Topical wound therapeutic compositions

There is provided a composition for healing burns and wounds in mammals which contains the combination of hyaluronic acid and a serine protease inhibitor. Advantageously, elements found in amniotic fluid are also included.

BACKGROUND OF INVENTION
 1. Field of the Invention
 This invention relates the treatment of burns, open sores, incisions and
 wounds in mammals. In particular it relates to topical wound therapeutic
 formulations containing a hyaluronic acid (hyaluronan) and a serine
 protease inhibitor, preferable in combination with elements found in
 amniotic fluid.
 2. Description of the Prior Art
 Adult wound repair is characterized by fibrosis, scarring, and sometimes by
 contracture. The results of this deforming process affect every form of
 surgery and can have devastating consequences. In contrast fetal wound
 healing proceeds without such fibrosis or scar formation, Michael T.
 Longaker, M.D., Ernie S. Chiu, B.S., N. Scott Adzick, M.D., Michael Stern,
 D.D.S., Michael R. Harrison, M.D., and Robert Stern, M.D., Studies in
 Fetal Wound Healing, V. A Prolonged Presence of Hyaluronic Acid
 Characterizes Fetal Wound Fluid, Ann Surg, April 1991, pp. 292-296.
 It is known that hyaluronic acid bonds with fibronectin and together they
 have a powerful effect on the body's cellular matrix. It is also known
 that urea, produced by the fetus has an effect on cell migration. Elements
 such as glucose, protein, sodium, potassium, calcium, magnesium, phosphate
 and chloride that form the amniotic fluid, work together with an
 inseparable bond and synergy.
 Fibronectin is important in wound healing. However, the presence of certain
 proteases in excess binds with the fibronectin and prevents its activity
 in healing.
 Several prior art patents disclose therapeutic formulations including
 hyaluronic acid. Lindblad, "Hyaluronic Acid Preparation used for Treating
 Inflammations of Skeletal Joints"; U.S. Pat. No. 4,801,619 disclosed the
 use of hyaluronic for intra-articular administration for the treatment of
 steroid arthropathy and progressive cartilage degeneration caused by
 protoglycan degradation. Langerman, "Spare Parts for Use in Ophthalmic
 Surgical Prodecures: U.S. Pat. No. 4,888,016 disclosed the use of
 hyaluronic acid in ophthalmic surgery as an artificial "spare part" for
 surgical implantation in the eye during an extracapsular cataract
 extraction. Alvarez, "Three Step Wound Treatment Method and Dressing
 Therefor"; U.S. Pat. No. 4, 813,942, which is herein incorporated by
 reference, disclosed the use of hyaluronic acid in the third step of a
 three step treatment. The invention calls for hyaluronic acid to be in a
 hydrocolloid dressing which will provide controlled delivery over a period
 of 24 to 96 hours to promote thickening of the epidermal cells, thus
 strengthening the wound. Balazs et al, "Cross-Linked Gels of Hyaluronic
 Acid and Products Containing Such Gels"; U.S. Pat. Nos. 4,582,865,
 4,636,524 and 4,636,865 disclosed the use of cross linked gels of
 hyaluronic acid as a drug delivery system.
 None of these prior art references claim to use hyaluronic acid and a
 serine protease inhibitor in the treatment of burns, open sores,
 incisions, and wounds and there is no combination with calcium, phosphate,
 uric acid, urea, sodium, potassium, chloride, and magnesium to simulate
 amniotic fluid.
 U.S. Pat. Nos. 5,190,917 and 5,290,762, which are herein incorporated by
 reference disclose the roles of serine protease inhibitors in treatment of
 inflammation.
 U.S. Pat. No. 4,970,298 which is herein incorporated by reference discloses
 a biodegradable matrix which comprises collagen, hyaluronic acid and
 fibronectin which enhance healing of wounds. Collagen, which is
 oversecreted by the body in response to an injury or wound, is known to be
 responsible for scar formation. Georgalas et al., "Skin Treatment
 Composition and Method for Treating Burned Skin," U.S. Pat. No. 4,839,019,
 discloses a composition which counteracts moisture loss and promotes
 healing of burned or sunburned skin comprised of polyglycerylmethacrylate,
 glycerine, allantoin, panthenol, amino acid complex, and fibronectin.
 BRIEF SUMMARY OF THE INVENTION
 The invention relates to formulations containing hyaluronic acid and a
 serine protease inhibitor selected from the group consisting of alpha
 1-antitrypsin (AAT), secretory leucocyte protease inhibitor (SLPI) and
 cromolyn. The mixture can be further combined with calcium, phosphate,
 uric acid, urea, sodium, potassium, chloride and magnesium, all elements
 found in amniotic fluid, to provide a unique synergy that is effective in
 the treatment of burns, open sores, incisions and wounds in mammals.
 The invention is used for wound therapeutic formulations useful for topical
 application, useful for treating burns, traumatic damage caused by
 irradiation of the skin, the deleterious effects of open sores, incisions
 and wounds on skin and further provides a mixture which simulates the
 fetal in utero wound healing matrix in a safe and effective amount of a
 topical carrier.
 Hyaluronic acid and the serine protease inhibitor alone in a pharmaceutical
 base are sufficient for treating minor injuries. The additional elements
 comprise a mixture of constituents selected from the group of calcium,
 phosphate, uric acid, urea, sodium, potassium, chloride and magnesium
 which are found in amniotic fluid.
 A preferred topical composition comprises by weight of the mixture: 0.01%
 to 1.50% calcium; 0.01% to 0.10% phosphate; 0.01% to 2.00% uric acid,
 0.01% to 2.00% urea; 0.02% to 1.50% sodium; 0.01% to 0.10% potassium;
 0.01% to 0.70% chloride; 0.001% to 0.01% magnesium; 0.01% to 2.50%
 hyaluronic acid; and 0.01% to 5.00% of a protease inhibitor.
 In the best mode the hyaluronic acid comprises by weight 0.10% to 2.50% of
 the mixture either with the serine protease inhibitors alone or with the
 additional elements.
 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
 The invention is a means for delivery of hyaluronic acid and a serine
 protease inhibitor in a topical preparation for the treatment of burns,
 open sores, incisions and wounds for optimum healing.
 In accordance with the invention, there is provided herein formulations
 useful for topical application comprising hyaluronic acid and a serine
 protease inhibitor alone or in combination with calcium, phosphate, uric
 acid, urea, sodium, potassium, chloride, and magnesium, all elements
 healing matrix and a safe and effective amount of a topical carrier, in
 combinations described below.
 Tissue repair in the mammalian fetus is fundamentally different than normal
 adult healing. In adult humans, injured tissue is repaired by collagen
 deposition, collagen remodeling and eventual scar formation, whereas fetal
 wound healing appears to be more of a regenerative process with minimal or
 no scar formation. The adult wound heals by the replacement of normal
 dermis with a scar that consists of excessive and abnormally organized
 collagen. In marked contrast, the fetal wound contains a persistent
 abundance of hyaluronic acid while collagen deposition is rapid and
 nonexcessive, Bruce A Mast, M.D., Robert F. Diegelmann, Ph.D., Healing in
 the Mammalian Fetus, Surg. Gyn. And Ob., Vol. 174, pp. 441-451, May 92.
 What is known is that hyaluronic acid has a definite role in harnessing and
 manipulating the natural reparative capacity of tissue fibroblasts and the
 hyaluronic acid protein complexes play a significant role in vivo
 organization or scar tissue, D. A. R. Burd, R. M. Greco, S. Regaurer, M.
 T. Longaker, J. W. Siebert and H. G. Garg, Hyaluronan and Wound Healing: a
 New Perspective, Journal of Plastic Surgery, 1991, pp. 579-584.
 Hyaluronic acid has played a very limited role in the care and treatment of
 burns, open sores, incisions and wounds because there has not been an
 effective delivery system that could deliver hyaluronic acid, which is
 found in abundance in amniotic fluid, to the wound site in a manner that
 replicated the moist environment and the other healing benefits discovered
 in amniotic fluid.
 It is understood that the term hyaluronic acid includes its derivatives and
 broadly refers to naturally occurring, microbial and synthetic derivatives
 of acidic polysaccharides of various molecular weights constituted by
 residues of glucuronic acid and N-acetyl-D-glucosamine.
 Serine protease inhibitors, because of their control of elastase, permit
 proper laying down of tissue and can prevent keloid scars. The serine
 protease inhibitor is used in an amount of about 0.5 to 5% by weight of
 the composition.
 The wound healing process is significantly different in adults as compared
 to the healing that takes place in amniotic fluid. Sharply increased
 levels of hyaluronic acid characterize adult wound healing during the
 first three days. By the seventh day, hyaluronic acid is not detectable.
 In adults, wound healing is believed to be accomplished by high levels of
 alpha 1-antitrypsin and it is further believed that it is the elastase
 that is responsible for scarring and needs to be controlled together with
 cathepsin G.
 Fetal wound healing is characterized by sharply increased levels of
 hyaluronic acid during the first three days, but, unlike adult wound
 healing the level of hyaluronic acid remains elevated for 21 days. These
 findings are the result of research conducted by Michael T. Longaker,
 M.D., Ernie R. Harrison, M.D., and Robert Stern, M.D. and reported in an
 article titled Studies in Fetal Wound Healing: V. A. Prolonged Presence of
 Hyaluronic Acid Characterizes Fetal Wound Fluid, in Ann. Surg., April
 1991, pp. 292-296. The graph of their findings as published is shown in
 FIG. 1.
 The healing process of the fetus is controlled by high levels of hyaluronic
 acid and alpha 1-antitrypsin. In adult healing process there is an
 overproduction of elastase which leads to the formation of scar tissue.
 The topical addition of hyaluronic acid and an elastase binding protease
 inhibitor in the wound bed will alter the adult healing process and
 facilitate accelerated healing and reduce the formation of scar tissue.
 The presence of both the hyaluronic acid and alpha 1-antitrypsin protects
 fibronectin from being degraded by elastase and other protases.
 Cell growth stimulating compound, may be incorporated into the composition.
 According to the present invention, the human growth hormone is utilized
 in an effective amount of at least about 0.05 ng/ml. Most preferably, the
 cell growth stimulating compound includes a mixture of human growth
 hormone, insulin (containing transferrin or transferrin-free) and/or
 triiodothyronine or thyroxin, each compound in an amount ranging from at
 least about 0.05 ng/ml, preferably at least about 0.5 ng/ml, and more
 preferably at least 1 ng/ml or more. In the case of insulin, the effective
 amount of insulin generally ranges from about 5 ng/ml to about 100 ug/ml
 and more preferably about 50 ng/ml to about 2 ug/ml within this range.
 In addition to effective amount of cellular growth stimulating hormone and
 cellular nutrient media, formulations according to the present invention
 may also contain hydrocortisone, which in certain instances may have a
 beneficial overall effect in enhancing wound healing.
 Hydrocortisone is found to improve the cloning efficiency of fibroblasts,
 enhancing the maintenance of epidermal keratinocytes. The preferred amount
 to be incorporated is generally within the range of about 0.2 umol to
 about 50 umol. The formulations according to the present invention may
 also include an effective amount of an antimicrobial agent, for example,
 antibiotics and antifungal agents, such as griseofulvin and nystatin and
 antiviral agents and the like. The antimicrobial agent may be added for
 its ability to treat an infection, or alternatively, for its prophylactic
 effect in avoiding an infection.
 There are many different carriers which can effect quick delivery to the
 skin. Such delivery system is desirable especially in dogs who have the
 tendency to lick their wounds. Therefore, a liposome which causes a rapid
 infusion into the skin is desirable. One such delivery system is found in
 "Novasome" a trademark for a carrier of Eavsco Corp. of New Jersey.
 Otherwise, an occlusive bandage type of carrier such as vasoline or
 aquaphor can be used.

EXAMPLE 1
 A Therapeutic Skin Lotion
 A therapeutic aqueous skin lotion is prepared by combining the following
 components utilizing conventional mixing techniques.

INGREDIENT PERCENTAGE BY WEIGHT
 Water 90.90%
 Aloe vera extract 2.00%
 Glycerin 2.00%
 PVP 1.00%
 Triethanonmine 1.00%
 Sodium 0.70%
 Hyaluronic Acid 0.50%
 Alpha 1-antitrypsin 0.50%
 Allantoin 0.50%
 Carbomer-940 0.50%
 Chloride 0.50%
 Potassium 0.05%
 Urea 0.06%
 Calcium 0.05%
 Phosphate 0.03%
 Magnesium 0.01%
 EXAMPLE 3
 Into Novasome of Eavsco Corp. is admixed 1.0% by weight of alpha
 1-antitrypsin and 1.0% of hyaluronic acid for use in treating hot spots on
 dogs.
 Many alterations and modifications may be made by those having ordinary
 skill in the art without departing from the spirit and scope of the
 invention. Therefore, it must be understood that the illustrated
 embodiment has been set forth only for the purposes of example and that it
 should not be taken as limiting the invention as defined by the following
 claims. The following claims are, therefore, to be read to include not
 only the combination of elements which are literally set forth, but all
 equivalent elements for performing substantially the same function in
 substantially the same way to obtain substantially the same result. The
 claims are thus to be understood to include what is specifically
 illustrated and described above, what is conceptionally equivalent, and
 also what essentially incorporates the germ of the invention.