GB1571108A

GB1571108A - Surgical sutures

Info

Publication number: GB1571108A
Application number: GB3436876A
Authority: GB
Original assignee: Howmedica Inc
Current assignee: MTG Divestitures LLC
Priority date: 1976-04-12
Filing date: 1976-08-18
Publication date: 1980-07-09
Also published as: JPS52124792A; ES450887A1; AU499780B2; FR2347936B1; DE2638831A1; CH616845A5; CA1083961A; AU1682376A; FR2347936A1; IT1091919B

Description

(54) IMPROVEMENTS IN OR RELATING TO SURGICAL SUTURES (71) We, HOWMEDICA INC., of 235 East 42nd Street, New York, New York, U.S.A., a company organised and existing under the laws of the State of Delaware, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to surgical sutures and provides dyed, or undyed, substantially water-insoluble, biocidal salt-containing sutures of improved pliability and knottability characteristics. More particularly, the invention provides polyfilamentous sutures provided throughout the body of the suture with a neomycin fatty acid salt and, in a preferred embodiment, with a combination of a neomycin fatty acid salt and wax.

With all surgical sutures, it is necessary to consider the ease with which surgeons can handle and knot the sutures as well as the effect of the sutures in the patient's body. It is taken for granted that the most common knotting technique now in use would be preferred by surgeons, that is, the knotting technique employed with surgical silk. If every suture could be made with the same knotting characteristics as surgical silk, it would be optimal for the surgeon.

With all surgical sutures, it is also necessary to consider the effect of the surgical suture when infection is present. It has been found that polyfilamentous sutures (i.e. all sutures other than monofilament sutures and includes sutures of continuous filamentous and sutures of staple filamentous as for instance silk or cotton), as a rule, will have a greater potentiating effect on infection than monofilamentous sutures. See, for instance, "Surgical Sutures and Infection, A Biomaterial Evaluation" by Edlich, R. F., Panek, P. H:, 'Rodeheaver, G. T., Kurtz, L. D. & Edgerton, M. T., Journal qfBiomedical Materials Research, Volume 8, page 115-126, 1974 and "Potentiation of Infection by Suture Closure of Dead Space" by DeHoll, D., Rodeheaver, G., Edgerton, M. T., and Dudley, R.F., American Journal of Surgery, page 716-720, Volume 127, 1974. However, all monofilamentous and polyfilamentous sutures potentiate infection.

In summary the suture should have the "hand" and knottability of standard surgical silk sutures as well as a complete absence of potentiation of infection.

In an attempt to solve these problems, it has been suggested to provide a "Dacron" (R.T.M.) suture i.e. a polyethylene terephthalate suture, which had been coated and impregnated with polytetrafluoroethylene particles. One of the functions of the polytetrafluoroethylene "Teflon" (R.T.M.) particles was to change the knottability of the Dacron surface to approximate to that of standard surgical silk sutures. The other function was to fill the interstices and thereby to transform the polyfilamentous Dacron sutures into a "functional monofilament". A "functional monofilament", it was considered, would have less potentiating effect than the polyfilamentous suture. However, the problem would not be completely solved since all monofilaments do in fact potentiate infection.

It has therefore also been proposed to impregnate sutures with various waterinsoluble biocidal salts, so as to render the sutures bactericidal over long periods of time by virtue of their slow release properties. It is not uncommon to find however that, in the preparation of these long-lasting germicidal sutures, they do not have the "hand" and knotting characteristics of the standard, surgical silk.

Another common problem associated with the preparation of long-lasting biocidal salt-containing sutures is the requirement by surgeons that the sutures be dyed for visibility. Considerable difficulty has been experienced with dye loss during the impregnation of dyed sutures with solutions of the desired biocidal salt.

A similar biocidal salt loss is experienced if the sequence is reversed, that is, the dying step is introduced after impregnation with the biocidal salt.

It is an object of the present invention, therefore, to provide dyed, or undyed, polyfilamentous surgical sutures which are endowed with improved "hand" (softness and flexibility) and knotting characteristics, together with longlasting biocidal properties, without the necessity of the aforementioned addition of polytetrafluoroethylene particles.

Accordingly, the invention provides a surgical suture having a therapeutic and prophylactic effect against bacterial infections, which comprises a soft, pliable polyfilamentous surgical suture having incorporated uniformly throughout and onto the body thereof an amount of a neomycin salt of at least one fatty acid containing from 12 to 18 carbon atoms. The surgical suture of the invention can be obtained by simultaneously dying and impregnating the body of the surgical suture with a neomycin salt.

An important feature of the present invention is the fact that the neomycin salts, despite their high water-insolubility, have been surprisingly found to provide therapeutic and prophylactic effectiveness against a variety of both gram-positive and gram-negative bacteria, as, for instance Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, and the like. Thus, a polyfilamentous suture is provided which carries with it the capability of "clearing" contaminated tissues of the infection within a short period of time (therapeutic effect) and then continuing to offer a persistent reservoir of a water-insoluble antibacterial salt within the suture which offers broad spectrum activity over a long period of time through slow release of the relatively insoluble antibiotic (prophylactic effect).Yet, all of these advantages are provided without so adversely effecting the pliability and knottability characteristics of the suture as to require the provision of softening and knotting aids such as "Teflon" particles.

Another important feature resides in the surprising discovery that a mixture of the neomycin salt and a wax incorporated uniformly throughout the body of the suture gives the advantageous softness, pliability and knotting characteristics of standard surgical silk. Other water-soluble antibiotic salts with the wax, including salts of neomycin, fail to endow the surgical suture with these desirable characteristics. It is also found that the wax causes the neomycin fatty acid salt to lose its brittleness, making it less resistant to flaking, which would have a deleterious effect on dosage.

The reason why the neomycin fatty acid salts of the present invention provide these advantages whereas other antibiotic salts have failed is not completely understood. It is believed that the answer involves several factors, the principal of which are:- 1) the lubricious quality that characterizes the salt, 2) the ability of the salt to solidify into adherent fillings within and around the polyfilamentous suture strand, thereby increasing the tendency of the salt to remain tightly held within both the interstices and on the body of the suture, and 3) the relative waterinsolubility of the salts which, in addition to contributing to their ability to remain within the suture, permits of the slow release of the neomycin so as to provide longlasting biocidal properties.

Whereas the impregnation of polyfilamentous sutures with neomycin fatty acid salt provides the sutures with acceptable softness, pliability and knottability characteristics and the desirable attributes of monofilament, it does have a tendency to make the sutures too slippery. Consequently, knot retention, that is, the ability of the knot to resist slip, in a suture treated with the neomycin fatty acid salts is not so good as it is in a standard surgical silk suture.

According to preferred embodiment of the invention, therefore, the slippery feature of sutures treated with neomycin fatty acid salts is eliminated, or at least substantially alleviated, and the ability of the knotted suture to resist slip to the same degree as a standard silk suture is restored, by providing the surgical sutures with a combination of the neomycin fatty acid salt and a wax. The neomycin salt and the wax may be added sequentially in separate steps with the waxing following the biocide addition. In either case the result is a surgical suture which, when knotted, exhibits essentially the knot slip characteristics of standard surgical silk, as compared for instance with surgical sutures containing the neomycin salt alone which exhibit increased knot slip characteristics as compared to standard surgical silk.

As used in the specification and claims of this application, the term "neomycin" has reference to the antibiotic more fully described in Waksman, Neomycin, The Williams and Wilkins, Co., Baltimore, Md., 1958. The term includes the separate and closely related antibiotics known as neomycin B and neomycin C, and mixtures thereof. The neomycin salts can be formed by reacting a suitable neomycin reactant such as neomycin sulphate and neomycin hydrochloride with a fatty acid reactant in the form of free fatty acid or the alkali metal salts thereof. Suitable fatty reactants include, for instance, palmitic acid, stearic acid, oleic acid, lauric acid, myristic acid, palmitoleic acid, and mixtures thereof.

The neomycin fatty acid salts can be made by merely mixing a solution of the fatty acid reactant in alkanol as a solvent with an aqueous solution of the neomycin.

The reaction can also be accomplished in aqueous solutions of the alkali metal salts of the fatty acid. Generally, for complete reaction, six molar equivalents of the fatty acid or mixed fatty acids are theoretically required to react with the neomycin. However, an excess of the fatty acid is preferred to obtain optimum yields. Methods by which the neomycin salts can be prepared are well known.

Illustrative of suitable neomycin salts of higher fatty acids suitable for use in the present invention are neomycin palmitate, neomycin stearate, neomycin laurate, neomycin myristate, neomycin salt of coconut oil fatty acids and neomycin salt of tallow fatty acids. The preferred neomycin salt is neomycin palmitate.

The neomycin fatty acid salt can be provided for the polyfilamentous suture material by simply contacting the suture substrate with a solution of the waterinsoluble neomycin salt in a solvent, such as an organic solvent which is a solvent for the neomycin but not a solvent for the suture itself. In this manner, the solvent plus the neomycin salt will cover the suture and penetrate into the interstices thereof. The solvent can then be removed by evaporation, extraction, etc. and the salt will coat and remain incorporated uniformly throughout and over the entire body of the polyfilamentous strand. This solvent coating and impregnation procedure offers the advantage moreover of enabling precise determination of the neomycin present in the suture.In the preferred impregnation method, the suture is passed through the solution of neomycin salt under slight tension at a rate slow enough to ensure saturation of the suture.

An altemative method of introducing the neomycin fatty acid salt into the suture comprises depositing the salt in situ by sequentially treating the suture with a solution of the fatty acid reactant followed by a solution of the neomycin reactant. If desired in either of the above impregnating procedures, the solutions may include a swelling agent which enhances impregnation into the suture. The swelling agent may be water or an organic solvent and the solutions can be heated if desired to aid the impregnation, provided that the neomycin fatty acid salts are not substantially destroyed by such heat.

The concentration of neomycin fatty acid salt in the surgical suture will vary depending upon the intended use and the particular microorganism against which therapeutic and prophylactic protection is desired. In all instances, however, the neomycin fatty acid salt should be present in effective concentrations, that is, concentrations sufficient to reduce the count of bacteria that may be present in a wound, preferably to a bacteria count of zero so as to completely clear the area of infection. A suture with this concentration of neomycin fatty acid salt not only exhibits a striking therapeutic effect where there is infection but eliminates the potentiation of an existing infection normally observed when a suture is present.

This effect is ordinarily obtained by utilizing a concentration of neomycin fatty acid salt of at least 3 mgs/yd of suture up to 30 or more mgs/yd of suture. The preferred concentrations of the neomycin salt are 7 to 11 mgs/yd of suture.

When the combination of neomycin fatty acid salt and wax is provided, the concentration of wax in the neomycin salt-containing suture will be equal to or less than that present in standard surgical silk sutures of similar size and sufficient to approximate the knotting characteristics of standard surgical silk. In addition, the wax eliminates the brittleness imparted the suture by the neomycin salt. Standard silk sutures contain from 4% to 5% of wax depending upon their size.

The desired concentration of wax in the sutures can be obtained by simply immersing the neomycin fatty acid salt-containing suture in a 15% solution (weight by volume) of the wax for about .07 to 0.1 second. The wax treatment is conveniently carried out in a continuous manner by passing the biocide-containing suture through the wax solution at a rate of 30 to 42 inches per second. The wax solutions are prepared by solubilizing the wax in a suitable solvent such as organic solvent. Preferred organic solvents for the wax are alkanols and especially preferred is n-propyl alcohol. Advantageously, the waxing operation is effected while maintaining the wax solution at the lowest possible temperature, that is, just sufficient to maintain the wax in solution and using the shortest possible time to provide the suture with the desired concentration of wax.The reason for the low temperature and the rapid passage of the suture through the wax solution is to preclude the possibility of leaching out of the neomycin fatty acid salt from the suture, since the solvent for the wax is ordinarily also a solvent for the neomycin fatty acid salt. The particular temperature at which the wax containing solution is maintained will vary of course depending upon the particular wax or mixture of waxes utilized but will ordinarily fall in the range of about 140"F to 1800F.

Suitable waxes which can be used include animal waxes such as spermacetic and degras, insect waxes such as beeswax, vegetable waxes such as carnauba, petroleum waxes such as paraffin wax and microcrystalline wax and synthetic waxes such as "Carbowax" (R.T.M.).

After the waxing step, the neomycin fatty acid salt/wax impregnated suture is dried and, in the case of synthetic sutures such as Dacron sutures, is ready for sterilization and packaging. In the case of silk sutures, the neomycin fatty acid salt/wax impregnated suture is then hot-stretched to the desired size on a silk hotstretching machine using the conventional silk method.

The polyfilamentous sutures impregnated in accordance with the present invention are of conventional configuration and materials. The sutures may be natural or synthetic sutures including for instance silk and polythene terephthalate sutures. The sutures are preferably dyed before being subjected to the neomycin salt and wax treatments using any of the conventional dyeing methods and techniques. The preferred dyeing methods are the well-known pressure dyeing techniques of the art, wherein the dye under pressure is passed through windings of the strands about perforated hollow dyeing elements. Generally the perforated dyeing elements are in the form of a hollow tube or cone and can be of metal such as aluminum, stainless steel, etc., or synthetic polymeric plastics.

Dyes suitable for the sutures of the invention have been determined and are well recognized in the suture dyeing art. It is intended that the dyes contemplated by the present invention embrace the following FDA (Food and Drug Administration of the United States of America) approved dyes for the indicated materials: Silk Logwood Dacron D & C Green No.6 Nylon Logwood and D.C. Green No. 5 Cotton D. C. Green No. 9 Polypropylene [phthalocyaninato(2- 1)] copper In order to obtain dyed polyfilamentous sutures containing neomycin salt, wax and dye of uniform concentration, it is important to select a dye which exhibits relative insolvency in the solvents used to solubilize the neomycin salt and wax when incorporated. Alternatively, a solvent is selected for impregnants which do not possess strong solvency action toward the dye employed.Also contemplated is the dyeing of the sutures simultaneously with the neomycin salt and wax treatments, which operation would of course avoid any leaching of the impregnants.

In order that the invention may readily be carried into practice, a number of embodiments will now be described in detail, by way of example: EXAMPLE 1 250 yards of surgical silk sutures which have been dyed with Logwood and treated with aluminum acetate in the conventional manner are measured out and oven dried for three hours at 2000F.

A 15% solution (weight by volume) of neomycin palmitate in n-propyl alcohol is prepared by mixing the solvent and salt heating the mixture at a temperature of 100" to 1100F to bring the neomycin palmitate into solution. The solution is poured into a long narrow trough one inch by one inch eight feet and the sutures are passed slowly through the solution under slight tension (i.e., 0--20 grams) to ensure maximum pickup. The temperature of the solution while in the tube is maintained at approximately 900 F and the time in the eight foot trough is about 5(w72 seconds for this size suture.

After the treatment with the neomycin palmitate, the suture is passed directly from the solution through a heated vertical tower travelling 18 feet up before touching the first guide and then down to a take-up spool running at the slowest possible speed to allow drying time. The impregnated silk suture is then hotstretched to size (2/0) on a silk hot-stretch machine using the regular silk method.

EXAMPLE 2 250 yards of suture size specification 2/0 braided surgical Dacron sutures which have been dyed, hot-stretched and softened, are measured out and oven dried for three hours at 2000F. A 40% solution (w/v) of neomycin palmitate powder in n-propyl alcohol is prepared and a suture is impregnated with the neomycin palmitate employing the general procedure described in Example 1, except that the neomycin palmitate impregnated braided Dacron suture is not hot-stretched after the impregnation as it is with silk sutures.

EXAMPLE 3 Dacron and silk sutures impregnated with both neomycin palmitate and wax are prepared as follows: The sutures first are treated with neomycin palmitate employing the general procedures outlined in Examples I and 2 above. After drying of the neomycin palmitate treated sutures the sutures are then waxed in the following manner: A wax solution composed of a mixture of beeswax and paraffin wax is dissolved in butyl acetate as a solvent. For each pound of wax mixture, ten ounces of beeswax and six ounces of paraffin wax in six quarts of butyl acetate is employed.

The neomycin-palmitate-impregnated suture is passed through the wax solution at a temperature of about 1500F using a three inch cycle through the solution. The immersion time of the wax solution is approximately 0.7 to 0.1 second.

The silk sutures treated with neomycin palmitate and waxed as described above are then hot-stretched to a size on the silk hot-stretch machine using the regular silk method. It is not necessary to hot-stretch the Dacron suture after the waxing step since the Dacron suture has already been hot-stretched to size preliminary to the neomycin palmitate treatment.

The silk and Dacron sutures thus prepared and the specific conditions of the treatments are reported in Table 1 below: TABLE 1 Neomycin-Wax Treatment Silk % Solution % of Hot of Neomycin * Time in Mix of Stretch Size Palmitate 8' Trough Wax ** After Wax Seconds 7-0 50% 8068 2 lb. 3% 4-0 1 5 /n 850 2 lib. 9% 2-0 15% 72-50 1 lib. 14% 2 5.5% 9290 1+lib. 14% 5 3.5% 9240 1+ lib. 15% Dacron % Solution /n of Hot of Neomycin * Time in Mix of Stretch Size Palmitate 8' Trough Wax ** After Wax 7-0 50% 8068 2 lb. 0 4-0 60 9059 2 lb. 0 2-0 60% 9050 1+lb. 0 2 40 /n 77--40 1+ lib. 0 * Material kept in trough for maximum length of time for maximum pick up of neomycin palmitate. This will be kept in solution for a minimum of 40 seconds but will vary up to 90 seconds depending on size of take up spool.

**Wax=each I lb. Mix comprised of 10 oz. Beeswax and 6 oz. Paraffin Wax.

6 quarts of Butyl Acetate.

EXAMPLE 4 The 2/0 neomycin/wax-containing silk and Dacron sutures prepared as described in Example 3 are compared to untreated suture in tissue of mlce contaminated with Staphylococcus auereus. Except for the size of suture the testing procedure followed is that described in "Physical and Chemical Configuration of Sutures in the Development of Surgical Infection", Edlich, R. F., Panek, P. H., Rodeheaver. G. T., Kurtz, L. D., Edgerton, M. T., Annals of Surgery Volume 177, pages 679-688, 1973.

On the fourth post-operative day, the sutures and needle tract were examined for evidence of infection by excising a block of infected tissue and quatitatively analyzing the tissue for viable bacteria. The results of the tests are summarized below in Table II.

TABLE II Viable Inoculum* Bacteria after Suture (No. of bacteria) 4 Days 2/0 silk 103 102 2/0 silk 105 104 2/0 silk 108 108 None (Needle tract) 105 0 (Needle tract) 106 103 2/0 silk treated with neomycin salt/wax 108.5 0 2/0 Dacron 105 105 2/0 Dacron 108 106 None (Needle tract) 105 0 (Needle tract) 108 103 2/0 Dacron treated with neomycin salt/wax 108.8 0 *Staphylococcus aureas The data confirm that the presence of a silk or Dacron suture potentiates the growth of bacteria in the wound if bacteria is present.The data also shows that the neomycin palmitate treated sutures of the invention reduced the viable bacteria to 0 in 4 days thus demonstrating the therapeutic effects of the biocidal sutures of the invention.

The sutures of the invention exhibit the same excellent results against the bacteria Proteus mirabilis, E. coli. and Pseudomonas aerugenosa. With the latter bacteria, however, a concentration of neomycin palmitate on the order of mg/yd is inadequate and it is necessary to increase the concentration of neomycin palmitate to 7-8 mg/yd in order to achieve a therapeutic effect.

The following example is included to demonstrate the improved knot retention characteristics exhibited by surgical sutures containing both the neomycin fatty acid salt and wax.

EXAMPLE 5 2/0 standard surgical silk is treated with neomycin palmitate using the procedure of Example 3 to provide a surgical suture containing 3.5 mg/yd neomycin. A silk suture containing 3.5 mg/yd neomycin palmitate and wax (10/6 beeswax/paraffin wax) is also prepared as described in Example 3. A plurability of square knots were tied in the sutures thus prepared, each knot comprised of three or four "throws" one over the other having the ear lengths indicated in the table below. Each knot is then tested by grasping the suture on either side of the knot and pulling to see if the knot "slipped". The ratio of the number of knots slipped:the total number of knots is recorded and the results are summarized in the table below.

Dacron sutures were similarly treated to provide the sutures containing 3.7 mg/yd neomycin palmitate and Dacron sutures containing 3.7 mg/yd neomycin palmitate and wax (10/6 beeswax paraffin) as described in Example 3. The Dacron sutures thus prepared are tested for their knot retention characteristics and these results also are reported in the Table III below.

TABLE III Knot Retention Characteristics of Treated Silk Suture Number of Knots Slipped: Total Number of Knots Neomycin Neomycin Ear Surgical Palmitate Palmitate Throws Length Silk Silk Wax Silk 3 0.2 1:5 2:5 1:5 3 0.3 0:5 2:5 1:5 3 0.4 0:5 2:5 0:5 3 0.6 0:5 0:5 0:5 Knot Retention Characteristics of Treated Dacron Sutures Number of Knots Slipped: Total Number of Knots Neomycin Neomycin Ear Surgical Palmitate Palmitate Throws Length Dacron Dacron Wax Dacron 3 0.3 0:5 5:5 4:5 3 0.4 0:5 5:5 2:5 4 0.1 0:5 5:5 2:5 4 0.2 0:5 5:5 0:5 4 0.3 0:5 1:5 0:5 4 0.4 0:5 0:5 0:5 The data demonstrates that the addition of neomycin palmitate to standard silk and Dacron sutures has a tendency to affect the sutures with a slipperiness such that the knot retention characteristics are adversely affected.As established by the data this tendency for knots to slip is greatly reduced with sutures containing both neomycin palmitate and wax.

WHAT WE CLAIM IS: 1. A surgical suture having a therapeutic and prophylactic effect against bacterial infections, which comprises a soft, pliable polyfilamentous surgical suture having incorporated uniformly throughout and onto the body thereof an amount of a neomycin salt of at least one fatty acid containing from 12 to 18 carbon atoms.

2. A surgical suture according to Claim 1, wherein the neomycin fatty acid salt is neomycin palmitate.

3. A surgical suture according to Claim 2, wherein the neomycin palmitate is present at a concentrate of at least 3 mg/yd of the suture.

4. A surgical suture according to Claim 1, wherein the suture is a silk suture.

5. A surgical suture according to Claim 1, wherein the suture is a polyethylene terephthalate suture.

6. A surgical suture according to Claim 1, including dispersed uniformly throughout the body of said neomycin - fatty - acid - salt - containing suture, a wax in a concentration equal to or less than that present in a standard surgical silk of similar size.

7. A surgical suture according to Claim 6, wherein the wax is a mixture of beeswax and paraffin wax.

8. A surgical suture according to Claim 6, wherein the neomycin fatty acid salt is neomycin palmitate.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

TABLE III Knot Retention Characteristics of Treated Silk Suture Number of Knots Slipped: Total Number of Knots Neomycin Neomycin Ear Surgical Palmitate Palmitate Throws Length Silk Silk Wax Silk

3 0.2 1:5 2:5 1:5

3 0.3 0:5 2:5 1:5

3 0.4 0:5 2:5 0:5

3 0.6 0:5 0:5 0:5 Knot Retention Characteristics of Treated Dacron Sutures Number of Knots Slipped: Total Number of Knots Neomycin Neomycin Ear Surgical Palmitate Palmitate Throws Length Dacron Dacron Wax Dacron

3 0.3 0:5 5:5 4:5

3 0.4 0:5 5:5 2:5

4 0.1 0:5 5:5 2:5

4 0.2 0:5 5:5 0:5

4 0.3 0:5 1:5 0:5

4 0.4 0:5 0:5 0:5 The data demonstrates that the addition of neomycin palmitate to standard silk and Dacron sutures has a tendency to affect the sutures with a slipperiness such that the knot retention characteristics are adversely affected.As established by the data this tendency for knots to slip is greatly reduced with sutures containing both neomycin palmitate and wax.

WHAT WE CLAIM IS: 1. A surgical suture having a therapeutic and prophylactic effect against bacterial infections, which comprises a soft, pliable polyfilamentous surgical suture having incorporated uniformly throughout and onto the body thereof an amount of a neomycin salt of at least one fatty acid containing from 12 to 18 carbon atoms.
2. A surgical suture according to Claim 1, wherein the neomycin fatty acid salt is neomycin palmitate.
3. A surgical suture according to Claim 2, wherein the neomycin palmitate is present at a concentrate of at least 3 mg/yd of the suture.
4. A surgical suture according to Claim 1, wherein the suture is a silk suture.
5. A surgical suture according to Claim 1, wherein the suture is a polyethylene terephthalate suture.
6. A surgical suture according to Claim 1, including dispersed uniformly throughout the body of said neomycin - fatty - acid - salt - containing suture, a wax in a concentration equal to or less than that present in a standard surgical silk of similar size.
7. A surgical suture according to Claim 6, wherein the wax is a mixture of beeswax and paraffin wax.
8. A surgical suture according to Claim 6, wherein the neomycin fatty acid salt is neomycin palmitate.
9. A surgical suture according to Claim 6, wherein the suture is a silk suture.
10. A surgical suture according to Claim 6, wherein the suture is a polyethylene terephthalate suture.

1I. A surgical suture according to Claim 1, treated substantially as described herein with reference to any one of Examples 1 to 3 herein.