WO2002026178A1

WO2002026178A1 - Treatment of swine's anemia and low weight

Info

Publication number: WO2002026178A1
Application number: PCT/US2001/042313
Authority: WO
Inventors: Stephen E. Bachman; Michael E. Hubbert
Original assignee: Ganado Research, L.L.C.
Priority date: 2000-09-26
Filing date: 2001-09-26
Publication date: 2002-04-04
Also published as: AU2002211817A1

Abstract

A plurality of iron-containing formulations transdermally administrered to juvenile swine to treat juvenile swine anemia are disclosed. Applicants' transdermal formulations optionally include other elements, including copper, zinc, and selenium. In addition, Applicants' transdermal formulations also optionally include Vitamin C, Vitamin E, skin penetration enhancers, solvents, lecithin, and/or a Coleus Forskholi extract. A method to treat juvenile swine anemia using one or more of Applicants' transdermal forumulations. A method to increase the weight gain of juvenile swine using one or more of Applicants' transdermal formulations.

Description

TREATMENT OF SWINE'S ANEMIA AND LOW WEIGHT

Field Of The Invention

Applicants' invention relates to a composition and method to treat anemia and/or to increase weight in juvenile swine. Applicants' composition comprises one or more therapeutic agents including an iron-containing material in optional combination with a copper-containing material, a zinc-containing material, Vitamin E, Vitamin C, one or more amino acids, and/or selenium.

Background Of The Invention In general, iron-deficient anemia, termed hypochromic-microcytic anemia, is generally associated with young, rapidly growing animals deprived of iron in their diet or from their environment. Iron was not recognized as a vital nutrient for animals until the late 1800s. Research into bioavailability of iron-containing foodstuffs was limited because anemia is of little significance in farm species other than swine. Under one embodiment, Applicant's invention is directed to treating iron deficiency anemia in juvenile swine. The link between anemia in nursing pigs and iron deficiency was not made until 1924.

The newborn pig contains approximately 40 milligrams of iron at birth, mostly in the form of hemoglobin. The neonatal pig has been determined to have a requirement of 7 to 16 milligrams of iron per day for normal growth. Maximum hemoglobin levels were produced in neonate pigs at 14 days of age when injected with either 100 or 150 milligrams of iron dextran within three days after birth. Maximum growth rate of pigs weaned at three weeks of age was acquired through supplementation of 100 milligrams in the form of injectable iron dextran. Iron deficiency anemia can develop very rapidly in nursing piglets reared in confinement because of (1) low body storage of iron in the newborn pig, (2) low iron content of sow's colostrum and milk, (3) elimination of contact with iron from soil, and (4) the rapid growth of the nursing piglet. Regarding the first factor, low body storage of iron in the newborn pig: The baby pig is born with a total of about 40 milligrams of iron in its body, most of which is present in the form of hemoglobin in blood and storage forms in the liver. With an iron requirement of about 7 milligrams daily to maintain blood hemoglobin level in the normally growing baby pig, it is apparent that without supplemental iron, body stores are insufficient for survival. Attempts to increase body iron stores in the fetal pig by administering large amounts of iron to the sow in late gestation, either in her feed or by injection, have not been successful.

With respect to the second factor, low iron content of sow's colostrum and milk: Sow's colostrum and milk is a good source of all nutrients the baby is known to require, with the exception of iron. The concentration of iron in colostrum is seldom greater than 2 parts per million (ppm), and in milk is lower, averaging about 1 ppm. Because of the low concentration of iron in sow's milk, the baby pig cannot obtain more than about 1 milligrams of iron daily from this source. This level falls far short of its requirement of 7 milligrams daily.

Attempts to increase significantly the iron concentration in sow's milk by feeding high levels of iron in the sow's late gestation and lactation diet, or by injecting the sow with a large amount of iron-dextran late in gestation or during lactation have not been successful. With respect to the third factor, elimination of contact with iron from soil: The baby pig is equipped with a snout with which it is able to root almost as soon as it is born. Thus, under natural conditions the piglet could obtain its iron from the soil. When the piglet is placed on concrete or reared in confinement in a central farrowing facility, it is denied this opportunity. With respect to the fourth factor, rapid growth of the nursing piglet: Compared to other domestic mammals, the baby piglet has a tremendous ability to grow. The baby piglet is capable of increasing its birth weight 1000% during the first 6 weeks of life. This rapid growth of the nursing pig with the resulting increase in plasma volume demands a high intake of iron to maintain adequate hemoglobin. There is no difference in gender (sex) of the piglet in developing iron deficiency anemia.

There are many sources of iron that can be used to prevent anemia. Iron-dextran injected in the muscle is an effective method. Injections in the neck or forearm are preferred to injecting in the ham. Common levels are 150-200 milligrams of iron as iron- dextran, usually given the first 2 to 3 days. Overdoses of iron should not be given, however, because such overdoses may induce shock.

Iron also can be mixed in the feed or in the drinking water. Supplying uncontaminated soil in the pig area is another method of supplying iron but is not used much in today's confinement systems.

In 3- to 10- day-old pigs, the toxic oral dose of iron from ferrous sulfate is approximately 600 milligram/kg of body weight. Clinical signs of toxicity are observed within 1 to 3 hours after iron is fed. Injectable iron (100 milligrams as iron dextran) has been found to be toxic to pigs from vitamin-E-deficient dams. A dietary level of 5000 ppm of iron produces rachitic lesions, which may be prevented by increasing the level of dietary phosphorus. (SOURCE: 1998 NRC Nutrient Requirements of Swine, p. 55.)

In addition to iron, young swine may also require supplemental copper. U.S. Pat. No. 5,824,707 teaches that iron in swine is not fully utilized without available copper. Copper is an essential element involved in growth and maintenance of tissues and immunity. "Copper deficiency is known to cause anemia, diarrhea, bone disorders, neonatal ataxia, changes in hair and wool pigmentation, infertility, cardiovascular disorders, impaired glucose and lipid metabolism and a depressed immune system." Davis, G.K. and W. Mertz, Trace Elements in Human and Animal Nutrition, pp 301-364, Academic Press, Inc., San Diego, CA.(1987).

Copper is a key component of many enzyme systems which when impaired can directly or indirectly cause many of the symptoms of copper deficiency. For example, Orr et al. (1990) showed that blood copper levels decreased and urinary copper excretion increased as morbidity increased in calves infected with the infectious bovine rhinotracheitis (IBR) virus. Orr, C.L., D.P. Hutcheson, R.B. Grainger, J.M. Cummins and R.E. Mock, Serum Copper, Zinc, Calcium and Phosphorus Concentrations of Calves Stressed By Bovine Respiratory Disease and Infectious Bovine Rhinotracheitis, J. Anim. Sci. 68:2893 (1990). With chronic disease, liver copper stores may become depleted resulting in increased susceptibility to secondary infections.

It is known that the immune function in copper deficient cattle can be impaired even though there was no evidence of anemia or depression in growth. Cattle that were marginally deficient in copper had reduced superoxide dismutase activity and decreased neutrophil bactericidal capability. These animals were less efficient at killing Staphylococcus aureus, an organism which often causes mastitis in cattle. This could explain the observation that dairy herds which are marginal in their copper status often seem to have a higher incidence of mastitis. Effective Copper Nutrition for Farm Animals by Larry L. Berger, Ph.D., Professor, Animal Sciences, University of Illinois.

Animals without the ability to ingest adequate levels of copper will likely become susceptible to antigenic invasion and suffer from compromised health. Copper applied transdermally could aid in the prevention of these maladies.

Zinc has been recognized as an essential trace mineral for plants, animals and humans since the 1930s. Zinc functions in over 200 enzymatic reactions in the body. Zinc plays a key role in the synthesis and stabilization of genetic material. Zinc is necessary for cell division and the synthesis and degradation of carbohydrates, lipids and proteins, and is therefore essential for the growth and repair of tissue.

As part of the enzyme copper-zinc superoxide dismutase, zinc helps to protect cells and other compounds against the effects of free radicals. Zinc is vital for the normal structure and function of cell membranes. It is vital for the formation of connective tissue, teeth, bone, nails, hair and skin. Zinc may play a role in calcium uptake in bone and modulate the effects of growth hormones.

Zinc is considered one of the most important nutrients for the immune system as it is necessary for healthy antibody, white blood cell, thymus gland and hormone function. It is therefore vital in maintaining resistance to infection and in wound-healing. Zinc is necessary for the secretion, synthesis and utilization of insulin. It also protects the insulin-producing pancreatic beta cells against destruction.

Zinc is also involved in the metabolism of the pituitary, thyroid and adrenal glands, the ovaries and the testes. It is vital for healthy male sex hormone and prostate function. Normal skin function requires zinc. It is involved in oil gland function, local hormone activation, vitamin A binding protein formation, wound-healing, inflammation control and tissue regeneration. Zinc applied transdermally could aid in the prevention of these maladies.

Vitamin E is recognized as an essential nutrient for all species of animals, including humans. Balance studies indicate that vitamin E is poorly absorbed or at least retained in the body. Much of the natural occurring form of vitamin E (α-tocopherol) is subject to destruction in the digestive tract. Very little (2%) of the feed vitamin E is passed to the young through milk.

Vitamin E has a number of different but related functions. One of the most important is its role in intercellular and intracellular antioxidant. If lipid hydroperoxides are allowed to form in the absence of adequate tocopherols, direct cellular damage can occur, in which peroxidation of lipids destroys structural integrity of the cell and causes metabolic derangements.

Currently, considerable attention is being focused on the role of vitamin E and selenium play in protecting leukocytes and macrophages during phagocytosis, the mechanism whereby mammals immunologically kill invading bacteria. Large doses of vitamin E protected chicks against E. coli. Pigs and calves have also demonstrated increased immune response with supplemental vitamin E.

In ruminants a deficiency of vitamin E and selenium is associated with white muscle disease. In mild cases, selenium deficiency can show dramatic improvement with vitamin E injections. Swine are also susceptible to muscular dystrophy when both selenium and vitamin E are deficient.

After period of stress, illness or extended periods of grazing on dry forages animals are supplemented with vitamin E. This can occur in the feed or by injections. However, many animals that are sick do not consume feed and thereby do not receive supplementation through the feed.

With respect to livestock animals, transdermal administration of iron, copper, zinc, Vitamin C, and/or Vitamin E has distinct advantages over feeding the desired ingredients as the animal is not required to consume a predetermined amount of feed to achieve the desired supplementation level. When animals are sick they tend not to eat, and this is a prime time when the animal's nutrient requirements are elevated or supplementation of a pharmaceutical is needed. Furthermore, feeding high levels of specific nutrients can interfere with absorption of other nutrients. The non-invasive nature of transdermal application may not require the animal be captured and restrained to administer a supplement. A transdermal carrier can deliver a predetermined amount of product with minimal disturbance to the animal.

With respect to livestock animals, transdermal administration has distinct advantages over injections as injections require restraint of an animal, the stress of which increases cortisol secretion which in turn reduces immune response and increases protein catabolism. Injection also may leave a site or lesion where the needle penetrated the tissue, these unsightly defects must be removed prior to meat sales. Furthermore, there is less chance of infection from the injection site and less pain to the animal.

Summary Of The Invention Applicants' invention includes a plurality of iron-containing formulations that can be transdermally administered to juvenile swine to treat juvenile swine anemia. By transdermal administration, Applicants mean application of one or more medicaments onto, and passage of such medicament(s) through, an intact body surface, i.e. any route of administration that does not involve use of a needle or administration via feeding. Such transdermal administration includes passage of one or more medicaments through an intact portion of an animal's skin, mucosa, rectum, vagina, external ear, and/or nasal pharnyx. Applicants' transdermal formulations optionally include other elements, including copper, zinc, and selenium. In addition, Applicants' transdermal formulations also optionally include Vitamin C, Vitamin E, skin penetration enhancers, solvents, lecithin, and/or a Coleus Forskholi extract.

Applicants' invention further includes a method to treat juvenile swine anemia using one or more of Applicants' transdermal formulations. Applicants' invention further includes a method to increase the weight gain of juvenile swine using one or more of Applicants' transdermal formulations.

Brief Description of the Drawings The invention will be better understood from a reading of the following detailed description taken in conjunction with the drawings in which like reference designators are used to designate like elements, and in which:

FIG. 1 graphically depicts weight versus time data for juvenile swine treated with two of Applicants' transdermal formulations and with two control formulations;

FIG. 2 graphically depicts the percent overall weight gain observed in juvenile swine treated with two of Applicants' transdermal formulations and with two control formulations;

FIG. 3 graphically depicts the percent daily weight gain observed in juvenile swine treated with two of Applicants' transdermal formulations and with two control formulations;

FIG. 4A recites certain of Applicants' iron-containing transdermal formulations; FIG. 4B recites certain of Applicants' iron-containing transdermal formulations;

FIG. 4C recites certain of Applicants' iron-containing transdermal formulations; FIG. 5 A recites certain of Applicants' iron / copper-containing transdermal formulations;

FIG. 5B recites certain of Applicants' iron / copper-containing transdermal formulations;

FIG. 5C recites certain of Applicants' iron / copper-containing transdermal formulations; and

FIG. 6 summarizes certain of Applicants' iron / copper / zinc-containing transdermal formulations. Detailed Description Of Preferred Embodiments

It is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific compositional and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. All ingredients of Applicants' transdermal formulations are non-toxic and safe for animal use, including human use. By transdermal administration, Applicants mean application of one or more medicaments onto, and passage of such medicament(s) through, an intact body surface, i.e. any route of administration that does not involve use of a needle or administration via feeding. Such transdermal administration includes passage of one or more medicaments through an intact portion of an animal's skin, mucosa, rectum, vagina, external ear, and/or nasal pharnyx.

All ingredients of Applicants' formulations are non-toxic and safe for animal use, including human use. In a first embodiment, Applicants' formulation includes elemental iron. This elemental iron may be present in the 0 valence state, the +2 oxidation state, or the +3 oxidation state. Iron in the +2 oxidation state is preferred. Counter ions for the ferrous ions include halides, oxides, hydroxides, sulfate, carbonate, citrate, succinate, lactate, glycine sulfate, gluconate saccharate, complexes with dextrans and/or glutans, or complexes with certain amino acids.

In certain embodiments of Applicants' method, up to about 300 milligrams of iron is transdermally administered up to about 30 days after birth to one or more juvenile swine in need thereof. In other embodiments of Applicants' method, between about 50 milligrams and about 300 milligrams of iron is transdermally administered up to about 30 days after birth to one or more juvenile swine in need thereof. By juvenile swine, Applicants mean new-born piglets up to the age of about one month.

Certain embodiments of Applicants' composition include ferrous or ferric ions in combination with dextrans, gluconate, glycine, saccharate, and mixtures thereof. In order to minimize the likelihood of iron toxicity, however, Applicants have found it preferable that the elemental iron should be slowly released into the blood system. Applicants' have found that use of iron in combination with gluconic acid, glycine, and mixtures thereof, facilitates both rapid transdermal delivery along with slow release into the blood system of animals. Iron dextran is available commercially, and generally contains about 150 milligrams elemental iron per milliliter of solution. Iron dextran was originally formulated for injection deep into muscle, usually in the buttock. Dextran is a water soluble polysaccharide obtained from the hydrolysis of starch. Certain embodiments of Applicants' invention include iron in combination with one or more of the following Dextrans:

Dextran 75, Pyrogen Free, M.W. 60,000-90,000;

Dextran 40, Pyrogen Free, M.W. 32,000-48,000;

Industrial P, M.W. 39,000-49,000;

Industrial R, M.W. 60,000-90,000; Industrial HH, M.W. 200,000-300,000;

Industrial H, M.W. 100,000-200,000;

Native 2P, M.W. 5,000,000-40,000,000;

Industrial L, M.W. 15,000-22,000;

Industrial XL, M.W. 8,000-12,000; and Industrial XXL, M.W. 3,000-7,000.

U.S. Pat. No. 4,067,994 teaches preparation of a iron/methionine complexes, and is hereby incorporated herein by reference. Specifically, Example 2 of the '994 patent teaches preparation of a 1:1 ferrous methionine acid sulfate, and Example 4 teaches preparation of a ferric/ferrous methionine complex. In one embodiment, Applicants' composition contains an iron complex selected from the group consisting of iron dextran, iron sodium gluconate, iron saccharate, or ferrous methionine, ferric/ferrous methionine, and mixtures thereof.

In another embodiment, Applicants have found that inclusion of certain amino acids facilitates the transdermal delivery of iron. In this embodiment, free amino acids are added to the iron complex described above. These amino acids include histidine, lysine, cysteine, and mixtures thereof. It is thought these amino acids form tridentate chelates with iron thereby facilitating the transdermal delivery of the iron. In certain embodiments of Applicants' transdermal composition, these amino acids are present in an amount between about 5 weight percent and about 50 weight percent. FIGs. 4A, 4B, and 4C summarize the weight percentages of Applicants' iron- containing transdermal formulations. The formulations recited in FIGs. 4A, 4B, and 4C do not recite weight percentages for solvents / carriers used. As those skilled in the art will appreciate, formulations A through AV can be applied in solution using one or more solvents discussed below. In alternative embodiments, formulations A through AV can be applied using an emulsion rather than a solution. In certain embodiments, formulations A through AV are dissolved in one or more solvents, and are present in those solutions in an amount between about 5 weight percent and about 50 weight percent. In alternative embodiments, formulations A through AV are mixed in a water- in-oil emulsion, and are present in those emulsions in an amount between about 5 weight percent and about 50 weight percent. In still other embodiments, formulations A through AV are mixed in an oil-in-water emulsion, and are present in those emulsions in an amount between about 5 weight percent and about 50 weight percent.

In another embodiment, Applicants' transdermal composition includes elemental copper, with or without elemental iron. The elemental copper may be in the 0 valence state, or may be in the +2 or +3 oxidation state. Copper ions in the +2 oxidation state are preferred. Counterions may include halides, carbonates, oxides, hydroxides, sulfates, citrates, complexes with dextrans or glutans, complexes between copper and certain - amino acids having terminal amino groups, and mixtures thereof.

U.S. Pat. No. 4,948,594 teaches preparation of copper complexes having structure I, wherein n is between 1 and 5, and Z is an anion and y is the number required to electrostatically balance the set.

As those skilled in the art will appreciate, Compound I where n = 5 is a complex between the amino acid lysine and copper. Lysine is an essential amino acid in the diet of mammals. Lysine, however, cannot be synthesized by mammals, such as piglets, at a rate adequate to meet the animal's metabolic requirements. Therefore, supplemental lysine must be supplied. In prior art systems, lysine was supplied in the animal's diet. In this embodiment of Applicants' invention, lysine is supplied in a copper/lysine complex.

In certain embodiments, elemental copper is transdermally administered anytime for up to about 30 days to one or more juvenile swine in need thereof present in an amount up to about 500 milligrams. In other embodiments, elemental copper is transdermally administered anytime for up to about 30 days to one or more juvenile swine in need thereof in an amount between about 50 milligrams and about 400 milligrams. In other embodiments, elemental copper is transdermally administered anytime for up to about 30 days to one or more juvenile swine in need thereof in an amount between about 150 milligrams and about 200 milligrams .

FIGs. 5A, 5B, and 5C summarize the weight percentages of Applicants' iron and copper containing transdermal formulations. The formulations recited in FIGs. 5A, 5B, and 5C do not recite weight percentages for solvents / carriers used. As those skilled in the art will appreciate, formulations BA through CZ can be applied in solution using one or more solvents discussed below. In alternative embodiments, formulations BA through CZ can be applied using an emulsion rather than a solution. In certain embodiments, formulations BA through CZ are dissolved in one or more solvents, and are present in those solutions in an amount between about 5 weight percent and about 50 weight percent. In alternative embodiments, formulations BA through CZ are mixed in a water-in-oil emulsion, and are present in those emulsions in an amount between about 5 weight percent and about 50 weight percent. In still other embodiments, formulations BA through CZ are mixed in an oil-in-water emulsion, and are present in those emulsions in an amount between about 5 weight percent and about 50 weight percent.

In another embodiment, Applicants^'' formulation includes elemental zinc, with or without iron and with or without copper. The elemental zinc may be in 0 oxidation state or in the +2 oxidation state. Counterions may include halides, carbonates, oxides, hydroxides, sulfates, citrates, complexes with dextrans or glutans, complexes with amino acids, and mixtures thereof.

Equimolar complexes between zinc and lysine and/or methionine are preferred. Preparation Method 5 recited in U.S. Pat. No. 5,061,815 teaches preparation of a 1:1 zinc/lysine complex. This '815 patent is hereby incorporated herein by reference. U.S. Pat. No. 5,278,329, incorporated by reference herein, teaches preparation of a 1:1 complex between zinc and methionine.

FIG. 6 summarizes the weight percentages of certain of Applicants' iron, copper, and zinc containing transdermal formulations. Other iron, copper, and zinc containing transdermal formulations not recited in FIG. 6 also optionally include one or more of histidine, lysine, cysteine, selenium, Vitamin E, skin penetration enhancers, Coleus Forskholi extract, and/or lecithin. These optional ingredients are present in about the weight percentages recited in FIGs. 4A, 4B, 4C, and 4D. In addition, the formulations recited in FIG. 6 do not recite weight percentages for solvents / carriers used. As those skilled in the art will appreciate, formulations DA through DS can be applied in solution using one or more solvents discussed below. In alternative embodiments, formulations DA through DS can be applied using an emulsion rather than a solution. In certain embodiments, formulations DA through DS are dissolved in one or more solvents, and are present in those solutions in an amount between about 5 weight percent and about 50 weight percent. In alternative embodiments, formulations DA through DS are mixed in a water-in-oil emulsion, and are present in those emulsions in an amount between about 5 weight percent and about 50 weight percent. In still other embodiments, formulations DA through DS are mixed in an oil-in-water emulsion, and are present in those emulsions in an amount between about 5 weight percent and about 50 weight percent.

In certain embodiments, elemental zinc is transdermally administered any time for up to about 30 days to one or more juvenile swine in need thereof in an amount up to about 2,000 milligrams per head. In other embodiments, elemental zinc is transdermally administered any time for up to about 30 days to one or more juvenile swine in need thereof in an amount between about 50 and about 400 milligrams per head. In alternative embodiments, elemental zinc is transdermally administered any time for up to about 30 days to one or more juvenile swine in need thereof present in an amount between about 150 and about 200 milligrams per head. In a separate embodiment, Applicants' composition includes Vitamin E, with or without iron, with or without copper, and with or without zinc. In certain embodiments, Vitamin E is transdermally administered for up to about 30 days to one or more juvenile swine in need thereof present in an amount up to about 5000 International Units ("IU") per head. Selenium may optionally be added to the formulation along with Vitamin E. In certain embodiments, selenium is transdermally administered any time for up to about 30 days to one or more juvenile swine in need thereof in an amount up to about 5 milligrams per head.

In a separate embodiment, Applicants' composition includes Vitamin C, with or without iron, with or without copper, and with or without zinc. In certain embodiments, Vitamin C is transdermally administered daily for up to about 30 days to one or more juvenile swine in need thereof in an amount up to about lg per day. In alternative embodiments, Vitamin C is transdermally administered daily for up to about 30 days to one or more juvenile swine in an amount up to about 250 milligrams.

Lecithin is a complex, naturally-occurring mixture of phospholipids that most often comes from soybean oil. Phospholipids are a part of almost all biological membranes. Phospholipids are the surface-active portion of lecithin, the part that gives lecithin most of its functional properties.

In another embodiment, Applicants' formulation includes lecithin. Applicants have found that the phospholipids in lecithin function as emulsifiers providing a variety of surface-active properties to two different substances like oil and water, allowing them to blend together easily. In this embodiment, lecithin is present in Applicant's composition in an amount between about 0.01 weight percent and about 10 weight percent. Applicants' compositions can be effectively administered via transdermal delivery without including a substance capable of in vivo stimulation of adenosine 3', 5 '-cyclic monophosphate, and without including a substance capable of in vivo stimulation of guanosine 3', 5'-cyclic monophosphate. In a separate embodiment of Applicants' invention, substances such as an extract of Coleus Forskholi, may optionally be included in Applicants' formulation at a level of between about 0.0001 weight percent to about 1.0 weight percent.

Applicants' composition is preferably dissolved in a solvent system. The solvent system may include water along with lower alcohols such as ethanol, isopropyl alcohol, propyl alcohol, and the like. Preferably, such alcohols have carbon contents between 2 and about 6. The solvent system may additionally include glycols such as ethylene glycol, propylene glycol, glycerol, and the like. The solvent system may also include one or more dialkylsulfoxides and/or dialkylsulfones. Preferred are dimethylsulfoxide and dimethylsulfone. The solvent system may also include one or more ketones, ethers, and esters. Examples include acetone, methylethylketone, dimethylether, diethylether, dibutylether, and alkyl acetates, alkyl proprionates, alkyl butyrates, and the like.

Although solutions of Applicants' composition described above are preferred, emulsions are also effective. Such emulsions may be aqueous, wherein the aqueous phase is the major and continuous phase, or non-aqueous, wherein water may be present in less than about 10 percent by weight. Applicants' composition may also contain agents known to accelerate the delivery of therapeutic agents through the skin or mucosa. These agents are sometimes known as penetration enhancers, accelerants, adjuvants, and sorption promoters, and are collectively referred to herein as "enhancers." Some examples of enhancers include polyhydric alcohols such as dipropylene glycol; oils such as olive oil, squalene, and lanolin; polyethylene glycol ethers and fatty ethers such as cetyl ether and oleyl ether; fatty acid esters such as isopropyl myristate; fatty acid alcohols such as oleyl alcohol; urea and urea derivatives such as allantoin; polar solvents such as dimethyldecylphosphoxide, methyloctylsulfoxide, dimethylacetonide, dimethyllaurylamide, dodecylpyrrolidone, isosorbitol, decylmethylsulfoxide, and dimethylformamide; salicylic acid; benzyl nicotinate; bile salts; higher molecular weight aliphatic surfactants such as lauryl sulfate salts. Other agents include oleic acid and linoleic acids, ascorbic acid, panthenol, butylated hydroxytoluene, tocopherol, tocopheryl acetate, tocopheryl linoleate, propyloleate, isopropyl palmitate, oleamide, polyoxyethylene lauryl ether, polyoxyethylene olelyl ether and polyoxyethylene oleyl ether.

In one embodiment, these skin penetration enhancers are present from about 0.01 weight percent to about 5 weight percent. In other embodiments, Applicants' composition includes skin penetration enhancers in an amount less than about 0.01 weight percent. In alternative embodiments, Applicants' composition includes skin penetration enhancers in an amount greater than about 5 weight percent.

Applicants' composition may be directly applied to the skin in the form of a low viscosity solution / emulsion. In another embodiment, thickeners or gelling agents may optionally be added to form a gel or cream. In yet another embodiment, Applicants' formulation may be incorporated into a transdermal delivery system such as a patch.

A delivery system of this embodiment can be prepared using conventional methods to apply an appropriate carrier to an appropriate backing. For example, a composition-inadhesive device can be prepared by using the following method; preparing a coating formulation by mixing a solution of the adhesive in a solvent system containing Applicants' composition, and any other desired components, to form a homogeneous solution or suspension; applying the formulation to a substrate such as a backing or a release liner; using well known knife or bar or extrusion die coating methods; drying the coated substrate to remove the solvent; and laminating the exposed surface to a release liner or backing. Applicants' invention further includes a method to increase the weight gain of juvenile swine. The following example is presented to further illustrate to persons skilled in the art how to make and use the invention and to identify a presently preferred embodiment thereof. This example is not intended as a limitation, however, upon the scope of the invention, which is defined only by the appended claims.

EXAMPLE I Ten sows (similar in age, reproductive status, etc.) with at least eight (8) piglets (given birth by the same sow) were selected for use. Four treatments were assigned to the 4 piglets closest to the mean litter weight from the litter of each sow. In addition to other standard procedures (needle teeth clipping, tail bobbing, etc.) on day 3 after farrowing, each juvenile swine was given a unique ear notch, stratified by body weight, and the following treatments were assigned randomly to pigs within stratified body weights:

Positive Control: 150 milligrams of elemental iron dextran injection Negative Control: Saline injection of equal dose to positive control, saline applied in similar manner as the transdermal treatments Treatment 1: Saline injection of equal dose to control, 150 milligrams of elemental transdermal iron gluconate formulation Treatment 2: Saline injection of equal dose to control, 150 milligrams of elemental transdermal iron dextran formulation 2

Stratified Treatment Assignment: - Treatments were assigned randomly to piglets that have been stratified by body weight within each sow.

Sow A Sow B Sow C

Piglet Weight Rank Treatment Piglet Weight Rank Treatment etc.

1 PCon 2 PCon

2 Trt l 3 Trt l

3 Trt 2 4 Trt 2

4 Neon 1

Neon Treatments were applied by rubbing (back and forth 10 times) a predetermined amount (5 ml) of the transdermal solution (or saline) on the skin of the piglets. The piglets were isolated for 15 minutes to prevent cross contamination. Body weights were collected immediately before treatments were applied (day 0) and at the same time of day on the following days: 1, 2, 4, 8, and 12. Table I summarizes the weight gain data obtained in EXAMPLE I.

TABLE I

Negative Positive Iron

Days Control Control Gluconate Iron Dextran # Sows

0 3.480 3.420 3.540 3.430 6

1 3.500 3.620 3.740 3.650 6

2 3.933 3.933 4.008 3.867 6

4 4.467 4.483 4.550 4.383 6

8 5.775 6.100 6.917 6.188 4

12 6.533 7.333 8.467 7.550 3 FIG. 1 graphically depicts the weight gain data recited in Table I. As is readily apparent, transdermal administration of iron gluconate produced the largest weight gains, followed by transdermal administration of iron dextran. Injection of iron dextran resulted in less weight gain than did transdermal administration of either iron gluconate or iron dextran. Injection of saline resulted in the least weight gain. FIG. 2 graphically depicts the percent overall weight gain for the four treatment protocols studied. FIG. 2 shows that transdermal administration of iron gluconate resulted in about a 140 percent overall weight gain over twelve days. Transdermal administration of iron dextran resulted in about a 120 percent overall weight gain over twelve days. The positive control and the negative control treatment protocols resulted in about a 114 percent overall weight gain and about an 88 percent overall weight gain, respectively.

FIG. 3 graphically depicts the incremental percentage weight changes resulting from each of the four treatment protocols studied. In each case, the largest incremental weight gain was seen between day 4 and day 8. Transdermal administration of iron gluconate showed the largest percentage incremental weight of about 52 percent between days 4 and 8. Transdermal administration of iron dextran showed about a 41 percent weight gain over that same time period.

While the invention has been described in detail herein in accordance with certain preferred embodiments thereof, many modifications and changes therein my be effected by those skilled in the art. Accordingly, it is intended by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention.

Claims

We claim:

I . A method to treat juvenile swine anemia, comprising transdermally administering to one or more juvenile swine in need thereof a therapeutically effective amount of iron.

2. The method of claim 1, wherein said iron comprises iron gluconate.

3. The method of claim 1, wherein said iron comprises iron dextran.

4. The method of claim 1 , wherein said iron comprises ferrous methionine.

5. The method of claim 1, wherein said iron comprises ferrous methionine and ferric methionine.

6. The method of claim 1, further comprising the step of transdermally administering between about 50 milligrams and about 300 milligrams of iron to said one or more juvenile swine.

7. The method of claim 6, further comprising the step of transdermally administering about 50 milligrams of iron to said one or more juvenile swine.

8. The method of claim 1, further comprising the step of transdermally administering one or more amino acids to said one or more juvenile swine.

9. The method of claim 8, wherein said one or more amino acids are selected from the group consisting of histidine, lysine, and cysteine.

10. The method of claim 1, further comprising the step of transdermally administering Vitamin E to said one or more juvenile swine.

I I . The method of claim 10, further comprising the step of transdermally administering up to about 5000 IU of said Vitamin E to said one or more juvenile swine.

12. The method of claim 10, further comprising the step of transdermally administering selenium to said one or more juvenile swine.

13. The method of claim 12, further comprising the step of transdermally administering up to about 5 milligrams of said selenium to said one or more juvenile swine.

14. The method of claim 1 , further comprising the step of transdermally administering Vitamin C to said one or more juvenile swine.

15. A method to treat juvenile swine anemia, comprising transdermally administering to one or more juvenile swine in need thereof a therapeutically effective amount of iron in combination with a therapeutically effective amount of copper.

16. The method of claim 15, wherein said copper comprises a copper / lysine complex.

17. The method of claim 16, further comprising the step of transdermally administering between about 150 to about 200 milligrams of said copper / lysine complex to said one or more juvenile swine.

18. The method of claim 15, further comprising the step of transdermally administering Vitamin E to said one or more juvenile swine.

19. The method of claim 18, further comprising the step of transdermally administering up to about 5000 IU of said Vitamin E to said one or more juvenile swine.

20. The method of claim 18, further comprising the step of transdermally administering selenium to said one or more juvenile swine.

21. The method of claim 20, further comprising the step of transdermally administering up to about 5 milligrams of said selenium to said one or more juvenile swine.

22. The method of claim 15, further comprising the step of transdermally administering Vitamin C to said one or more juvenile swine.

23. A method to treat juvenile swine anemia, comprising transdermally administering to said one or more juvenile swine in need thereof a therapeutically effective amount of iron in combination with a therapeutically effective amount of zinc.

24. The method of claim 23, wherein said zinc comprises a zinc / lysine complex.

25. The method of claim 24, further comprising the step of transdermally administering between about 300 milligrams to about 600 milligrams of said zinc / lysine complex to said one or more juvenile swine.

26. The method of claim 23, wherein said zinc comprises a zinc / methionine complex.

27. The method of claim 26, further comprising the step of transdermally administering between about 300 milligrams to about 600 milligrams of said zinc / methionine complex to said one or more juvenile swine.

28. The method of claim 23, further comprising the step of transdermally administering to said one or more juvenile swine a therapeutically effective amount of copper.

29. The method of claim 28, further comprising the step of transdermally administering Vitamin E to said one or more juvenile swine.

30. The method of claim 29, further comprising the step of transdermally administering selenium to said one or more juvenile swine.

31. The method of claim 30, further comprising the step of transdermally administering one or more amino acids to said one or more juvenile swine.

32. A method to increase the body weight of juvenile swine, comprising the step of transdermally administering a therapeutically effective amount of iron to said swine.

33. The method of claim 32, further comprising the step of disposing on the skin of said one or more juvenile swine a solution comprising about 150 milligrams of iron.

34. The method of claim 32, wherein said iron comprises iron gluconate.

35. The method of claim 32, wherein said iron comprises iron dextran.

36. The method of claim 32, wherein said iron comprises ferrous methionine.

37. The method of claim 32, wherein said iron comprises ferrous methionine and ferric methionine.