Compositions for the administration of hyaluronic acid to mammals.

0001The present invention relates to the finding that a known therapeutic agent, hyaluronic acid, can be effectively administered to mammals using techniques that require the processes inside the mammalian body to deliver this high molecular agent to the site of action.

0002Hyaluronic acid is a well-known mucopolysaccharide found in the joint tissue and in the glass liquid (humor vitreus) of the mammalian eye. It is extracted from cockscombs and human umbilical cords as well as from bacterial cultures such as those of streptococci of the hemolytic groups A and C for various therapeutic purposes. The original therapeutic use of this substance was as a replacement for the glass liquid of the human eye to support eye surgery, particularly in the treatment of retinal detachment. It is also used to relieve trauma or irritation in joint tissues of mammals, including humans, by injection into synovial synovial fluid. It has been suggested to use it as a primary drug as well as an adjunct with other joint drugs. A detailed discussion of their various uses can be found in U.S. Patent 4,141,973.

0003The use of hyaluronic acid alone and with cortisone in various joints of animals, in particular horses, is described in the article "Effect of Intra-articular Injection of Hyaluronic Acid on the Clinical Symptoms of Osteoarthritis and on Granulation Tissue Formation" by Rydell et al ., appeared on pages 25 to 32 of the October 1971 issue (No. 80) of Clinical Orthopedics and Related Research. The use of hyaluronic acid in human joints is reported in the article "Preliminary Clinical Assessment of Na Hyaluronate Injection into Human Arthritic Joints" by Peyron et al., Published on pages 731 to 736 of the volume <u style="single">22</u>, No. 8, October 1974, from Pathology Biology. Finally, about the use of hyaluronic acid in reducing fibrotic wound response in "Decreased Granulation Tissue Reaction After Installment of Hyaluronic Acid" by Rydell, published on pages 307 to 311 of the volume<u style="single">41</u> the Acta Orthop. Scandinav., Reports.

0004The intra-articular application of hyaluronic acid in horse joints was promoted economically in connection with the products Hylartil® and Hylartin V® from Pharmacia and Synacid from Sterivet. However, the economic attractiveness was limited due to the need to inject these products by injection into the diseased joint.

0005A related material, a polysulfated glycosaminoglycan, was recently launched in the US by Luitpold Pharmaceuticals under the trade name Adequan® (also known in Europe as Arteparon®) for the treatment of arthritic joints in horses. Initially, the recommended route of administration was intra-articular with an injection of 250 mg per week for 5 weeks. Pages 446 and 447 of the April 1984 issue of Veterinary Medicine suggest that this material can be administered intramuscularly at about twice the dose at four day intervals over a period of about 4 to 5 weeks.

0006Polysulfated glycosaminoglycans have been reported to stimulate the biosynthesis of hyaluronic acid in the synovial membranes of rabbit knee joints, suggesting that although the mode of action may be different from that of hyaluronic acid, the same conditions could be favorably induced. Interestingly, the report "Influences of Sulfated Glycosaminoglycans on Biosynthesis of Hyalu ronic Acid in Rabbit Knee Synovial Membrane" by Nishikawa et al., Published on pages 146 to 153 of the July 1985 edition, volume <u style="single">240</u>, by Arch. Biochem. Biophys., That hyaluronic acid itself has no such stimulating effect.

0007The stimulant is reported to be effective when administered either intramuscularly to humans or subcutaneously to rats. The former effect is demonstrated in "Comparison of glycosaminoglycan polysulfate (arteparon) and physiological saline in osteoarthritis of large joints. Results of a multicenter double-blind study" by Siegmeth et al., Published on pages 223 to 228 of the July / August 1983 edition (volume<u style="single">42</u>, No. 4) the Z. Rheumatol .. The latter effect is discussed in "The animal gonarthrosis of the rat and its therapy with glyco-amino-glycan polysulfate" by Buchmann et al., Published on pages 100 to 107 of the edition 1985 (volume <u style="single">44</u>, No. 3) of the Z. Rheumatol ..

0008The stimulant is also reported to have a wide range of low molecular weights. Mikulikova's "Influence of a Glycosaminoglycan Polysulfate (Arteparon) on Lysosomal Enzyme Release from Human Polymorphonuclear Leucocytes", published on pages 50 to 53 of the March / April 1982 edition (volume<u style="single">41</u>, No. 2) of Z. Rheumatol., There is an indication that arteparon can be fractionated into fractions that have molecular weights between 3,000 and 17,000. In "Polysulfated Glycosaminoglycan: a New Intra-Articular Treatment for Equine Lameness" by Hamm, Goldmann and Jones, published on pages 811 to 816 of the June 1984 edition of Veterinary Medicine, it is reported that adequan has an approximate average molecular weight of 10,000 .

0009The polysulfated glycosaminoglycan is used with a dose recommendation of 250 mg for intra-articular administration to horses. Hyaluronic acid is used at a recommended dose of 20 mg for intra-articular administration. Although it has been reported that polysulfated glycosaminoglycan can be administered intramuscularly at double doses (500 mg), a similar effect was not expected for high molecular weight sodium hyaluronate.

0010Sodium hyaluronate was not expected to be amenable to remote administration (delivery remote from the intended site) because its primary effect was believed to be lubrication and its molecular weight, which is typically well above 1 x 10⁶ u (1 x 10⁶ Dalton). Rather, it was expected that molecules with such a molecular weight would be too large for transfer through mammalian tissue to the distant trauma site. It was thus assumed that effective doses of sodium hyaulronate could not be transported through the mammalian body to the site of action when the doses were given in a reasonably dimensioned manner.

0011It has now been found that the remote administration of hyaluronic acid is effective in reducing the pain and swelling of traumatized or irritated mammalian tissue, in particular joint tissue.

0012A method has been developed to reduce the sequelae of trauma in irritated or inflamed mammalian tissue by the remote administration of hyaluronic acid or a pharmacologically acceptable salt thereof. (In the following, for the sake of simplicity, the term "hyaluronic acid" is used interchangeably to refer to both the free acid and its pharmacologically acceptable salts, except where expressly stated otherwise). The hyaluronic acid is introduced into the mammalian body at a location other than the location of the traumatized tissue and is effectively transported to the site of action by the processes inside the body. This enables the use of such convenient routes of administration as intramuscular, intravenous, subcutaneous injection and topical application. Two particularly preferred routes of administration are intramuscular injection and topical application in a recognized transdermal vehicle, and such a treatment is particularly amenable to such treatment irritated or inflamed joint tissue.<ul id="ul0001" list-style="none"><li>1 shows a series of graphical representations of the change in the extent of the carpal joint with time after treatment with hyaluronic acid for treated horses and control horses in the case of trauma in the carpal joint induced by Freund's Complete Adjuvant.</li><li>FIG. 2 shows a series of graphical representations of the change in range of motion (ROM) with time after treatment for the same horses as in FIG. 1.</li><li>FIG. 3 shows a series of graphical representations of the change in range of motion (ROM) normalized to the day of treatment with time after treatment for the same horses as in FIG. 1.</li><li>FIG. 4 shows the same series of graphical representations as FIG. 3, but with all ordinate values ​​arbitrarily increased by 23.7% to set the lowest point to 0%.</li><li>FIG. 5 shows a series of graphical representations of the lameness index with time after treatment for the same horses as in FIG. 1.</li><li>FIG. 6 shows a series of graphical representations of the percentage improvement in walking with time after treatment for the same horses as in FIG. 1.</li></ul>

0013Trauma in irritated or inflamed mammalian tissue is reduced by administering hyaluronic acid by any of the established routes of administration, except for direct application to the diseased tissue. A particularly interesting embodiment relates to the treatment of joint tissue. Direct administration of hyaluronic acid includes intra-articular injection, which is a process that requires considerable care and skill in the larger joints of larger mammals, such as the leg joints of horses. The treatment of smaller mammals such as dogs and cats and smaller joints of larger mammals such as human finger joints requires an even greater degree of care and dexterity. Remote administration, such as intramuscular, intravenous or subcutaneous injection or topical application in a transdermal vehicle, is much more convenient and attractive in such cases. The fact that the mammalian body's internal transport systems work to deliver hyaluronic acid to the diseased areas makes it possible to treat other traumatized tissues remotely as well. For example, remote administration can be used to treat other conditions where hyaluronic acid has been used, such as adhesions following surgical procedures associated with incisions and tendon repairs, described in the article by Rydell et al., On pages 25 to 32 of the October 1972 edition of Clinical Orthopedics and Related Research.

0014The hyaluronic acid which can be used in the treatment of irritated or inflamed tissue by remote administration can be of any type which is recognized as being suitable for such purposes. It can be extracted from animal tissues such as cockscombs or umbilical cords or from bacterial cultures such as those from streptococci of the hemolytic groups A and C. It should be pure enough to avoid causing an adverse or toxic reaction in the mammalian tissue under treatment. This means that it is free of pyrogens and has a sufficiently low content of proteins and nucleic acids that no significant immune reaction is triggered. It is preferably of high molecular weight and preferably also has low viscosity for administration by injection. The polymer can be in the form of its free acid or in the form of any pharmacologically acceptable salt.

0015The preferred source of hyaluronic acid is a culture of a suitable microorganism. The application of the cultivation and harvesting methods described in EP-OS 0 144 019 are particularly valuable for obtaining a material with the desired purity and the desired molecular weight. Of the organisms to which these techniques can be used, Group A and C streptococci are preferred, with those of Group C being particularly preferred and Streptococcus equi being most preferred. Further preferred is hyaluronic acid, which according to the teachings of copending US patent application Serial No. 816,548, filed January 6, 1986.

0016Both the protein and amino acid content as well as the hyaluronic acid nucleic acid content should be carefully controlled and controlled since it is known that both exert antigenic activity in mammals.

0017The content of both is expediently monitored and evaluated with the aid of the US extinction, the content of proteins correlating with the optical density at 280 nm and the content of amino acids with the optical density at 257 nm. The former are preferably less than about 1.25 mg / ml, in particular less than about 0.1 mg / ml, and the latter are less than about 0.6 mg / ml, in particular less than about 0.005 mg / ml. In this regard, the absorbance at 280 nm does not differentiate between amino acids and proteins. However, while amino acids alone are not antigenic, they readily complex with hyaluronic acid, and the complex can easily trigger an immune response in mammals. For this reason, it is desirable in the context of the present technique to control the content of both, and it makes sense to specify a maximum content for the combination of the two that correlates with a particular UV absorbance. In a particularly preferred hyaluronic acid, the total amino acid content, measured by means of the o-phthalaldehyde fluorescence technique (which is inevitably associated with the hydrolysis of the protein, if any, back to the amino acids of which it consists) is less than about 0.4 mg / ml and the nucleic acid content is less than about 0.06 mg / ml as measured by the ethidium bromide fluorescence technique.

0018The hyaluronic acid can be used in the form of a free acid or in the form of any pharmacologically acceptable salt. One of the most convenient forms is that of the sodium salt, since this polymer is typically purified by sequential precipitation in ethanol or other organic solvents and dissolution in water, and the sodium salt is particularly suitable for such procedures. Indeed, all of the limit values ​​discussed herein have been developed in terms of purity, viscosity, and molecular weight of the sodium salt, and so have the specific application data discussed below. However, remote administration is equally applicable to other forms such as free acid and potassium salt. For reasons of simplification, the discussion summarizes all these forms under the term hyaluronic acid.

0019The hyaluronic acid should have a high average molecular weight. Although forms of this substance with average molecular weights of 55,000 or less are known, the preferred hyaluronic acid has an average molecular weight of at least 5 x 10⁵ as determined by FPLC (Fast Protein Liquid Chromatography) according to the technique described in copending US patent application Serial No. 816,548, filed January 6, 1986. Average molecular weights above about 1.0 x 10⁶, preferably 1.2 x 10⁶ and in particular above about 1.8 x 10⁶ are particularly preferred. It is further preferred that the hyaluronic acid have a relatively narrow molecular weight distribution, and distribution with only a single peak of gel permeation is particularly preferred. A molecular weight distribution with a symmetrical FPLC peak, in which 98% of the molecules have a weight between approximately 1.2 x 10⁶ and 4.0 x 10⁶, is particularly preferred.

0020The hyaluronic acid can have either a high or a low viscosity, depending on the expediency for the desired route of administration. The higher viscosities are expedient for topical applications, while the lower viscosities are particularly suitable for the administration routes by injection, ie intramuscular, intravenous or subcutaneous administration. The higher molecular weight hyaluronic acid can advantageously have viscosities between about 900 and 5000 cSt at 37 ° C for topical applications and advantageously viscosities of less than about 500 cSt, preferably less than about 150 cSt, at 37 ° C for other routes of administration. In both cases, the viscosity is expediently measured on an aqueous solution with 1% by weight of the sodium salt in a Cannon-Manning semi-micro viscosimeter in accordance with the regulations in ASTM D 445 and D 2515. The low-viscosity material facilitates to a high degree Measured the administration by the route of the injection, since, for example, the use of an appropriately concentrated aqueous sodium hyaluronate solution makes it possible to adjust the dosages in practice. So a 1 percent. Use aqueous solution of sodium hyaluronate in a simple manner for injection doses of about 10 ml, which contain about 100 mg of the active ingredient, provided its viscosity is less than about 200 cSt at 37 ° C.

0021Treatment of irritated or inflamed mammalian tissue by remote administration requires a dose or total dose regimen that is effective in reducing or alleviating the trauma. Preferably at least about 0.02 mg hyaluronic acid per 1 lb. of the body weight of the mammal being treated, which is about 0.044 mg / kg. It is particularly preferred to use approximately 0.088 mg / kg (0.04 mg / lb.) And especially 0.176 mg / kg (0.08 mg / lb.), Based on body weight. In the case of topical application, it is particularly desirable to be greater than about 0.22 mg / kg (0.10 mg / lb.), Especially about 0.33 mg / kg (0.15 mg / lb.) body weight.

0022Since hyaluronic acid is a naturally occurring substance in mammals, it is believed that there is no natural upper limit for the tolerable dose. As with all medical treatments, however, it is wise and careful not to use more than is necessary to achieve the desired effect. Furthermore, there is a risk that impurities which are present in sufficiently low concentrations so that they are well tolerated at the effective doses can cause harmful reactions at unjustifiably high doses.

0023The topical treatment should be given in the form of a combined application of hyaluronic acid with a compatible transdermal vehicle. Any recognized carrier such as methyl salicylate, sodium salicylate, benzyl alcohol, oleic acid, 10 percent. Propylene glycol, 1 percent Sodium glycolate, 1 percent. Polyoxyethylene 10 cetyl ether, 0.1 percent. Sodium EDTA, 1 percent Sodium dodecyl sulfate or dimethyl sulfoxide (DMSO) is suitable, with DMSO being particularly preferred. A suitable formulation for application is a mixture of an aqueous solution of less than about 3% by weight hyaluronic acid, in particular as sodium hyaluronate, with an effective amount of a transdermal carrier. A preferred formulation relates to an aqueous solution with between about 0.5 and 2.5% by weight hyaluronate and up to about 30% by volume of the transdermal carrier. The hyaluronate solution and the overall formulation both advantageously show viscosities above about 1000 cSt at 37 ° C.

0024The present treatment has been found to be particularly effective in treating limb pain of large mammals, including pain caused by arthritic conditions. Particularly preferred use forms relate to the treatment of horses and humans by intramuscular injection and topical administration in a transdermal vehicle. A particularly effective treatment for limb pain in the leg joints, in particular in the carpal joint and in the tibiotarsal joint (or ankle joint) of horses, is an intramuscular injection, preferably into the cervical muscle. A particularly effective treatment for musculoskeletal pain in humans is topical application in a transdermal vehicle such as dimethyl sulfoxide (DMSO). The application can take place in the vicinity of the diseased joint tissue, but also at a considerable distance from it.

0025The remote administration techniques of the present invention can also be used to alleviate other conditions against which hyaluronic acid is recognized to be effective. This includes reducing or preventing adhesions at sites of surgery, particularly surgery that affects tendons.

0026The remote administration techniques of the present invention are of particular interest with respect to those mammals which are generally considered to be human companions. The improvement in pain or discomfort of these animal companions of humans is of the greatest interest and of the greatest practical importance among all mammals that are principally accessible to treatment. Cats, dogs and horses are of particular interest in this group.

0027The present invention is illustrated by the following examples, but is not limited to these.

example 1

Investigation of intramuscular treatment of horses

0028A study of eight mares and mixed breed geldings was conducted to determine whether intramuscular administration of sodium hyaluronate is able to relieve symptoms induced by intra-articular injection of Freund's Complete Adjuvant into the intercarpal joint. This is a general and well-accepted model for examining body aches, especially arthritic conditions, in horses. The examination showed that three intramuscular injections of 0.176 mg / kg (0.08 mg / lb.), Based on the weight of the treated horse, into the cervical muscle 5, 9 and 13 days after the initiation of the limb pain with a 0.7 ml injection of the adjuvant were effective.

0029The eight horses were first used to the stables and testing equipment for several days and then examined to establish a basic assessment in relation to the test criteria of joint circumference, range of motion, walking and lameness. The following day, all eight horses were injected with 0.7 ml Freund's Complete Adjuvant into the left intercarpal joint. The horses showed pain in the left front leg for the next four days. On the fourth day after the intra-articular injection of the irritant, the horses were examined again for the same four criteria. An overall score was developed for each horse, which consisted of the sum of the differences between the two measurements of each parameter (excluding stride). These values ​​were then used to assign four horses to a control group and four horses to a treatment group in such a way that the horse with the highest value in one group, the horses with the next two higher values ​​in the other group and the horses with the two following next higher values ​​of the first group, which were assigned two horses with the following values ​​of the second group and the last horse of the first group. The first group was determined by randomly throwing a coin as a control group. The measurement table looked as follows, the measurement days being arbitrarily designated as -6 and -1.<tables id="tabl0001" num="0001"><img file="EP0243867A2_D0001.tif" /></tables><tables id="tabl0002" num="0002"><img file="EP0243867A2_D0002.tif" /></tables>

0030The next day (day 0), each of the horses was injected between 7.5 ml and 9.5 ml, depending on their body weight, into the cervical muscle. Each horse received an injection, rounded to the nearest 0.5 ml, of 0.0176 ml / kg (0.008 ml / lb.) Based on body weight. The injection for the horses in the treatment group consisted of a sterile aqueous solution with 1.19% by weight sodium hyaluronate with an average molecular weight of 1.88 × 10⁶ determined by means of FPLC, a nucleic acid content of less than 0.003 mg / ml by means of ethidium bromide Fluorescence, a total amino acid content by means of o-phthalaldehyde fluorescence of less than 0.005 mg / ml and a viscosity of 147 cSt at 37 ° C, while the injection for the control group horses consisted of a sterile phosphate buffered saline solution. The weight of each horse and the dose given to it at that time and four and eight days later were as follows:<tables id="tabl0003" num="0003"><img file="EP0243867A2_D0003.tif" /></tables>

0031The injection site was sensed and body temperature was measured three days a day after the first injection, at the time of the second injection and at the time of the third injection, and finally four days after the third injection. IM treatment did not cause any harmful effects. All temperatures remained normal and there was no clinically significant reaction at the injection site (Freund's Complete Adjuvant is a "known pyrogen", so the normality of the temperature was assessed due to the fact that the treatment injections caused no further temperature rise and did not appear to interfere with the drop in temperature from the peak induced by the traumatizing injection.

0032Each horse was evaluated 7, 14, 21, 28, 35 and 42 days after the first injection according to the criteria of joint circumference, range of motion, length of walking and observed lameness. These were the same parameters that had been used to classify the horses into the treatment group and the control group.

Carrying out the assessment

1. Joint circumference

0033The joint circumference was measured while the animal was still in the box before work. It was measured at a point immediately above the accessory carpal bone. It was measured with a cloth tape and recorded in cm.

2nd Range of motion

0034The range of motion was measured in the box. It is given by the difference between the angle of the diseased leg at rest and the bending angle. All three values ​​were recorded. A goniometer was used to determine the angles.<ul id="ul0002" list-style="none"><li>a. Leg at rest: The angle of the carpus was measured on the horse in a standing position using the goniometer.</li><li>b. Bend angle: The diseased joint was bent while the leg was lifted off the floor. The goniometer was used to measure the angle at which the horse reacted to bending by dodging, shy or pulling back.</li></ul>

3rd Length of stride

0035The stride length was measured before the horse was placed on a walking machine. A long roll of paper (6 m; 20 feet) was used to record the distance between the marks on the hooves. Before walking over the paper, the hoof of the diseased leg was smeared with water or mineral oil. Two steps were recorded and the distance between hoof markings on the diseased leg was measured in cm. The horse was let go over the paper three times. An average of the three measurements was used as the final value.

4th Observed lameness

0036The horse was placed on the mechanical walking machine and allowed to walk for 5 minutes at a speed of 9.6 km / h (6 mph). The evaluation is made while the horse is on the walking machine. The direction of the mechanical walking machine was adjusted so that the affected leg was on the inside. 0 = no lameness. 1 = difficult to observe; not consistently occurring regardless of the circumstances (ie Carrying weight, walking in a circle, crooked, hard surface etc.). 2 = difficult to observe when walking or trotting in a straight direction; Consistently occurring under certain circumstances (ie carrying weight, walking in a circle, crooked, hard surface etc.). 3 = consistently occurring when trotting under all conditions. 4 = obvious lameness, pronounced nodding, limping or shortened step. 5 = minimal weight load when moving and / or at rest; Inability to move. If a horse strongly opposed the movement and placement on the mechanical walking machine was not advisable, a rating of 5 was recorded and the horse was returned to the box.

0037An analysis of these parameters clearly showed the favorable result of the intramuscular hyaluronic acid injections for the relief of the trauma induced by the Freund's Complete Adjuvant. The horses in the treatment group showed clearly superior behavior in the test in all parameters with the exception of the joint circumference compared to the horses in the control group, for which results were not so conclusive. This is in line with other studies on the improvement of trauma in horse joints, in which it was found that the joint circumference is not a particularly sensitive measurement parameter. The results are summarized in the table below, in which "day" denotes the number of days before or after the first injection:<tables id="tabl0004" num="0004"><img file="EP0243867A2_D0004.tif" /></tables><tables id="tabl0005" num="0005"><img file="EP0243867A2_D0005.tif" /></tables>

0038Analyzes of these results were recorded for each of the parameters along with some intra-articular treatment of the joints of horses similarly traumatized by injection of Freund's Complete Adjuvant. However, the induced trauma was somewhat less severe than that of the present invention, so that the control horses from this study had a range of motion that was not too different from the treatment horses of the present study. More importantly, however, the difference in regaining range of motion and the decrease in lameness between the treatment and control horses for the present study was closely parallel to that observed in the previous study. Thus, the effects achieved by intramuscular injection were very similar to those previously achieved by intra-articular administration.

0039The analyzes are shown in FIGS. 1 to 6. In these figures, the empty squares represent the mean values ​​for the four treatment horses, and the empty triangles represent the mean values ​​for the four control horses of this study. The hexagons and the hatched squares indicate the mean values ​​for horses with a similarly induced Gelenek trauma, which intra-articularly with a single dose of 40 mg or 20 mg of a similar aqueous sodium hyaluronate solution was treated, while the hatched triangles represent the mean values ​​for the untreated control horses used in this earlier study.

0040Fig. 1 shows the changes in the "joint circumference" from the day before the first injection to the end of the examination 43 days later {for reasons of simplification, the "Day-1" is plotted on the 0 axis and represents the increase in the joint circumference ( in inches) since the day before the traumatizing injection, ie day -6. Although the swelling of the joints is never completely reversible, the hyaluronic acid treatment stabilizes or partially alleviates them at a low level. The effect is somewhat less dramatic with the present (intramuscular) route of administration, but it is clearly present and shows up on joints for which the other parameters indicated that they were more traumatized than those that were treated intra-articularly.

0041FIG. 2 shows the changes in the "range of motion" (ROM) during the same period as in FIG. 1. The value 100% is based on the ROM found on the day before the traumatization, ie day -6. It is clear that the joints examined in the intra-articular comparative study were less traumatized because the disability of the ROM before treatment was less severe.

0042It also becomes clear that the intramuscular treatment and the intra-articular treatment have brought about parallel improvements over their respective controls. However, since Freund's Complete Adjuvant causes extreme trauma, neither the treatment according to the invention nor the comparative treatment were able to completely alleviate the induced state.

00433 and 4 show further analyzes of the ROM data in which the percentage improvement compared to the state on the day before the first injection treatment is evaluated. The time scale is the same as in FIG. 1 and FIG. 2. In FIG. 4, the graphical representation has been shifted upwards arbitrarily by adding 23.7% to all ordinate values. Here it appears that the intramuscular administration according to the present invention results in a greater improvement over its control than is the case with the intra-articular administration.

0044Figure 5 shows the change in "observed lameness" during the same period as the previous figures. The intramuscular route of administration and the intra-articular route of administration showed approximately equivalent effects. The controls for the present study showed a somewhat higher degree of lameness, suggesting that the traumatization for the present study was somewhat more severe than that for the previous intra-articular study. The fact that the same level of lameness was achieved with both routes of administration indicates that the route could be somewhat more effective in accordance with the present invention.

0045Figure 6 shows the change in "stride length" during the same period as the previous figures. The step was compared to the mean observed on the day before the traumatizing injection, ie day -6, for each assessment, yielding a percentage of recovery. Both the horses treated according to the present invention and the horses treated by intra-articular injection show a faster recovery and a higher degree of final stride recovery compared to their respective controls.

Example 2

0046Back pain in a man, age 48, weight 70 kg (155 lbs.), Was alleviated by topical application of an aqueous solution of sodium hyaluronate mixed with 10 to 30% by volume of dimethyl sulfoxide (DMSO). Specifically, preparations were made with 10, 20 and 30 vol .-% DMSO, in which the rest of each determined from a solution of 1.7 wt .-% sodium hyaluronate with a viscosity above 500 cSt at 37 ° C and one using FPLC Molecular weight of 2 x 10⁶ u (2 x 10⁶ daltons) and a m nucleic acid content of 0.00137 mg / ml and a total amino acid content, determined by o-phthalaldehyde fluorescence, of 0.0047 mg / ml. Applications of approximately 2 ml of the preparation were carried out on the back in the vicinity of the painful area twice a day for a period of 2 weeks. In each case, the pain was relieved in about 15 minutes and this relief continued for about 8 to 10 hours. Then the treatment was temporarily interrupted and the pain returned after about 4 to 5 days. At that time, treatment was resumed by daily application of about 2 ml of the preparation to the wrists, and effective pain relief was achieved. This treatment was discontinued after three days and the pain did not return for the next two and a half weeks. Accordingly, the pain was effectively treated with a topical dose of about 0.33 mg / kg body weight (0.15 mg / lb.) (2 ml x 1.7% by weight x 70% by volume x 1000 mg / ml ) that has been applied either near the painful area or in a more distant place.

0047The pain relieved in this way had been almost constant for about two years before the start of treatment. After the pain treatment, the pain was felt to a much lesser extent only after sitting or sleeping for a long period of time in a constant position.

0048Topical application of sodium hyaluronate without a transdermal vehicle was ineffective. The sodium hyaluronate solution simply evaporated to dryness, leaving a film on the patient's skin.

0049The administration of equivalent amounts of DMSO alone was also ineffective in relieving back pain. In fact, it caused some irritation to the area of ​​the skin to which the DMSO had been applied. This was in marked contrast to the use in combination with the sodium hyaluronate solution, in which no skin irritation was observed.

Example 3

0050Various joint and muscle pains were reduced in a man, age 54, weight 113 kg (250 lbs.) By topical application of the same aqueous sodium hyaluronate solution as used in Example 2 combined with 20% by volume DMSO , based on the total volume, alleviated. A knee that was painful from cartilage damage that was several years old was treated with 4 ml of this preparation and relief was felt within 30 minutes. The treatment was repeated at four daily intervals, which successfully controlled the pain for about two weeks. Shoulder bursitis pain was successfully relieved within a few minutes of topical application of approximately 5 ml of the same preparation. The pain returned after about four days and was relieved by the same treatment. The cycle was repeated four times. Sore muscle pain in the clavicle area was alleviated by using 3 ml of this preparation. The application was only on one side and the pain persisted on the other side.

Example 4

0051Severe back pain in a man, age 57, weight 88.5 kg (195 lbs.), Who suffered from multiple herniated discs in the lumbar region with the resulting muscle cramps, was reduced by the topical application of 2 ml of the preparation described in Example 2 20 vol.% DMSO relieved. The preparation was applied to the skin over the lumbar spine and relieved the pain within an hour for about eight hours. The treatment was carried out at 12-hour intervals over a period of several days, with occasional treatment being skipped. The treatment was ineffective on some occasions, but in such cases the subsequent treatment was effective.

0052The condition under treatment had previously been treated by enzyme injection therapy for more than one year. Electrosurgery was considered at the time of initiation of the present treatment.

Example 5

0053Two quarter-horse riding horses, which normally actively participated in barrel races, developed tendonitis of the flexor tendons of both hind legs and were successfully treated by topical application of the aqueous sodium hyaluronate solution of Example 2 in admixture with a transdermal vehicle. The mixture of 80% by volume sodium hyaluronate / 20% by volume dimethyl sulfoxide was more effective than a commercially available topical agent, absorbents. One leg of each horse was treated with the hyaluronate mixture and the other leg was treated with absorbins. The hyaluronate was applied twice a day for three days, applying 3 ml on the first day and 1 ml on the following two days (in each case half of each application was applied to either side of the leg) . At the end of the three days, the symptoms, swelling over the tendon and vagina and sores over the sesame bone were eliminated. The primary lesion was gone. On the other hand, treatment with Absorbine in the recommended manner required six days of treatment to the point of full improvement.

Comparative Example 1

0054Two trials were performed that showed a limitation in the remote administration of hyaluronic acid. Two of the control horses from the study reported in Example 1 were treated topically and two others were treated intravenously after their trauma became chronic and no significant improvement in their condition was observed. Although some relief of the chronic condition induced by Freund's Complete Adjuvant by intra-articular injection of sodium hyaluronate has been reported in EP-OS 0 144 019, this model is generally limited to the study of the treatment of acute conditions. The lesions developed long after the traumatization are so severe that they are not normally expected to respond to treatment. Because of this, these results are not seen as a serious limitation of remote administration and can actually be classified as reflecting the severity of the induced trauma.

0055The topical treatment was carried out once a day for six days, starting on "Day 28" of the examination of Example 1, ie 34 days after the induction of trauma, by applying 10 ml of a mixture of 80% by volume sodium hyaluronate / 20% by volume. % Dimethyl sulfoxide on the diseased joint. The aqueous hyaluronate solution was the same as that used in Example 2. No significant improvement was observed in any of the four criteria of Example 1, both compared to the condition immediately before treatment and compared to the other two control horses.

0056The intravenous treatment was carried out every other day for eight days starting from "Day 35" of the examination of Example 1, ie 41 days after the induction of trauma, by injecting 4 ml of the aqueous sodium hyaluronate solution used in Example 1 into the jugular vein . Again, no significant improvement was observed in any of the four criteria.