US20070141245A1 - System and method for coating filaments - Google Patents

Abstract

System and method for coating a suture line are disclosed. The system includes a first guide positioned to orient the suture line for entry into a coating tube. The system also includes a coating tube having an inlet opening to admit the suture line and an outlet opening through which the suture line exits the coating tube. The coating tube includes a fill opening through which a coating composition is introduced into the coating tube to a level sufficient to submerge a portion of the suture line. The system further includes a second guide positioned to orient the suture line exiting from the dryer.

Description

CROSS-REFERENCE TO RELATED APPLICATION
• The present application claims the benefit of and priority to U.S. Provisional Application Ser. No. 60/752,685 filed on Dec. 20, 2005, the entire disclosure of which is incorporated by reference herein.
BACKGROUND
• 1. Technical Field
• The present disclosure relates generally to filament coating systems and methods, more specifically to systems and methods for coating sutures.
• 2. Background of Related Art
• Surgical sutures are primarily used during surgery to stitch together sections of tissue to aid in post-surgical healing. Sutures are often coated with various substances to improve their knot tie-down characteristics. In addition, coating increases suture's surface lubricity which reduces the friction associated with passing of the suture through the tissue, thereby reducing tissue trauma. Conventionally, suture coatings have been applied by dipping, bushing, wiping, spraying or drip coating. Dip coating involves submergence of a suture line into a coating composition contained in a vessel. Typically, dip coating involves the use of multiple guiding means (e.g., rollers) to pass the suture through the coating composition. For instance, a horizontally passing suture needs to be directed downward into and upward out of the vessel containing the coating composition. Thus, at least one of the guiding roller(s) is positioned within the coating vessel, in contact with the suture before the line is dried. This contact by the roller frequently removes coating material from the suture, thereby reducing the effectiveness of the coating.
• Coating has also been accomplished using filling heads. This method involves passing a suture line through a V-shaped notch. Coating composition injected into the notch contacts and coats the suture line. The suture line does not come in contact with guiding rollers until after the coating dries. Although the coating system using filling heads provides more consistent coating for the suture line, the contact time for coating solution to penetrate into suture is significantly less (e.g., less that 0.1 second) than that provided by the conventional dipping coating mechanisms.
• Therefore, there is a need for a coating system which allows for more consistent coating at high contact time.
SUMMARY
• A system and method for coating a suture line are disclosed. The system includes an elongated coating tube having coater heads disposed at both ends thereof. The suture line is fed into the coating tube through an opening in one of the coater heads and exits the coating tube through an opening in the other coater head. Guide rollers that contact the un-coated suture ensure alignment of the suture line as it enters the coating tube. The coating tube is filled with a coating composition to a level above the entry point of the suture line. The composition pours through the openings of the coating tube and is collected by the coater heads so that it is circulated during the coating process to ensure proper ratio of coating agent to solvent. After exiting the coating tube, the suture line passes through a dryer and then is guided by a set of rollers to a winding roll. Then, the suture contacts guide rollers only after exiting the dryer, thereby helping to ensure a uniform coating.
• According to one embodiment of the present disclosure, a system for coating a suture line is disclosed. The system includes a first guide positioned to orient the suture line for entry into a coating tube. The system also includes a coating tube having an inlet opening to admit the suture line and an outlet opening through which the suture line exits the coating tube. The coating tube includes a fill opening through which a coating composition is introduced into the coating tube to a level sufficient to submerge a portion of the suture line. The system further includes a second guide positioned to orient the suture line exiting from the dryer.
• According to another embodiment of the present disclosure, a method for coating at least one suture line is disclosed. The method includes the step of orienting the suture line through a first guide for entry into a coating tube. The coating tube includes an inlet opening to admit the suture line and an outlet opening through which the suture line exits the coating tube. The coating tube further includes one or more fill openings through which a coating composition is introduced into the coating tube a level sufficient to submerge a portion of the suture line. The method also includes the steps of submerging the suture line in the coating composition filling the coating tube as well as orienting the suture line exiting from the dryer through a second guide.
• According to a further embodiment of the present disclosure, a system for coating at least one suture line is disclosed. The system includes a first guide positioned to orient the suture line for entry into a coating tube having an inlet opening to admit the suture line passing through the first guide and an outlet opening through which the suture line exits the coating tube. The coating tube also includes at least one fill opening through which a coating composition is introduced into the coating tube to at least a level sufficient to submerge at least one portion of the suture line, such that the coating composition flows out through at least one of the inlet and outlet openings. The system also includes at least one coater head disposed at each of end of the coating tube, the first and second coater head configured to collect the coating composition flowing through the inlet and outlet openings and a second guide positioned to orient the suture line exiting the coating tube.
BRIEF DESCRIPTION OF THE DRAWINGS
• The above and other aspects, features, and advantages of the present disclosure will become more apparent in light of the following detailed description when taken in conjunction with the accompanying drawings in which:
• FIG. 1 is a schematic diagram of a dip suture coating system according to one embodiment of the present disclosure;
• FIG. 2 is a schematic diagram of a dip coater according to the present disclosure;
• FIG. 3 is a schematic diagram of a distal coater head useful in embodiments of coating systems according to the present disclosure;
• FIG. 4 is a sectional view of a dip coating tube according to the present disclosure; and
• FIG. 5 is a flow diagram of a method for coating a suture line according to the present disclosure.
DETAILED DESCRIPTION
• Preferred embodiments of the present disclosure will be described herein below with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail.
• The present disclosure provides for a horizontal dip coating system. The system includes one or more input winders inputting a suture line into a dip coater using a first set of one or more guiding rollers. The dip coater includes a coating tube positioned horizontally with a coater head disposed at proximal and distal ends thereof. The coating tube and the coater heads include openings through its centers to allow for the suture line to pass horizontally therethrough. A coating composition fills the coating tube above the openings of the coating tube through which the suture line passes to coat the line. Any coating composition that leaks out of the coating tube is collected by the coater heads. The coating composition is injected at a higher rate than it leaks out to maintain the composition level therein. In addition, the coating composition collected by the coater heads is circulated throughout the dip coater. In some embodiments, where the coating composition includes solvent carrier and coating agent, solvent content of the coating composition is-monitored and adjusted to ensure that a predetermined ratio of coating agent to solvent is maintained. Upon coating, the suture line is dried and thereafter the line is guided by a second set of one or more rollers to winding rolls.
• FIG. 1 shows a horizontal dip coating system1 according to the present disclosure for coating a plurality of suture lines simultaneously. The coating system1 includes at least one input winder2 for passing at least onesuture line10 through adip coater3, anair wiper5, adryer6, and anair cooler7. Thereafter theline10 is wound by at least one take-up winder8, which may be part of a pull-overloading station9. It is envisioned that the pull-over loading station pulls theline10 through the coating system1. As theline10 passes through thedip coater3 it is submerged in a coating composition in order to absorb coating materials. As will be appreciated by those skilled in the art, the coating system shown inFIG. 1 includes multiple input winders and multiple take-up winders. Also, it is contemplated that each input winder and/or take-up winder may handle one or more than one suture lines (e.g., inFIG. 1 each winder handles two suture lines).
• The input winder(s)2 disperses theline10 which may be a monofilament or a multifilament braided suture. Prior to dispersing, theline10 may be prepared for coating which may involve calendaring theline10 to facilitate penetration of the coating composition into the interstices of the braid suture, especially where the present system is used to apply a second or third composition to the suture line. An example of a calendaring apparatus and method thereof is disclosed by commonly owned U.S. Pat. No. 5,312,642 entitled “Method and Apparatus for Calendering and Coating/Filling Sutures” which is hereby incorporated by reference in its entirety herein.
• The system1 also includes theair wiper5 and theair cooler7. Theair wiper5 is positioned between thedip coater3 and thedryer6 and is configured to blow gas (e.g., air, nitrogen, etc.) on the passingline10 to blow off excess composition. Theair cooler7 is positioned between thedryer6 and the take-up winder8 and is configured to blow cool air on theline10 to provide cooling for the dried line.
• FIG. 2 shows in more detail adip coater3 and thedryer6 in accordance with an embodiment of the present disclosure. Theline10 is passed through thedip coater3 so that it is immersed in a coating composition. Theline10 is guided into thedip coater3 around a first set of rollers13 (e.g.,rollers12 and14) and passed horizontally through acoating tube24 which is filled with acoating composition31 containing the dissolved coating agent. It is envisioned that thedip coater3 may be configured to coat a plurality oflines10. For example, thedip coater3 may have a plurality ofcoating tubes24 corresponding to the number oflines10. Alternatively, the coating tube4 may be substituted by a container configured to coatmultiple lines10.
• As theline10 is passed horizontally through thecoating tube24, coating composition is applied to theline10. Thecoating tube24 is positioned horizontally and may have a cylindrical shape and may be approximately 1′ to 10′ in length. Typically, the coating tube is 3′ to 5′ long. In addition, thecoating tube24 is preferably manufactured from stainless steel material that does not react with the coating composition. For example, the coating tube may be glass or glass-lined. In addition, if a metal tube is used, it may be desirable to passivate the tube to reduce its reactivity. Passivation methods and materials are within the purview of those skilled in the art. The outer diameter of tube can vary depending on a number of factors such as the number of filaments being treated, the particular coating composition being applied and the desired contact time between the composition and the suture line. Those skilled in the art will appreciate that the cylindrical shape is merely only one embodiment of thecoating tube24 and that it may have a variety of shapes (e.g., rectangular, triangular, or hexagonal cross-sectional shapes, etc.).
• Theline10 enters thecoating tube24 through aproximal coater head18 which is discussed in more detail below with reference to adistal coater head20, both of which have a circular cross section. It is envisioned that theline10 passes throughdip coater3 through anopening91 of theproximal coater head18, anopening92 of thecoating tube24, anopening93 of thecoating tube24 and anopening94 of thedistal coater head20. Theopenings91,92,93,94 are preferably drilled through the center ofsurfaces95,96,97,98 respectively, of ceramic eyelets disposed within the proximal and distal coater heads18,20 and thecoating tube24 as shown inFIG. 3 and discussed in more detail below. The openings may be drilled in a plurality of ways (e.g., a laser) to achieve a straight path for theline10 through thedip coater3.
• Thecoating tube24 is filled with acoating composition31 through asupply tube56 which is connected thereto viaadapter60 having a male national pipe thread (MNPT) or another type of connecting means. Theadapter60 may be coupled to thecoating tube24 at an angle (e.g., a 135° angle) with the longitudinal axis of thecoating tube24 at the top portion thereof. Those skilled in the art will appreciate that the tubing used to interconnect the components of the dip coater3 (e.g., thesupply tube56 and other tubing discussed below) may be manufactured from any materials allowing the tubing to be flexible as well as chemically inert to a variety of organic solvents. In one embodiment, thesupply tube56 is made from PTFE and has a ⅜″ diameter. Thecoating composition31 is carried into thecoating tube24 via a circulatingpump34 which withdraws thecomposition31 from atank28 through atube58. Thetank28 preferably includes a stirring device, such as amagnetic stirrer driver26 positioned thereunder, to prevent settling or other separation of the components of the coating composition.
• FIG. 3 shows a cross sectional view of thedistal coater head20 along the vertical axis of thecoating tube24. Thecoating tube24 is filled with thecomposition31 to a level which is at least above the line10 (e.g., above the center of the coating tube24) to ensure that theline10 is immersed in thecomposition31 as theline10 passes through thecoating tube24. Since thecomposition31 fills thecoating tube24 above theopening93,composition31 may leak therethrough and be collected in the proximal and distal coater heads18,20. As a result ofcomposition31 leaking out of thecoating tube24, the in-flow must equal or exceed out-flow. Therefore, thecomposition31 will be circulated (e.g., continually supplied into the coating tube24) to maintain a steady state, where the level of thecomposition31 is continuously above theopenings92,93.
• Theassembly20 includes a removable reducingtee80 configured to drain leakingcomposition31. The reducingtee80 can advantageously have an outer diameter larger than the outer diameter of thecoating tube24 so that thetee80 fits over thecoating tube24. Thereturn adapter22 is the reducing portion of the reducingtee80 and preferably includes an MNPT connection.
• Theremovable tee80 is connected to thecoating tube24. Thedistal coater head20 includes twoceramic eyelets72,74. Theceramic eyelet72 is positioned at the distal end of thecoating tube24 within the reducingtee80 and theceramic eyelet74 is attached at the distal end of the reducingtee80. Theceramic eyelets72,74 are designed to optimize alignment of theopenings93,94 while minimizing the solvent lost during the coating process as discussed in more detail below. Those skilled in the art will appreciate that theproximal coater head18 includes the same components (e.g., ceramic eyelet, o-ring, etc.) assembled in the same manner as discussed above with regard to thedistal coater head20.
• With reference toFIG. 2, thecomposition31 out-flows throughreturn adapters21,22 coupled to the bottom portion of the proximal and distal coater heads18,20 respectively and returntubes45,42 to areturn tank32. In addition, thereturn tank32 collects anyexcess composition31 present in thecoating tube24 through anoverflow adapter40 which is coupled to the upper portion thereof. Upon reaching theoverflow adapter40, theexcess coating composition31 flows through areturn tube44 to thereturn tank32 and mixes withreturn composition33. The outlet ofoverflow adapter40 is also used to determine when thecomposition31 filled thecoating tube24 to the desired level. Theoverflow adapter40 is positioned above theopenings91,92,93,94 hence whencomposition31 reaches theoverflow adapter40 and flows therethrough and into thereturn tank32. This ensures that thesuture line10 is submerged inside thecoating tube24. There can bemultiple overflow adapters40 positioned along thecoating tube24 for higher recirculation rate.
• FIG. 4 shows a cross sectional view along the section line4 of thecoating tube24.Adapter60 andadapter54 are shown positioned on the upper portion of thecoating tube24 while thedrain valve46 is positioned on the bottom portion thereof. In addition, theoverflow adapter40 is positioned on the upper portion of thecoating tube24 as well, slightly below theadapters54,60. Thedrain valve46 may be used toempty coating tube24 of thecoating composition31 upon shut down of the coating system1 for maintenance or once the coating process is finished.
• It is also envisioned that thereturn composition33 may be recycled during the coating process. Typically, a portion of any volatile solvent in the coating composition may evaporate during the coating process beforeexcess composition31 flows to thereturn tank32. Thereturn composition33 is contained within the coating system1 by a plurality of tubes and adapters discussed above to contain thereturn composition33 and to minimize solvent loss and vapor escape. Some vapor which does escape is vented through vent headers (not shown) installed above thecoating tube24.
• In order for thereturn composition33 to be recycled, it must be verified that the desired coating agent composition is maintained. With reference toFIG. 2, acontroller48 can be connected to thereturn tank32 and configured to test the density and/or viscosity of thereturn composition33 using, e.g., a mass flow meter. If the density/viscosity of thereturn composition33 exceeds a predetermined level (e.g., density of the original composition31) then thecontroller48 signals that the composition needs to be adjusted e.g., by injecting additionalsolvent carrier35 directly into thecoating tube24 or into thereturn tank32.
• In one embodiment, thecontroller48 is electrically connected to a solvent pump96 (e.g., solvent supply means) which injects solvent35 into thecoating tube24 and a control valve50 adjusts the flow of the solvent35 into thereturn tank32. The solvent35 can be injected into thecoating tube24 through thesolvent adapter54 connected to thesolvent tank36 through atube52. Thesolvent adapter54 is positioned at an angle (e.g., a 45° angle) with the longitudinal axis of thecoating tube24 at the top portion thereof while thedrain valve46 is positioned on the bottom portion thereof. In addition, thereturn tank32 includes a magnetic stirrer driver30 to maintain uniformity of the coating composition throughout thereturn composition33 and to mix any added solvent35. Furthermore,return tank32 supplies thereturn composition33 totank28 where it is recycled and continually pumped into thecoating tube24.
• FIG. 5 shows a method for coating thesuture line10 using the coating system1 of the present disclosure. Instep150 thecoating tube24 is filled with thecomposition31 above theopenings92,93 to ensure that as theline10 is submerged in thecomposition31. Thecomposition31 is continually fed into thecoating tube24 at a rate which is equal to or slightly exceeds the rate at which thecomposition31 leaks through theopenings92,93. This allows the level of thecomposition31 to stay above theopenings92,93 despite the loss of thecomposition31. Thus, only the level of thecomposition31 must be controlled during the coating process, whereas, conventional coating techniques, which depend on point coating, require precise control of the flow rate of the coating composition.
• Instep152,excess composition31 is collected. This is accomplished by collecting thecomposition31 from the proximal and distal coater heads18,20 which are configured to catch excess liquid and from theoverflow adapter40 which prevents overfilling of thecoating tube24 by providing a flow path for anyexcess composition31. Theexcess composition31 flows to thereturn tank32.
• Since the coating system1 relies on constant supply of thecomposition31 to thecoating tube24 thecomposition31 must be circulated. As discussed above, in some embodiments the coating process involves application of coating agent dissolved in a volatile organic solvent. Therefore, solvent may need to be replenished to maintain the desired coating agent levels within thecomposition31. Instep154, thecontroller48 analyzes the density/viscosity ofreturn composition33 to determine whether additional solvent35 needs to be added. If the density is above the desired limit (e.g., the coating agent to solvent ratio within thereturn composition33 is larger than that ratio within the composition31) then instep156, thecontroller48 adjusts the solvent content. Adjustment of solvent level can be accomplished by signaling thesolvent pump96 which injects the solvent35 into thecoating tube24 and/or opening the control valve50 to add solvent35 into thereturn composition33. Thereturn composition33 is then added intotank28 from where it is continuously injected intocoating tube24.
• Each portion of thesuture line10 should reside within thecoating tube24 approximately between 0.5 second to 10 minutes, preferably the residence time is about 1 minute. As theline10 thedip coater3 theline10 enters thedryer6 and instep158, theline10 is dried. The drying temperature depends on the coating composition used and may range approximately between the ambient room temperature (e.g., 25° C.) at the low extreme and above 100° C. at the upper extreme. It is also envisioned that thedryer6 uses heated gas (e.g., air, nitrogen, etc.) to dry theline10. Instep160, theline10 is cooled by theair cooler7, which blows cool air onto the driedline10 and thereafter theline10 is guided by a second set of rollers39 (e.g., a roller38) into the winder8 where it is wound.
• The present disclosure allows theline10 to avoid physical contact with various machine parts during the coating process (e.g., guiding rollers). Theline10 comes in contact only with the coating composition between the time it is fed into thedip coater3 and the time it is wound on the winder8. This is due to the horizontal positioning of thecoating tube24 and the horizontal orientation of theline10 therethrough, which allows theline10 to avoid physical contact with components by using a minimal amount of guiding mechanisms (e.g., guidingrollers13,39)
• Any coating composition known to be useful for coating medical devices may be applied to a medical device using the present methods and apparatus. The coating composition can be a solution, dispersion, emulsion containing, for example, one or more polymeric materials and/or one or more bioactive agents.
• In some embodiments, the coating composition includes a polymer, or a combination of polymers. The polymer is most suitably biocompatible, including polymers that are non-toxic, non-inflammatory, chemically inert, and substantially non-immunogenic in the applied amounts. The polymer may be either bioabsorbable or biostable. A bioabsorbable polymer breaks down in the body. Bioabsorbable polymers are gradually absorbed or eliminated by the body by hydrolysis, metabolic process, bulk, or surface erosion. Examples of bioabsorbable materials include but are not limited to polycaprolactone (PCL), poly-D, L-lactic acid (DL-PLA), poly-L-lactic acid (L-PLA), poly(lactide-co-glycolide), poly(hydroxybutyrate), poly(hydroxybutyrate-co-valerate), polydioxanone, polyorthoester, polyanhydride, poly(glycolic acid), poly(glycolic acid-cotrimethylene carbonate), polyphosphoester, polyphosphoester urethane, poly (amino acids), cyanoacrylates, poly(trimethylene carbonate), poly(iminocarbonate), copoly(ether-esters), polyalkylene oxalates, polyphosphazenes, polyiminocarbonates, and aliphatic polycarbonates. Biomolecules such as heparin, fibrin, fibrinogen, cellulose, starch, and collagen are typically also suitable. A biostable polymer does not break down in the body, and thus a biostable polymer is present in the body for a substantial amount of time after implantation. Examples of biostable polymers include PARYLENE™, PARYLAST™, polyurethane (for example, segmented polyurethanes such as BIOSPAN™), polyethylene, polyethlyene teraphthalate, ethylene vinyl acetate, silicone, polyethylene oxide, and polytetrafluoroethylene (PTFE).
• In some embodiments, the coating compositions of the present disclosure may also include a fatty acid component that contains a fatty acid or a fatty acid salt or a salt of a fatty acid ester. Suitable fatty acids may be saturated or unsaturated, and include higher fatty acids having more than about 12 carbon atoms. Suitable saturated fatty acids include, for example, stearic acid, palmitic acid, myristic acid and lauric acid. Suitable unsaturated fatty acids include oleic acid, linoleic acid, and linolenic acid. In addition, an ester of fatty acids, such as sorbitan tristearate or hydrogenated castor oil, may be used.
• Suitable fatty acid salts include the polyvalent metal ion salts of C6 and higher fatty acids, particularly those having from about 12 to 22 carbon atoms, and mixtures thereof. Fatty acid salts including the calcium, magnesium, barium, aluminum, and zinc salts of stearic, palmitic and oleic acids may be useful in some embodiments of the present disclosure. Particularly useful salts include commercial “food grade” calcium stearate which consists of a mixture of about one-third C16 and two-thirds C18 fatty acids, with small amounts of the C14 and C22 fatty acids.
• Suitable salts of fatty acid esters which may be included in the coating compositions applied in accordance with the present disclosure include calcium, magnesium, aluminum, barium, or zinc stearoyl lactylate; calcium, magnesium, aluminum, barium, or zinc palmityl lactylate; calcium, magnesium, aluminum, barium, or zinc olelyl lactylate; with calcium stearoyl-2-lactylate (such as the calcium stearoyl-2-lactylate commercially available under the tradename VERV from American Ingredients Co., Kansas City, MO.) being particularly useful. Other fatty acid ester salts which may be utilized include those selected from the group consisting of lithium stearoyl lactylate, potassium stearoyl lactylate, rubidium stearoyl lactylate, cesium stearoyl lactylate, francium stearoyl lactylate, sodium palmityl lactylate, lithium palmityl lactylate, potassium palmityl lactylate, rubidium palmityl lactylate, cesium palmityl lactylate, francium palmityl lactylate, sodium olelyl lactylate, lithium olelyl lactylate, potassium olelyl lactylate, rubidium olelyl lactylate, cesium olelyl lactylate, and francium olelyl lactylate.
• Where utilized, the amount of fatty acid component can range in an amount from about 5 percent to about 50 percent by weight of the total coating composition. Typically, the fatty acid component may be present in an amount from about 10 percent to about 20 percent by weight of the total coating compositions.
• In some embodiments, the coating composition contains one or more bioactive agents. The term “bioactive agent”, as used herein, is used in its broadest sense and includes any substance or mixture of substances that have clinical use. Consequently, bioactive agents may or may not have pharmacological activity per se, e.g., a dye. Alternatively a bioactive agent could be any agent which provides a therapeutic or prophylactic effect, a compound that affects or participates in tissue growth, cell growth, cell differentiation, a compound that may be able to invoke a biological action such as an immune response, or could play any other role in one or more biological processes.
• Examples of classes of bioactive agents which may be utilized in accordance with the present disclosure include antimicrobials, analgesics, antipyretics, anesthetics, antiepileptics, antihistamines, anti-inflammatories, cardiovascular drugs, diagnostic agents, sympathomimetics, cholinomimetics, antimuscarinics, antispasmodics, hormones, growth factors, muscle relaxants, adrenergic neuron blockers, antineoplastics, immunogenic agents, immunosuppressants, gastrointestinal drugs, diuretics, steroids, lipids, lipopolysaccharides, polysaccharides, and enzymes. It is also intended that combinations of bioactive agents may be used.
• Suitable antimicrobial agents which may be included as a bioactive agent in the bioactive coating of the present disclosure include triclosan, also known as 2,4,4′-trichloro-2′-hydroxydiphenyl ether, chlorhexidine and its salts, including chlorhexidine acetate, chlorhexidine gluconate, chlorhexidine hydrochloride, and chlorhexidine sulfate, silver and its salts, including silver acetate, silver benzoate, silver carbonate, silver citrate, silver iodate, silver iodide, silver lactate, silver laurate, silver nitrate, silver oxide, silver palmitate, silver protein, and silver sulfadiazine, polymyxin, tetracycline, aminoglycosides, such as tobramycin and gentamicin, rifampicin, bacitracin, neomycin, chloramphenicol, miconazole, quinolones such as oxolinic acid, norfloxacin, nalidixic acid, pefloxacin, enoxacin and ciprofloxacin, penicillins such as oxacillin and pipracil,nonoxynol 9, fusidic acid, cephalosporins, and combinations thereof. In addition, antimicrobial proteins and peptides such as bovine lactoferrin and lactoferricin B may be included as a bioactive agent in the bioactive coating of the present disclosure.
• Other bioactive agents which may be included as a bioactive agent in the coating composition applied in accordance with the present disclosure include: local anesthetics; non-steroidal antifertility agents; parasympathomimetic agents; psychotherapeutic agents; tranquilizers; decongestants; sedative hypnotics; steroids; sulfonamides; sympathomimetic agents; vaccines; vitamins; antimalarials; anti-migraine agents; anti-parkinson agents such as L-dopa; anti-spasmodics; anticholinergic agents (e.g. oxybutynin); antitussives; bronchodilators; cardiovascular agents such as coronary vasodilators and nitroglycerin; alkaloids; analgesics; narcotics such as codeine, dihydrocodeinone, meperidine, morphine and the like; non-narcotics such as salicylates, aspirin, acetaminophen, d-propoxyphene and the like; opioid receptor antagonists, such as naltrexone and naloxone; anti-cancer agents; anti-convulsants; anti-emetics; antihistamines; anti-inflammatory agents such as hormonal agents, hydrocortisone, prednisolone, prednisone, non-hormonal agents, allopurinol, indomethacin, phenylbutazone and the like; prostaglandins and cytotoxic drugs; estrogens; antibacterials; antibiotics; anti-fungals; anti-virals; anticoagulants; anticonvulsants; antidepressants; antihistamines; and immunological agents.
• Other examples of suitable bioactive agents which may be included in the coating composition include viruses and cells, peptides, polypeptides and proteins, analogs, muteins, and active fragments thereof, such as immunoglobulins, antibodies, cytokines (e.g. lymphokines, monokines, chemokines), blood clotting factors, hemopoietic factors, interleukins (IL-2, IL-3, IL-4, IL-6), interferons (β-IFN, (α-IFN and γ-MN), erythropoietin, nucleases, tumor necrosis factor, colony stimulating factors (e.g., GCSF, GM-CSF, MCSF), insulin, anti-tumor agents and tumor suppressors, blood proteins, gonadotropins (e.g., FSH, LH, CG, etc.), hormones and hormone analogs (e.g., growth hormone), vaccines (e.g., tumoral, bacterial and viral antigens); somatostatin; antigens; blood coagulation factors; growth factors (e.g., nerve growth factor, insulin-like growth factor); protein inhibitors, protein antagonists, and protein agonists; nucleic acids, such as antisense molecules, DNA and RNA; oligonucleotides; and ribozymes.
• A single bioactive agent may be utilized to form the coating composition or, in alternate embodiments, any combination of bioactive agents may be utilized to form the coating composition applied in accordance with the present disclosure.
• The amounts of bioabsorbable coating composition to be applied to the suture vary depending upon the specific construction of the suture, the size and the material of this construction. In general, the coating composition applied to an unfilled suture will constitute from about 1.0 to about 3.0 percent by weight of the coated suture, but the amount of coating composition on may range from as little as about 0.5 percent, by weight, to as much as 4.0 percent or higher. For a preferred filled (i.e., containing a storage stabilizing agent) braided suture, amounts of coating composition will generally vary from about 0.5% to 2.0% with as little as 0.2% to as much as 3.0%. As a practical matter and for reasons of economy and general performance, it is generally preferred to apply the minimum amount of coating composition consistent with good surface lubricity and/or knot tie-down characteristics and this level of coating add on is readily determined experimentally for any particular suture.
• The described embodiments of the present disclosure are intended to be illustrative rather than restrictive, and are not intended to represent every embodiment of the present disclosure. Various modifications and variations can be made without departing from the spirit or scope of the disclosure as set forth in the following claims both literally and in equivalents recognized in law.

Claims (19)

1. A system for coating a suture line comprising:

a coating tube;

a first guide positioned to orient the suture line for entry into the coating tube; and

a second guide positioned to orient the suture line exiting the coating tube,

wherein the coating tube possesses an inlet opening to admit the suture line passing through the first guide and an outlet opening through which the suture line exits the coating tube, and the coating tube includes at least one fill opening through which a coating composition is introduced into the coating tube to at least a level sufficient to submerge at least one portion of the suture line.

2. A system as inclaim 1, wherein the coating tube further comprises at least one coater head disposed at each end of the coating tube, and the at least one coater head is configured to collect the coating composition flowing through the inlet and outlet openings.

3. A system as inclaim 2, further comprising:

a return composition tank to collect the coating composition flowing through the inlet and outlet openings.

4. A system as inclaim 3, further comprising:

a controller to determine a ratio of at least one coating agent and at least one solvent carrier in the coating composition flowing through the inlet and outlet openings; and a solvent supply means for adding the solvent to the coating composition as a fumction of the ratio.

5. A system as inclaim 4, wherein the solvent supply means supply the solvent to the return composition tank and the coating tube.

6. A system as inclaim 1, further comprising a dryer which dries the suture line at a temperature of from about to 25° C. to about 100° C.

7. A method for coating a suture line comprising:

orienting the suture line through a first guide for entry into a coating tube, the coating tube possessing an inlet opening to admit the suture line and an outlet opening through which the suture line exits the coating tube, the coating tube also possessing at least one fill opening through which a coating composition is introduced into the coating tube to at least a level sufficient to submerge at least one portion of the suture line;

submerging the suture line in the coating composition filling the coating tube; and

orienting the suture line exiting from the coating tube through a second guide.

8. A method as inclaim 7, wherein the coating tube further includes at least one coater head disposed at each end of the coating tube and the at least one coater head is configured to collect the composition flowing through the inlet and outlet openings.

9. A method as inclaim 8, further comprising the step of:

collecting the composition flowing through the inlet and outlet openings in a return composition tank.

10. A method as inclaim 9, further comprising the step of:

determining a ratio of a coating agent and a solvent in the coating composition flowing through the inlet and outlet openings; and

adding the solvent to the coating composition as a function of the ratio.

11. A method as inclaim 10, wherein the adding the solvent step includes supplying the solvent to the return composition tank and the coating tube.

12. A method as inclaim 7, further comprising drying the suture line exiting from the coating tube at a temperature in the range of from about 25° C. to about 100° C.

13. A method as inclaim 12, ftrther comprising the steps of:

blowing a gas onto the suture line exiting the coating tube prior to drying; and

cooling the suture line prior to passing the at least one suture line through the second guide.

14. A method as inclaim 7, wherein the step of submerging the suture line includes determining the level sufficient to submerge and wet the at least one suture line.

15. A system for coating a suture line, comprising:

a coating tube possessing an inlet opening to admit the suture line into the coating tube and an outlet opening through which the suture line exits the coating tube, the coating tube possessing at least one fill opening through which a coating composition is introduced into the coating tube to at least a level sufficient to submerge at least one portion of the suture line;

a first guide positioned to orient the suture line for entry into the coating tube;

a second guide positioned to orient the suture line exiting the coating tube; and

at least one coater head disposed at each of end of the coating tube,

wherein the coating composition in the coating tube flows out through at least one of the inlet and outlet openings and the at least one coater head is configured to collect the coating composition flowing through the inlet and outlet openings.

16. A system as inclaim 15, further comprising:

a return composition tank to collect the coating composition flowing through the inlet and outlet openings.

17. A system as inclaim 16, further comprising:

a controller to determine a ratio of at least one coating agent and at least one solvent carrier in the coating composition flowing through the inlet and outlet openings; and

a solvent supply means for adding the solvent to the coating composition as a function of the ratio.

18. A system as inclaim 17, wherein the solvent supply means supply the solvent to the return composition tank and the coating tube.

19. A system as inclaim 15, further comprising a dryer which dries the suture line at a temperature in the range of from about 25° C. to about 100° C.

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