or the like. Packaging is preferably in air proof and moisture proof material. The following examples will illustrate the invention; EXAMPLE 1 As a typical solution for the preparing of hydrophilic aerated dry films of this invention, take 16 grams of dextran AMW 70,000 and dissolve it in 73.4 grams of water at 50-70°C. To this solution, add 10.4 grams of sorbitol solution and 0.2 grams of Miranol 2MCA Mod ified. After whipping the film forming solution for 10-15 minutes, the resultant foam may be spread to a uniform depth onto a Teflon coated drying surface and dried at 50-60°C to a moisture content of 5-15 per cent. Such a film is aerated and one square inch thereof dissolves in 0.1 ml. of water at room temperature in less than 30 seconds. *Average molecular weight EXAMPLE 2 Take 20 grams of dextran AMW 86,900 and together with 8 grams of polyoxyethylene sorbitan monolaurate, 16 grams of glycerin, and an amount of mafenide ace tate equivalent to 8.5 percent, by weight, of the dry film, and dissolve these in approximately 50 grams of water. After aerating the film forming solution by whip ping with a mixer, the resultant foam is cast, dried, and cut to appropriate size. EXAMPLE 3 Take 18 grams of dextran AMW 40,000, 10.4 grams of sorbitol solution, 1 gram of dioctyl sodium sulfosuc O 15 20 25 30 35 cinate, and dissolve these in approximately 70 grams of 0 water. In addition, silver salts, such as silver nitrate and silver sulfadiazine, may be added to the film forming solution to provide their therapeutic effects. EXAMPLE 4 Composition of film forming solution: Gms. Povidone Iodine 2.4 Preservative 0.2 Glycerin 0.5 Sorbitol Solution 2.0 Tween 20 1.0 dextran AMW 86,900 77.9 Composition of aerated dry foam after casting and drying: 45 50 55 60 65 4. Gns. Povidone fodine 2.4 Preservative 0.2 Glyccrin 0.5 Sorbitol Solution 2.0 Tween 20 2.0 dextran AMW 86,900 16.0 Water 2.4 EXAMPLE 5 G m S Lidocaine Hydrochloride dextran AMW 70,000 Propylene Glycol Alcohol Water 6 The above solution may be packaged in a pressurized aerosol utilizing suitable propellants. In this manner, the hydrophilic foam may be generated immediately prior to use by actuating the aerosol. EXAMPLE 6 Gms. Dextran AMW 86,900 20.0 Sorbitol Solution 2.6 Water 77.4 The above film forming solution comprises a formula tion to be used in preparing a non-aerated film for use as skin grafting material. What is claimed is: 1. In a wound dressing of the type having a water soluble solid, self-supporting flexible body consisting essentially of a film-forming polymer in integral non discrete form in an amount sufficient to form an artifi cial eschar with the moist elements at the situs of the wound, the improvement in which said film-forming polymer is a plasma and water soluble dextran polymer having an average molecular weight of about 40,000 to about 100,000. 2. The improvement in accordance with claim 1 wherein said dextran body is porous. 3. The improvement in accordance with claim 1 wherein said dextran polymer is about 60-90% by weight of said flexible body. 4. The improvement in accordance with claim 1 wherein said flexible body contains about 5-15% by weight of water. 5. The improvement in accordance with claim 1, wherein said flexible body contains medicaments pre selected to treat the wound to be covered by said flexi ble body. 6. The improvement in accordance with claim 1 wherein said flexible body is in the form of an aerated foam. sk k k k ck 

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Dressing and method for treating a wound

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