Patent Application
20080063694
One way of providing molecular iodine (12) on site with a patient, rather than having to find a way of transporting it to a site) is to provide reactants that can readily produce molecular iodine on-site in a controllable reaction. One format of providing the molecular iodine would be through the oxidation-reduction reaction between two salts or compounds to produce the molecular iodine. It is a readily controlled environment where the reaction can be performed in an aqueous environment. One reaction that can effect this would be generically described as:
X+Y−+Z+I−→X∘+Z+Y−+I2
In this reaction scheme, X is a metal (preferably a multivalent metal and more particularly a divalent metal), Y is an anion (preferably a multivalent anion and more preferably a divalent anion, and an anion having at least two oxygen atoms), Z is an alkali metal or alkaline cation. Examples of X are copper, iron, manganese, lead, nickel, tin, and the like, Y can be sulfate, sulfite, sulfonate, carbonate, phosphate, phosphate, nitrate, nitrie, borate, and the like, and Z can be sodium, lithium, potassium, ammonium, magnesium, aluminum, and the like. One preferred reaction would be:
Cu+2 SO4−2+K+I−→Cu∘+K2SO4+I2
This reaction takes place readily in an aqueous environment and produces molecular iodine at a controlled rate. The reaction may be used by wetting, dispersing or dissolving the molecular iodide and allowing the iodine in the carrying material be released and carried to the site 9which may be the carrying material itself, such as the fabric, clay, fibers, film etc.) penetrate the area intended to be treated. The iodine may persist for sufficient time to treat the area, particularly within a wetted material on the surface of a patient. The reaction may also be used by dispersing or mixing the two ingredients into the carrying material (e.g., the fabric, fiber, film, sheet, etc.), either with additional water provided, with water of hydration on the first reactant (e.g., X+Y−·nH20, such as CuSO4·5H20) or with ambient water in the carrying material. The two reactants may be physically separated from each other before being combined for application or reaction, as in separate capsules, fibers, layers or the like. The two reactants may be provided as a solid carrier medium that separates the two reactants until they are in contact with water (as in a soluble carrier such as polyvinyl alcohol, gelatin, amylase, sugars and the like, in pellet, fiber, dust, particle or block form). The two reactants may be independently coated with a soluble/dispersible coating and the two ingredients kept in a single water-penetrable layer.
Although the materials of the described technology may be provided in a vast array of materials and compositions applied to the surface of patients, such as bandages, bandaids, diapers, gauze, wraps, sanitary napkins, tampons, plugs, sheet coverings 9 e.g., on beds) and the like, the discussion will emphasize diapers and incontinence diapers for simplifying the disclosure, without intending to limit the scope of the invention.
The Technology described herein is performed by applying a solid carrier system to a patient, and awaiting the presence of sufficient water on or in the carrier system to activate the ingredients and cause the gaseous iodine to form in sufficient concentration in the solid carrier to attenuate, reduce or eliminate bacterial growth in the solid carrier. A simple format, in considering diaper-like materials for any age animal, would include at least the following formats:
The process may use the above reaction to form the molecular iodine represented by
XY+ZI→X∘ZY+I2
wherein X is a metal, Y is an anion, Z is an alkali metal or alkaline cation, or where X is a multivalent metal, Y is a multivalent anion, and Z is an alkali metal or alkaline cation, and is preferably represented by
Cu+2SO4−2+K+I−→Cu∘+K2SO4+I2.
The process may be performed where the two reactants are carried in a superabsorbent polymer. The solids carriers for the two reactants may also include compositions of the present that comprise superabsorbent or non-superabsorbent polymers, natural products (e.g., papers, cellulosic solids, water-insoluble porous materials which absorb or adsorb the film-forming material within the structure, water-soluble porous materials which absorb or adsorb the film-forming material within the structure, porous containers which merely slowly release a volume of the film-forming material, porous containers which both dissolve and physically release volumes of the film-forming composition through pores, and the like. In general, selection of an effective application rate can depend on habitat depth, surface debris, emergent and surface vegetation, organic matter, microbial and algal concentration, the specific target species, and the developmental stage of the target species. Superabsorbent polymers are described, by way of non-limiting examples in U.S. Pat. Nos. 6,403,674; 4,731,391. Superabsorbent polymers, including starch graft co-polymers, are known in the art. See, for example, those described in U.S. Pat. Nos. 4,375,535 and 4,497,930 (incorporated herein by reference), which have disclosed uses as adhesives, flocculants, sizes, water-retaining materials for agriculture and water-absorbing materials for sanitary materials. However, the spectrum of advantages attendant the use of superabsorbent polymers in solid and flowable terrestrial insecticidal, pesticidal or insecticidal/pesticidal delivery compositions have gone unrecognized.
The superabsorbent polymers of the present invention are synthetic organic polymers which are solid and hydrophilic, absorbing over 100 times their weight in water. These superabsorbent polymers are typically in a powder, granule, extruded, or flake form, adapted to be blended and/or agglomerated into any shape or form.
The superabsorbent polymers may be, for example, acrylamide alkali metal acrylate co-polymers; propenenitrile homo-polymers, hydrolyzed, alkali metal salts; polymers of propenamide and propenoic acid, alkali metal salts; hydrolyzed acrylonitrile co-polymers, and starch graft co-polymers and ter-polymers thereof. All of these are designed to be hydrophilic, absorbing over 100 times their weight in water. The resulting hydrophilic polymers can absorb from over one hundred to greater than about 5000, more typically around 500 to about 1,000, times their own weight in water (measured using distilled water, pH 7.5, 25, 760 mm Hg. absorption within about 30 seconds). However, the absorption or swelling capacity and absorption or swelling time typically varies with each specific superabsorbent polymer.
One class of superabsorbent polymers include combinations of a starch and organic monomers, oligomers, polymers, co-polymers or ter-polymers. They may be manufactured in a variety of ways, for example, the methods described in U.S. Pat. Nos. 4,375,535 and 4,497,930, and can be, for example, the product of grafting corn starch (amylopectin) with acrylonitrile (an acrylic monomer or oligomer). A second class of superabsorbent polymers includes combinations of acrylamide and acrylate polymers, co-polymers and ter-polymers.
The following examples are provided as prophetic descriptions of formats for delivery of technology according to the descriptions of the present invention.
Fibers would extruded in a non-aqueous solvent of polyvinyl alcohol in two separate batches in combination with particulate reactants. One set of fibers would comprise 40% by weight of Copper Sulfate and the other set of fibers would comprise 40% by weight of Potassium Iodide. The two separate fibers would blended as 5% by total weight of fabric material into the fiber filled used in a diaper. The relatively low concentration (5%) of total added fiber would be expected to minimally change the properties expected from the fiber fill, except for the additional antimicrobial function, Upon accidental release of urine (an aqueous solution) into the diaper, the polyvinyl alcohol would dissolve, the two reactants would dissolve in a single solution, the reactants would react, and the gaseous iodine would be produced.
The technology described herein may be generally described as an article for application to the body of an animal (including humans) to provide both absorbency and antimicrobial activity. The article may comprise a water absorbent material; and a composition that reacts with water to produce molecular iodine. The composition provides a local concentration (in the water) of at least 10 parts per million iodine in water carried by the material (that is actual water supported by the water absorbent material) when the material has 5% by weight of water present in the water absorbent. The 5% is with respect to the total weight of water to the water absorbent material. The article may be a diaper, sanitary pad, bandage, bandaid or wrap for an animal. The water absorbing material preferably comprises water absorbing fibers. The composition that reacts with water to form molecular iodine may comprise at least two salts, one of which at least two salts comprises an iodide salt. The at least two salts may be selected from the groups consisting of a) XY and b) Z I, wherein X is a metal, Y is an anion, and Z is an alkali metal, ammonium or alkaline cation. X is preferably a divalent metal cation. Y is preferably selected from carbonate, sulfate, sulfite, phosphate, phosphate, nitrate and nitrite, and Z is preferably selected from the group consisting of lithium, potassium, calcium, magnesium, sodium and ammonium. The composition that reacts with water to form molecular iodine preferably comprises cupric sulfate and potassium iodide.
The article may have the iodine forming composition appropriately located within the article. For example, where the article is a diaper, it may have more than 70% of total composition in a central 50% of volume of the diaper. There is little need for antimicrobial activity on the portions of the diaper contacting the outer portions of the hips. Similarly, there would be little need for such activity along the waistband of the diaper. It is therefore desirable to concentrate the active materials in the diaper where the water (e.g., urine) is likely to be emitted. The iodine would migrate through the path of the water to all wetted areas.
A method of inhibiting microbial growth in an article provides a composition within the article, the composition comprising at lest two compounds that react in the presence of water to produce molecular iodine, and placing the article against the skin of an animal where an aqueous emission from the animal may occur. The method acts so that upon addition of water in an amount of between 10 and 100% by weight of the composition, a concentration of at least 10 parts per million of iodine is produced in the water in les than 15 minutes.
Another improvement would be to include starch materials into the diaper or the surface of the diaper so that the released iodine would cause the standard reaction for starch testing and a blue coloration would appear on the surface of the diaper to alert caregivers that urination had occurred.
Two porous films of water-soluble or water-dispersible material such as mannitol are extruded, the porosity provided by mechanical punching of the film of leaching of materials from the film, as well understood in the art. The separate films would contain 40% by weight of Copper Sulfate and 40% by weight of Potassium Iodide. The films can be used as adjacent or opposite side containers for the fiber fill (preferably with a separate non-dissolvable film).
Individual granules of Copper Sulfate and Potassium Iodide are coated with water-soluble/dispersible coatings, preferably in the 2-8 micron thickness range. The uncoated particles would preferably have a diameter of between 5-50 microns so that they could be carried in fiber fill for a diaper without too ready settling out of the fiber fill. The coated particles are mixed into the fiber fill, either alone or with a tacky material (on the fiber or on the particles, such as a partially dried coating on the particles) to avoid separation. The fiber particle blend would constitute the fiber fill in a diaper.
The concentration of the iodine forming material may be selected in the article according the ultimate needs and designs of the manufacturer, and the level of ant-bacterial effect desired. The concentration of the iodine gas in the liquid in the absorbent material is one measure of the desired results, and a further measure of the desired results is referred to in the art as the kill percentage, a measure of the percent of a specific bacteria (e.g., E. coli) in a liquid sample that would be killed in 5 minutes by the level of active ingredient present. An example would be that the presence of about 8 parts per million of gaseous iodine dissolved in the aqueous material in the absorbent material would have a kill percentage over 50%. It would be desired, as noted above, to have higher concentrations of gaseous iodine in the liquid so that kill percentages are at least 60%, at least 70%, at least 80% and even at least higher than 90% for targeted bacteria and other microbes. Depending upon the specific bacteria or microbe selected for the measurement, the liquid may have to be provided with at least 10 parts per million (ppm), at least 15 ppm, at least 20 ppm, or at least 25 ppm by controlling the amount of reagents added, the rate of reaction of the reagents, and other controls aimed at keeping the iodine in solution in the liquid, such as providing thickening agents or other materials that would reduce the volatility of the iodine gas from the solution.
All references cited herein are incorporated by reference in their entirety.
