Synthetic electrosurgical lubricants, kits and related methods - Patent Application 20070122997

Abstract

Electrosurgical lubricants, sterilization kits containing the lubricants, methods for using the lubricants, and methods for manufacturing sterilization kits containing the lubricants. Electrosurgical devices utilize high-frequency electrical current to cut and coagulate tissue during surgery. A problem with electrosurgical devices is that their heat can leave tissue, such as human tissue, on the device that is generally difficult to remove even with repeated cleaning. It has been found that electrosurgical lubricants significantly reduce the amount of eschar that accumulates on electrosurgical devices, reduce the tendency of electrodes to adhere to tissue at the surgical site, and prevent damage to the surface of the electrosurgical device.

Description

[Technical Field]

[0001] The present invention relates to electrosurgical lubricants, sterile kits containing the lubricants, methods for using the lubricants, and methods for manufacturing sterile kits containing the lubricants. Electrosurgical devices utilize high-frequency electrical current to cut and coagulate tissue during surgery. A problem with electrosurgical devices is that their heat can leave tissue, including human tissue, on the device that is generally difficult to remove even with repeated cleaning. The electrosurgical lubricants of the present invention have been found to significantly reduce the amount of eschar that accumulates on electrosurgical devices, reduce the tendency of electrodes to adhere to tissue at the surgical site, and prevent damage to the surface of the electrosurgical device. [Background technology]

[0002] Electrosurgical lubricants are used in conjunction with electrosurgical equipment during surgery to prevent electrodes from adhering to tissue and causing lacerations when the electrodes are detached, leading to bleeding and damage to the surgical site.

[0003] One example of an electrosurgical lubricant is a phospholipid lubricant such as soybean lecithin. While soybean lecithin is a suitable lubricant, the lubricant of the present invention possesses all of the advantages of soybean lecithin, as well as other advantages such as a high flash point, good thermal stability, and protection of the surface of electrosurgical equipment. Furthermore, soybean lecithin reduces the ability of the electrodes of electrosurgical instruments to adhere to tissue, yet is fairly stable to radiation and is an amphiphilic compound.

[0004] U.S. Patent No. 7,217,270, issued May 15, 2007, relates to a coating used to lubricate electrocautery probes in cautery devices and prevent tissue from adhering to the probe. The coating not only lubricates other medical devices but also improves device-to-device sliding. The coating includes amphiphilic lipids, amphiphilic phospholipids, glycerol-based lipids, glycerol-based phospholipids, and / or lecithin.

[0005] U.S. Patent No. 7,317,068, issued January 8, 2008, relates to polyol polyester polymers reportedly useful in personal care formulations and products containing such formulations, used or sold as materials for application to human or animal skin, hair, nails, and / or the stratum corneum. The polyol polyester polymers comprise the reaction product of at least one polyfunctional alcohol, at least one polyfunctional carboxylic acid, and at least one monofunctional carboxylic acid, where the polyfunctional alcohol contains from about 2 to about 10 carbon atoms, the polyfunctional carboxylic acid contains from about 1 to about 36 carbon atoms, and the monofunctional carboxylic acid contains from about 4 to about 24 carbon atoms. Such polyol polyester polymers may have a dynamic viscosity of from about 200 to about 5,000 centipoise at 25°C and a hydroxyl number of from about 40 to about 300 KOH / g.

[0006] U.S. Patent No. 10,508,248, issued December 17, 2019, relates to a lubricant composition for metalworking that allegedly exhibits reduced deposit formation and evaporation compared to conventional high-temperature lubricants, resulting in improved performance in high-temperature applications. The high-temperature lubricant composition includes a base oil, the base oil including at least one polyol ester and at least one pyromellitic acid ester. In some embodiments, the lubricant composition further includes one or more additives selected from the group consisting of extreme-pressure additives, antiwear additives, rust inhibitors, corrosion inhibitors, and antioxidants, or combinations thereof. Also provided are methods for lubricating equipment using the lubricant composition, methods for improving the operational lubrication of conventional high-temperature lubricants, and methods for preparing the high-temperature lubricant composition.

[0007] U.S. Patent No. 11,198,831, issued December 14, 2021, relates to a lubricant for a medical device, comprising a first non-amphiphilic triglyceride. The lubricant further comprises a second non-amphiphilic triglyceride different from the first non-amphiphilic triglyceride. The lubricant further comprises a non-amphiphilic glycol ester.

[0008] In view of the above, there remains a need in the art for lubricants for electrosurgical devices that offer improvements over the state of the art. Summary of the Invention

[0009] The present invention relates to a synthetic lubricant composition for coating electrosurgical equipment used during surgical procedures. The lubricant reduces the amount of eschar that accumulates on electrosurgical equipment during surgery, reduces the tendency of electrodes to adhere to tissue at the surgical site, and prevents or reduces damage to the surface of the electrosurgical equipment. Other advantages include the lubricant's non-cytotoxicity, its ease of cleaning from the equipment compared to soy lecithin, its high viscosity allowing for a uniform coating of the electrosurgical equipment, and its viscosity retention even after exposure to terminal radiation. The lubricant also has excellent high-thermal stability and a high flash point of at least about 550°F (288°C). The lubricant is also protein-free, which may cause allergic reactions. Additionally, the lubricant exhibits low odor, even after aging.

[0010] In one embodiment, the electrosurgical lubricant of the present invention comprises a polymer derived from the reaction product of a) at least one monofunctional carboxylic acid, b) a polyfunctional carboxylic acid, and c) at least one polyfunctional alcohol, wherein the lubricant has a viscosity of greater than 5,000 centipoise (5 Pa·s), desirably at least 6,000 centipoise (6 Pa·s), and preferably at least about 8,000 centipoise (8 Pa·s) to about 15,000 centipoise (15 Pa·s) at 25°C, as measured according to ASTM D7042. Advantageously, the relatively high viscosity allows for substantially uniform coating of the electrosurgical device, and the cohesiveness of the lubricant composition provided, at least in part, by the high viscosity allows the lubricant to remain in contact with the device prior to use without appreciably dripping or running off the device.

[0011] In yet further embodiments, the monofunctional carboxylic acid has from about 4 to about 24 carbon atoms, the polyfunctional carboxylic acid has from 2 to about 12 carbon atoms, and the polyfunctional alcohol has from 2 to about 10 carbon atoms.

[0012] In another embodiment, the monofunctional carboxylic acid is one or more of 2-methylpropanoic acid, benzoic acid, 2-ethylbutyric acid, hexanoic acid, heptanoic acid, 2-ethylhexanoic acid, octanoic acid, nonanoic acid, 3,5,5-trimethylhexanoic acid, isononanoic acid, decanoic acid, isooctadecanoic acid, dodecanoic acid, 2-methylbutyric acid, isopentanoic acid, pentanoic acid, 2-methylpentanoic acid, 2-methylhexanoic acid, isooctanoic acid, undecylic acid, isolauric acid, isopalmitic acid, isostearic acid, and behenic acid, or derivatives thereof; and the multifunctional carboxylic acid is butanedioic acid, pentanedioic acid, hexanedioic acid, heptanedioic acid, octanedioic acid, nonanedioic acid, octan ... The polyfunctional alcohol is one or more of glycerol, pentaerythritol, dipentaerythrityl, tripentaerythritol, trimethylolpropane, neopentyl glycol, propylene glycol, 1,3-butylene glycol, 2-methyl-1,3-propanediol, dipropylene glycol, ethylene glycol, cyclohexanedimethanol, and butylethylpropanediol, or derivatives thereof.

[0013] In another embodiment, the monofunctional carboxylic acid comprises isooctodecanoic acid, the polyfunctional carboxylic acid comprises hexanedioic acid, and the polyfunctional alcohol comprises propanediol.

[0014] In further embodiments, the composition further comprises one or more of a viscosity modifier, a surfactant, an antioxidant, a pigment, a dye, a preservative, a non-stick ingredient, a fragrance, a perfuming ingredient, and an anti-inflammatory agent.

[0015] In yet a further embodiment, the viscosity ranges from 6,000 centipoise (6 Pa·s) to 12,000 centipoise (12 Pa·s) as measured according to ASTM D7042.

[0016] In a further embodiment, the viscosity ranges from 8,000 centipoise (6 Pa·s) to 11,000 (11 Pa·s) centipoise, as measured according to ASTM D7042.

[0017] Additionally, in further embodiments, the lubricant has a flash point greater than 175° C., the electrosurgical lubricant is protein-free, and the electrosurgical lubricant is sterile.

[0018] In a further embodiment, the polymer has a multimodal distribution with a first distribution peak comprising a weight average molecular weight of 25,000 to 400,000 at 5-20% of the total polymer weight, a second distribution peak comprising a weight average molecular weight of 2,000 to 40,000 at 55-60% of the total polymer weight, a third distribution peak comprising a weight average molecular weight of 500 to 7,000 at 3-18% of the total polymer weight, a fourth distribution peak comprising a weight average molecular weight of 100 to 7,000 at 9-24% of the total polymer weight, and a fifth distribution peak comprising a weight average molecular weight of 50 to 1,000 at 1-16% of the total polymer weight.

[0019] In yet a further embodiment, a method of lubricating an electrosurgical device is disclosed, the method comprising obtaining an electrosurgical device and applying a lubricant comprising the reaction product of a) at least one monofunctional carboxylic acid, b) a polyfunctional carboxylic acid, and c) at least one polyfunctional alcohol, the lubricant having a viscosity of greater than 5,000 centipoise (5 Pa·s), desirably at least 6,000 centipoise (6 Pa·s), and preferably at least about 8,000 centipoise (8 Pa·s) to about 15,000 centipoise (15 Pa·s) at 25°C, as measured in accordance with ASTM D7042. Additionally, the lubricant has a rheology that prevents "stringing" of the lubricant during application, thereby reducing contamination associated with coating the device.

[0020] In a further embodiment, a method of lubricating an electrosurgical device is disclosed that includes the steps of obtaining an electrosurgical device and applying an electrosurgical lubricant described herein to at least a portion of the electrosurgical device.

[0021] In yet a further embodiment, a kit for lubricating an electrosurgical instrument is disclosed that includes a sealed package containing an electrosurgical lubricant comprising a sealed container containing therein an electrosurgical lubricant comprising a polymer derived from the reaction product of at least one monofunctional carboxylic acid, at least one polyfunctional carboxylic acid, and at least one polyfunctional alcohol, wherein the lubricant has a viscosity of greater than 5,000 centipoise (5 Pa·s) to about 15,000 centipoise (15 Pa·s) at 25°C as measured in accordance with ASTM D7042; and an applicator that can be used to apply the electrosurgical lubricant to an electrosurgical instrument, wherein the sealed container, electrosurgical lubricant, and applicator are sterilized.

[0022] In further embodiments, the sealed container comprises a jar, bottle, tube, bag, pouch, vial, or flask, and said applicator is one or more of a sponge, wipe, brush, and cloth.

[0023] In yet a further embodiment, sterilization is achieved by exposing the sealed package to a radiation dose of 20-55 kGy.

[0024] In a further embodiment, a method of manufacturing an electrosurgical instrument lubrication kit is disclosed, the method comprising the steps of adding electrosurgical lubricant to a container, sealing the container, placing the sealed container and applicator in a package, sealing the package with the sealed container and applicator therein, and exposing the sealed package to 20-55 kGy of radiation to sterilize the sealed package, the sealed container with the electrosurgical lubricant therein, and the applicator.

[0025] In another embodiment, the sealed package is exposed to gamma or x-ray radiation.

[0026] The invention will be better understood, and other features and advantages will become apparent, from a reading of the detailed description of the invention in conjunction with the drawings, in which: [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a chart containing photographs showing test results of an eschar test on an uncoated electrosurgical blade, an electrosurgical blade coated with soy lecithin, or an electrosurgical blade coated with an electrosurgical lubricant composition of the present invention. [Figure 2] 1 is a chart containing photographs showing electrosurgical blades after electrode protection testing for a control, an electrosurgical blade coated with soy lecithin, and an electrosurgical blade coated with an electrosurgical lubricant composition of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] The present invention provides an electrosurgical lubricant having the advantages described herein. Methods of using the electrosurgical lubricant are disclosed. A sterile kit for lubricating electrosurgical instruments is also described herein, along with a method for manufacturing the kit. In a preferred embodiment, a composition comprising a bicomponent polyester polymer is used as the electrosurgical lubricant.

[0029] Electrosurgical Lubricant Complex Polyester Polymer In a preferred embodiment, the synthetic electrosurgical lubricants of the present invention relate to conjugated polyester polymers derived from the reaction of generally three types of compounds: a) one or more monofunctional carboxylic acids, b) one or more multifunctional carboxylic acids, and c) one or more multifunctional alcohols, wherein the lubricants have a viscosity of greater than 5,000 centipoise (5 Pa·s) to about 15,000 centipoise (15 Pa·s) as measured according to ASTM D7042.

[0030] Monofunctional carboxylic acid The electrosurgical lubricant comprises a conjugated polyester polymer derived from at least one monofunctional carboxylic acid. The monofunctional carboxylic acid utilized in the present invention contains a single carboxylic acid group. The monofunctional carboxylic acid may be aliphatic or aromatic. The acid may be linear or branched. The monofunctional carboxylic acid preferably contains a total of about 4 to about 24 carbon atoms.

[0031] Examples of suitable monofunctional carboxylic acids include, but are not limited to, 2-methylpropanoic acid, benzoic acid, 2-ethylbutyric acid, hexanoic acid, heptanoic acid, 2-ethylhexanoic acid, octanoic acid, nonanoic acid, 3,5,5-trimethylhexanoic acid, isononanoic acid, decanoic acid, isooctadecanoic acid, dodecanoic acid, 2-methylbutyric acid, isopentanoic acid, pentanoic acid, 2-methylpentanoic acid, 2-methylhexanoic acid, isooctanoic acid, undecylic acid, isolauric acid, isopalmitic acid, isostearic acid, and behenic acid, and derivatives and combinations thereof.

[0032] In a preferred embodiment, the monofunctional carboxylic acid comprises isooctadecanoic acid, which has the formula: [ka]

[0033] Polyfunctional Carboxylic Acid The one or more multifunctional carboxylic acids utilized to form the composite polyester polymer contain at least two carboxylic acid groups. For clarity, it is understood that the multifunctional carboxylic acid may include functional groups including functionalized dicarboxylic acids and non-functionalized dicarboxylic acids. The multifunctional carboxylic acids may be aliphatic or aromatic. They may be linear or branched. Preferred multifunctional carboxylic acids have from 2 to about 12 carbon atoms, with from 4 to about 7 carbon atoms being preferred. In one embodiment, dicarboxylic acids are preferred.

[0034] Examples of suitable polyfunctional carboxylic acids include, but are not limited to, butanedioic acid, pentanedioic acid, hexanedioic acid, heptanedioic acid, octanedioic acid, nonanedioic acid, decanedioic acid, undecanedioic acid, dodecanedioic acid, carbonic acid, dimer acid, phthalic acid, isophthalic acid, terephthalic acid, and 2-6-naphthalenedicarboxylic acid, and derivatives and combinations thereof.

[0035] In a preferred embodiment, the polyfunctional carboxylic acid includes at least hexanedioic acid having the following formula: [ka]

[0036] Multifunctional alcohol The electrosurgical lubricant comprises a polymer derived from at least one polyfunctional alcohol. The polyfunctional alcohol has two or more alcohol (—OH) groups and, optionally, one or more additional functional groups. The polyfunctional alcohol can be aliphatic or aromatic. The polyfunctional alcohol can be linear or branched, depending on the type of electrosurgical lubricant to be formulated. Preferred polyfunctional alcohols have from 2 to about 10 carbon atoms.

[0037] Suitable polyfunctional alcohols include, but are not limited to, polyols such as diols, triols, tetraols, pentaols, hexaols, etc. Specific polyfunctional alcohols include, but are not limited to, glycerol, pentaerythritol, dipentaerythrityl, tripentaerythritol, trimethylolpropane, neopentyl glycol, propylene glycol, 1,3-butylene glycol, 2-methyl-1,3-propanediol, dipropylene glycol, ethylene glycol, cyclohexanedimethanol, and butylethylpropanediol, as well as derivatives and combinations thereof.

[0038] In one embodiment, propanediol is preferred and has the formula: [ka]

[0039] In a preferred embodiment, the conjugated polyester polymer has the formula: 18 H 36 O2·X(C6H 14 O3·C6H 10 O4) Y , where both X and Y can be varied to achieve the desired viscosity of the lubricant.

[0040] Bicomponent polyester polymers suitable for use in the lubricant compositions of the present invention are commercially available from sources such as Nyco America LLC of Newnan, Georgia and Zschimmer & Schwarz of Milledgeville, Georgia.

[0041] Method for preparing conjugated polyester polymers The conjugated polyester polymer is formed, in one embodiment, by combining appropriate amounts of at least one monofunctional carboxylic acid, at least one multifunctional carboxylic acid, and at least one multifunctional alcohol, and conducting an esterification reaction thereon.

[0042] In one embodiment, the reactants are added in the desired ratio to a suitable reactor and heated, preferably with stirring and under inert gas, at a temperature of about 180°C to about 230°C. One or more suitable catalysts may be utilized. In some embodiments, activated carbon may be added as a catalyst support and / or absorbent.

[0043] After the reaction has proceeded to the desired degree of completion to form the conjugated polyester polymer, the reaction product is recovered by purification methods known to those skilled in the art.

[0044] Other optional ingredients The lubricant compositions of the present invention may contain one or more optional additives or ingredients to impart desirable properties to the compositions. Examples of optional ingredients include, but are not limited to, viscosity modifiers, surfactants, antioxidants, pigments, dyes, preservatives, non-stick ingredients, fragrances, anti-inflammatory agents, perfuming ingredients, etc.

[0045] In some embodiments, the lubricant compositions of the present invention include a viscosity modifier that helps regulate the viscosity of the composition, thereby affecting the composition's flowability and ability to maintain contact with the desired portion of the electrosurgical device. Examples of viscosity modifiers include, but are not limited to, thickeners such as xanthan gum, guar gum, celluloses such as hydroxyethyl cellulose and hydroxypropyl methylcellulose, microcrystalline cellulose, methacrylates, alginates, gelatin, starch, pectin, and viscosity reducers such as, but not limited to, hexylene / propylene glycol and alcohol.

[0046] In some embodiments, the lubricant composition includes a component that can promote or participate in the formation of a non-stick surface on the probe. In some embodiments, the component can be suspended in the lubricant composition. In some embodiments, the lubricant composition includes a salt of the following formula: 1 (R 1 )(R 2 ) (calcium stearate) (II). In some embodiments, M 1 is a divalent cation. In some embodiments, R 1 and R 2 are independently -OC(O)C 10 ~C 25 Alkyl, -OC(O)C 10 ~C 25 Alkenyl, or -OC(O)C 10 ~C 25 In some embodiments, C is alkynyl. 10 ~C 25 Alkyl, C 10 ~C 25 Alkenyl, or C 10 ~C 25Each hydrogen atom in the alkynyl is independently optionally selected from halo, hydroxy, amino, oxo, or OR. 3 In some embodiments, R 3 are independently H, C1-C6 alkyl, C1-C6 alkenyl, C1-C6 alkynyl, C 10 ~C 25 Alkyl, C 10 ~C 25 Alkenyl, C 10 ~C 25 Alkynyl, -C(O)C1-C6 alkyl, -C(O)C1-C6 alkenyl, -C(O)C1-C6 alkynyl, -C(O)C 10 ~C 25 Alkyl, -C(O)C 10 ~C 25 Alkenyl, -C(O)C 10 ~C 25 Alkynyl, C1-C6 alkyl, C1-C6 alkenyl, C1-C6 alkynyl, C 10 ~C 25 Alkyl, C 10 ~C 25 Alkenyl, C 10 ~C 25 Alkynyl, -C(O)C1-C6 alkyl, -C(O)C1-C6 alkenyl, -C(O)C1-C6 alkynyl, -C(O)C 10 ~C 25 Alkyl, -C(O)C 10 ~C 25 Alkenyl, -C(O)C 10 ~C 25 Each hydrogen atom in the alkynyl is independently optionally substituted with halo, hydroxy, or amino. In some embodiments, the divalent cation is magnesium, calcium, or iron. In some embodiments, the salt of Formula II comprises a stearate. In some embodiments, the salt of Formula II is calcium stearate.

[0047] In some embodiments, M 1 is a monovalent cation and R 1 or R 2In some embodiments, the lubricant composition comprises a stearate salt. In some embodiments, the lubricant composition comprises sodium stearate.

[0048] In some embodiments, the lubricant composition comprises a flavoring. In some embodiments, the flavoring comprises an essential oil. In some embodiments, the flavoring oil is mace essential oil.

[0049] The lubricant composition may include a certain weight percentage of flavoring. In some embodiments, the flavoring is at least about 1 wt. %, at least about 3 wt. %, at least about 5 wt. %, or at least about 10 wt. % of the lubricant composition. In some embodiments, the flavoring is up to about 25 wt. %, up to about 20 wt. %, or up to about 15 wt. % of the lubricant composition. The flavoring may be about 2 wt. %, about 3 wt. %, about 4 wt. %, about 5 wt. %, about 6 wt. %, about 7 wt. %, about 7.5 wt. %, about 8 wt. %, about 9 wt. %, about 10 wt. %, about 12 wt. %, about 15 wt. %, about 20 wt. %, or about 25 wt. % of the lubricant composition. The flavoring may be about 2 wt. % to about 25 wt. %, about 2 wt. % to about 20 wt. %, about 2 wt. % to about 15 wt. %, about 3 wt. % to about 12 wt. %, or about 5 wt. % to about 12 wt. % of the lubricant composition.

[0050] In some embodiments, the lubricant composition includes at least one antioxidant. Antioxidants can protect fatty components from thermal degradation. Additionally, antioxidants can act as preservatives and aid in the body's healing process. In some embodiments, the at least one antioxidant includes tocopherol or lipoic acid. In some embodiments, the antioxidant includes a mixture of tocopherols. In some embodiments, the lipoic acid is alpha-lipoic acid.

[0051] The lubricant composition may include at least one antioxidant in a specific weight percentage. In some embodiments, the at least one antioxidant is at least about 1 wt % or at least about 3 wt % of the lubricant composition. In some embodiments, the at least one antioxidant is up to about 20 wt %, up to about 15 wt %, or up to about 10 wt % of the lubricant composition. The at least one antioxidant may be about 1 wt %, about 2 wt %, about 3 wt %, about 4 wt %, about 5 wt %, about 6 wt %, about 7 wt %, about 7.5 wt %, about 8 wt %, about 9 wt %, about 10 wt %, about 12 wt %, about 15 wt %, or about 20 wt % of the lubricant composition. The at least one antioxidant may be about 1 wt % to about 20 wt %, about 1 wt % to about 15 wt %, about 1 wt % to about 10 wt %, or about 2 wt % to about 8 wt % of the lubricant composition.

[0052] In some embodiments, the lubricant composition comprises at least one anti-inflammatory agent. In some embodiments, the at least one anti-inflammatory agent comprises caryophyllene or a botanical aromatic substance. In some embodiments, the botanical aromatic substance comprises a terpene.

[0053] The lubricant composition may include at least one anti-inflammatory agent in a specific weight percentage. In some embodiments, the at least one anti-inflammatory agent is at least about 1% or at least about 2% by weight of the lubricant composition. In some embodiments, the at least one anti-inflammatory agent is up to about 20%, up to about 15%, or up to about 10% by weight of the lubricant composition. The at least one anti-inflammatory agent may be about 1%, about 2%, about 3%, about 4%, about 5%, about 6%, about 7%, about 7.5%, about 8%, about 9%, about 10%, about 12%, about 15%, or about 20% by weight of the lubricant composition. The at least one anti-inflammatory agent may be about 1% to about 20%, about 1% to about 15%, about 1% to about 10%, or about 2% to about 8% by weight of the lubricant composition.

[0054] In some embodiments, the lubricant composition may include a flavoring ingredient. In some embodiments, the flavoring ingredient is an oil-based flavoring. In some embodiments, the flavoring ingredient is biocompatible. In some embodiments, the flavoring ingredient is selected from the group consisting of hexyl acetate, fructone, ethyl methyl phenyl glycidate, and combinations thereof. In some embodiments, the flavoring ingredient is hexyl acetate. In some embodiments, the flavoring ingredient is a fructone. In some embodiments, the flavoring ingredient is ethyl methyl phenyl glycidate. In some embodiments, the flavoring ingredient comprises a lactone. Additional disclosure regarding flavoring ingredients may be found in U.S. Patent Application Publication No. 2017 / 049938, the entire contents of which are expressly incorporated herein by reference.

[0055] viscosity In an important aspect of the present invention, the electrosurgical lubricant has a viscosity high enough to allow for desirable coating of the electrosurgical device and stability of the lubricant after application onto the device, so that the lubricant does not appreciably drip or run off the device. Thus, in one embodiment of the present invention, the lubricant comprising the composite polyol polyester polymer has a viscosity in the range of greater than 5,000 centipoise (5 Pa·s) to about 15,000 centipoise (15 Pa·s), desirably from about 6,000 centipoise (6 Pa·s) to about 12,000 centipoise (12 Pa·s), and preferably from about 8,000 centipoise (8 Pa·s) to 11,000 centipoise (11 Pa·s) at 25°C, as measured according to ASTM D7042.

[0056] The viscosity of the lubricant can be controlled in one embodiment by adjusting the molecular weight of the polymer, with higher molecular weight polymers generally providing higher viscosities. Additionally, the viscosity can be adjusted by including other optional viscosity-adjusting ingredients in the lubricant, as previously discussed.

[0057] molecular weight Gel permeation chromatography (GPC) was used to determine the molecular weight distribution of exemplary polymers of the synthetic electrosurgical lubricant composition. GPC studies were performed by dissolving 10 mg of the electrosurgical lubricant composition polymer in 10 g of chloroform. Solutions were prepared and analyzed in duplicate along with a series of narrow molecular weight polystyrene standards. GPC analysis conditions were as follows: [Table 1]

[0058] GPC revealed that the electrosurgical lubricant composition polymers had a multimodal distribution. More specifically, five distinct distribution peaks were found for the tested compositions. Without being bound by theory, it is believed that the multimodal distribution arises from chain branching and / or termination events that do not occur simultaneously on all chains.

[0059] The first distribution peak is 5-20% of the total weight of the electrosurgical lubricant composition polymer and has a weight average molecular weight (M w ) was generally in the range of 25,000 to 400,000, desirably 50,000 to 300,000, and preferably 100,000 to 200,000.

[0060] The second distribution peak is 50-65% of the total weight of the electrosurgical lubricant composition polymer and has a weight average molecular weight (M W ) was generally in the range of 2,000 to 40,000, desirably 5,000 to 30,0000, and preferably 8,000 to 22,000.

[0061] The third distribution peak is 3-18% of the total weight of the electrosurgical lubricant composition polymer and has a weight average molecular weight (M W ) was generally in the range of 500 to 7,000, desirably 1,000 to 5,500, and preferably 1,500 to 3,500.

[0062] The fourth distribution peak is 9-24% of the total weight of the electrosurgical lubricant composition polymer and has a weight average molecular weight (M W ), generally in the range of 100 to 7,000, desirably 500 to 5,000, and preferably 1,000 to 3,000.

[0063] The fifth distribution peak is 1-16% of the total weight of the electrosurgical lubricant composition polymer and has a weight average molecular weight (M W ) was generally in the range of 50 to 1,000, desirably 100 to 700, and preferably 200 to 500.

[0064] Other attributes The electrosurgical lubricant of the present invention, as described above, exhibits one or more, preferably all, of the following desirable properties: no or low current impedance to the electrosurgical device, easy removal from the electrosurgical device, and minimal adhesion of the electrosurgical device to tissue. The lubricant also has a relatively high flash point, making it thermally stable at temperatures exceeding 175°C, 200°C, 250°C, or 550°F (288°C). The lubricant also exhibits low odor, even after aging. Furthermore, the electrosurgical lubricant of the present invention significantly reduces the amount of eschar that accumulates on the electrosurgical device compared to prior art lubricants, such as soy lecithin.

[0065] In a preferred embodiment, the electrosurgical lubricant is protein-free. As is well known to those skilled in the art, proteins can cause allergic reactions in some patients.

[0066] sterility In an important aspect of the present invention, the electrosurgical lubricant is a sterile composition. Sterility is very important to prevent the introduction of pathogens into the sterile surgical field. In one embodiment, the electrosurgical lubricant is sterilized by the use of radiation. Ionizing radiation, which utilizes short wavelength, high intensity radiation to destroy microorganisms, can be used. Examples include X-rays and gamma rays, although in one embodiment, X-rays are preferred.

[0067] The radiation dose applied varies depending on the composition of the electrosurgical lubricant. The radiation dose should be sufficient to kill organisms. In various embodiments, a radiation dose of 20 to 55 kGy is utilized to maintain sterility.

[0068] stability Importantly, no significant change in viscosity was observed when the electrosurgical lubricant of the present invention was irradiated to sterilize the composition. One embodiment of the electrosurgical lubricant was found to be stable for at least one year when irradiated at a dose of 51.1 to 54.9 kGy with respect to one or more of the following properties: homogeneity, color, clarity, and viscosity. In a preferred embodiment, the surgical lubricant is stable with respect to all four parameters.

[0069] Electrosurgical Instrument Lubrication Kit In a further important aspect of the present invention, a kit for lubricating an electrosurgical instrument is provided, the kit comprising a sealed package containing therein a sealed container containing an electrosurgical lubricant according to the present invention. Also contained within the sealed package is an applicator that can be utilized to apply the electrosurgical lubricant to the electrosurgical instrument.

[0070] The sealed container can be any suitable container that can adequately contain the electrosurgical lubricant and transport it to the point of use. In preferred embodiments, the container can withstand the radiation doses described herein. Suitable containers include, but are not limited to, jars, bottles, tubes, bags, pouches, vials, flasks, etc., that are appropriately sealed depending on the type of container. For example, jars, bottles, tubes, vials, flasks, etc., can be sealed with lids, caps, etc. Bags, pouches, etc., can be self-sealing or sealed with additional components, such as valves, depending on the manufacturer's desire for ease of use for the end user. Depending on the user's needs, the container can be rigid, such as glass or a hard polymer, or flexible, such as a polymer or elastomer, to aid in application or use.

[0071] Suitable applicators include, but are not limited to, those listed above, such as, for example, a sponge, wipe, brush, or cloth.

[0072] The sealed container, electrosurgical lubricant, and applicator may be shipped in a sealed package large enough to accommodate the sealed container and applicator.

[0073] Some embodiments of the sealed container use a tray, which is provided with a removable seal, such as plastic wrap.

[0074] In a preferred embodiment, the sealed package is a blister pouch, having a polymer film surface such as nylon with a flexible paper liner.

[0075] In a preferred embodiment, the electrosurgical instrument lubrication kit is sterile. The same sterilization methods described above may be utilized and are incorporated herein by reference. When the kit is irradiated, all contents within the sealed package are sterilized and suitable for use in the intended surgical field.

[0076] In a preferred embodiment, the electrosurgical lubricant is packaged in a polymeric bottle with a screw cap. In some embodiments, when a solid container is utilized, the fill level ranges from 20 to 70, 30 to 60, or 40 to 60 percent, allowing sufficient headroom so that the electrosurgical device can be immersed in the bottle without spilling the contents, i.e., the electrosurgical lubricant.

[0077] How to use lubricants One method of lubricating an electrosurgical device includes obtaining an electrosurgical device and applying a lubricant comprising a composite polyester polymer to a surface thereof.

[0078] The lubricant may be applied directly by immersing the electrosurgical device directly into a container containing the lubricant.

[0079] Alternatively, the lubricant may be applied by indirect application, where the lubricant is first applied to an applicator such as a sponge, wipe, brush, cloth, etc. The applicator is then used to apply the lubricant to the electrosurgical device by wiping, brushing, etc. The lubricant should be applied so that it is evenly distributed on all surfaces of the electrosurgical device adapted to contact the patient.

[0080] In a preferred embodiment, the applicator is radiopaque and appears to utilize standard medical radiological equipment.

[0081] If necessary, the lubricant can be reapplied to the device during surgery. [Example]

[0082] The following tests used electrosurgical lubricant compositions according to the present invention, which comprised a polymer derived from the reaction product of at least one monofunctional carboxylic acid, at least one polyfunctional carboxylic acid, and at least one polyfunctional alcohol, and had a viscosity of 6,000 to 15,000 centipoise (6 Pa·s to 15 Pa·s).

[0083] Coating Ability Test The ability of the electrosurgical lubricant to completely coat the electrode without excessive dripping depends on the viscosity and rheology of the product.

[0084] The ability of the exemplary electrosurgical lubricant composition to coat a planar electrode without excessive dripping was evaluated by immersing a planar blade electrode in a 10 mL bottle containing 4 mL of lubricant. The electrode was visually inspected for coating integrity. Additionally, the electrode was held at a 45-degree angle for 2 minutes, and the number of drips during that time was recorded for both the exemplary electrosurgical lubricant composition and the soy lecithin lubricant.

[0085] The test results showed that although both lubricants coated the electrosurgical device 100%, the soy lecithin lubricant exhibited an average of more drops (3.1 drops) than the exemplary electrosurgical lubricant (2.4 drops) over the two-minute test period. This result was found to be statistically significant, indicating superior performance by the exemplary electrosurgical lubricant.

[0086] Coating ability testing was repeated after 92 days of accelerated storage at 60°C to mimic aged materials. After accelerated aging, both the electrosurgical lubricant composition and the soy lecithin lubricant demonstrated 100% coating effectiveness on the electrosurgical device. The soy lecithin lubricant exhibited, on average, more droplets (2.6 drops) than the electrosurgical lubricant composition (1.7 drops) during the two-minute test period. This result was found to be statistically significant.

[0087] Cutting Force Test It is important that the electrosurgical lubricant does not impede the flow of electrical current during use. The presence of this current impedance can be observed indirectly by measuring the cutting force required to insert the electrosurgical blade into the substrate. The cutting force required for a planar blade electrode can be measured by cutting a substrate placed on a top load balance and measuring the force gravimetrically in grams.

[0088] Studies were conducted using uncoated electrodes, commercially available electrodes coated with polytetrafluoroethylene (PTFE), electrodes coated with soy lecithin, and electrodes coated with an exemplary electrosurgical lubricant. Once a set energy profile (power setting of 30 watts at the cut-mode frequency) was applied, the electrodes were inserted vertically into chicken tissue to a predetermined depth. The downward force required to cut to the predetermined depth was measured in grams.

[0089] The cutting force required for the uncoated electrode was found to be 139.7 g. The cutting force required for the PTFE-coated electrode was 90.8 g, and the cutting force required for the soy lecithin-coated electrode was 72.3 g. Finally, the electrode coated with the exemplary electrosurgical lubricant required only 39.4 g. These results demonstrate that neither coating condition interferes with the delivery of electrical current. Furthermore, the exemplary electrosurgical lubricant reduced the required cutting force compared to all other coating conditions, demonstrating its superior performance as an electrosurgical lubricant.

[0090] To mimic aged materials, the cutting force test was retested after 92 days of accelerated storage at 60°C. When the aged materials were tested, it was found that the flat blade electrode coated with soy lecithin required an average downward force of 89.9 g, while the exemplary electrosurgical lubricant required only 50.5 g. This demonstrates that the exemplary electrosurgical lubricant outperforms soy lecithin even under aged conditions.

[0091] Electrode adhesion test to tissue Electrodes that stick or adhere to tissue during cutting can damage surrounding tissue and increase bleeding at the surgical site, so it is important that electrosurgical lubricants reduce electrode adhesion to tissue.

[0092] The ability of the electrodes to prevent adhesion to tissue was assessed gravimetrically by placing the chicken substrate on a top-load balance. Each electrode was applied to the chicken tissue, and once "burning" was complete, the electrode remained in contact with the tissue for 2 seconds before being lifted from the tissue. The change in weight was measured when the electrode was removed from the tissue. High adhesion resulted in a large negative change in weight when the chicken tissue was lifted from the balance surface.

[0093] This study was conducted using uncoated ball electrodes, ball electrodes coated with soy lecithin, or ball electrodes coated with an exemplary lubricant. Uncoated electrodes demonstrated the highest adhesion with an average weight change of -110.0 g, while soy lecithin demonstrated lower adhesion than uncoated electrodes with an average weight change of -66.1 g. The exemplary lubricant demonstrated the best performance as an electrosurgical lubricant with the least tissue adhesion, an average weight change of only -32.6 g.

[0094] Eschar test The crust that forms on electrosurgical blades during electrosurgery can reduce blade performance and must be periodically removed from the blade to prevent crust buildup. Therefore, it is important that electrosurgical lubricants not only facilitate crust removal, but also reduce the amount of crust that accumulates on the blade with each cut.

[0095] The buildup of eschar and the subsequent ease of eschar removal were measured using uncoated electrosurgical blades, blades coated with soy lecithin, and blades coated with an exemplary electrosurgical lubricant. The evaluation was performed using an electrosurgical unit at 50 watts (maximum power setting) and sufficient burn in coagulation mode to produce a large amount of eschar on the uncoated electrode. The same number of burns were then performed on the electrodes under both coating conditions. After burning, the blades were wiped five times with a dry Kimwipe® to determine how easily the eschar buildup could be removed.

[0096] The results of the study are shown in Figure 1. The study showed that after four burns, the uncoated electrode accumulated the most eschar, with some tissue remaining attached to the electrode even after wiping. Electrodes coated with soy lecithin formed less eschar, but a thin charred layer remained on the electrode after five wipes. Electrodes coated with the exemplary electrosurgical lubricant accumulated the least eschar over four burns and returned to clean metal after five wipes.

[0097] flash point Electrodes during electrosurgery can become very hot due to the flow of electrical current, so it is important that an electrosurgical lubricant have a high flash point for safe use during electrosurgery.

[0098] Soybean lecithin had a flash point of 150°C, while the exemplary electrosurgical lubricant composition had a flash point of 290°C as measured by Cleveland Open Cup (COC, ASTM D92).

[0099] Odor evaluation Odor evaluations were conducted by a panel of randomly selected test participants. The panel evaluated the odor of exemplary electrosurgical lubricant compositions and soy lecithin. The odor of each product was rated on a scale of 1 to 5, with 1 meaning no malodor and 5 meaning a strong malodor.

[0100] The odor profile of the exemplary electrosurgical lubricant composition was rated more favorably by the panel than soy lecithin.

[0101] To mimic aged material, the odor evaluation test was repeated after 92 days of accelerated storage at 60° C. Panelists again rated the odor profile of the exemplary electrosurgical lubricant as more preferable than the soy lecithin lubricant, and the difference in preference between the two aged profiles was wider than that observed in the initial test using unaged material.

[0102] Electrode Protection Instruments used during electrosurgical procedures can be damaged during surgery and by the aggressive reprocessing procedures typically required to remove burnt eschar from reusable electrosurgical devices. The use of an effective electrosurgical lubricant can reduce damage to the device over time.

[0103] An uncoated electrosurgical blade, a blade coated with soy lecithin, and a blade coated with an exemplary electrosurgical lubricant composition were used 10 times and examined using a scanning electron microscope (SEM) to determine the level of damage caused by the planar blade electrode. Black marks in Figure 2 indicate the presence of damage.

[0104] It can be seen from Figure 2 that the uncoated blade suffered the most damage and the blade coated with the exemplary electrosurgical lubricant suffered the least damage.

[0105] Example of an electrosurgical lubrication kit Four milliliters of the exemplary electrosurgical lubricant composition described above is packaged in a 10-mL bottle with a removable screw cap. A fill factor of approximately 40% provides ample volume to allow the electrosurgical device blade to be immersed in the bottle without spilling the contents. The bottle is filled with a radiopaque surgical sponge with an adhesive lining, allowing the end user to apply the lubricant to the device instead of dipping it into the device. The bottle and sponge were sealed in a blister pouch with a nylon film surface and a flexible paper lining.

[0106] Irradiation stability To test the physical stability of exemplary electrosurgical lubricant compositions against applied radiation, packaged materials were exposed to X-ray irradiation at doses of 51.1 to 54.9 kGy. The resulting irradiated electrosurgical lubricant compositions were then stored under accelerated conditions, i.e., 40°C and 75% relative humidity, for six months to strongly promote further degradation. The irradiated electrosurgical lubricant compositions were tested initially and then again after one month and six months of storage to evaluate lubricant homogeneity, color, clarity, viscosity, and package appearance.

[0107] The exemplary lubricant compositions were found to be stable under relatively high radiation doses (>50 kGy) in all parameters tested.

[0108] For the avoidance of doubt, the compositions and methods of the present invention encompass all possible combinations of ingredients disclosed herein, including the various ranges of the ingredients described above. It is further noted that the term "comprising" does not exclude the presence of other elements. However, it is also understood that a description of a product comprising certain ingredients also discloses a product consisting of those ingredients. Similarly, it is also understood that a description of a process comprising certain steps also discloses a process consisting of those steps.

[0109] While in accordance with the patent statutes, the best mode and preferred embodiment has been described, the scope of the invention is not limited thereto, but rather by the appended claims.

Claims

1. 1. An electrosurgical lubricant comprising a polymer derived from the reaction product of at least one monofunctional carboxylic acid, at least one multifunctional carboxylic acid, and at least one multifunctional alcohol, said lubricant having a viscosity of greater than 5,000 centipoise (5 Pa·s) to about 15,000 centipoise (15 Pa·s) at 25°C as measured in accordance with ASTM D7042.

2. 2. The lubricant of claim 1, wherein the monofunctional carboxylic acid has from about 4 to about 24 carbon atoms, the polyfunctional carboxylic acid has from 2 to about 12 carbon atoms, and the polyfunctional alcohol has from 2 to about 10 carbon atoms.

3. The monofunctional carboxylic acid is one or more of 2-methylpropanoic acid, benzoic acid, 2-ethylbutyric acid, hexanoic acid, heptanoic acid, 2-ethylhexanoic acid, octanoic acid, nonanoic acid, 3,5,5-trimethylhexanoic acid, isononanoic acid, decanoic acid, isooctadecanoic acid, dodecanoic acid, 2-methylbutyric acid, isopentanoic acid, pentanoic acid, 2-methylpentanoic acid, 2-methylhexanoic acid, isooctanoic acid, undecylic acid, isolauric acid, isopalmitic acid, isostearic acid, and behenic acid, or derivatives thereof; and the polyfunctional carboxylic acid is butanedioic acid, pentanedioic acid, hexanedioic acid, heptanedioic acid, octanedioic acid, nonanedioic acid, decanedioic acid, undecylic acid, octanedioic ...

3. The lubricant of claim 2, wherein the polyfunctional alcohol is one or more of decanedioic acid, dodecanedioic acid, carbonic acid, dimer acid, phthalic acid, isophthalic acid, terephthalic acid, and 2-6-naphthalenedicarboxylic acid, or derivatives thereof, and the polyfunctional alcohol is one or more of glycerol, pentaerythritol, dipentaerythrityl, tripentaerythritol, trimethylolpropane, neopentyl glycol, propylene glycol, 1,3-butylene glycol, 2-methyl-1,3-propanediol, dipropylene glycol, ethylene glycol, cyclohexanedimethanol, and butylethylpropanediol, or derivatives thereof.

4. 4. The lubricant of claim 3, wherein the monofunctional carboxylic acid comprises isooctodecanoic acid, the polyfunctional carboxylic acid comprises hexanedioic acid, and the polyfunctional alcohol comprises propanediol.

5. 5. The lubricant of claim 4, wherein the composition further comprises one or more of a viscosity modifier, a surfactant, an antioxidant, a pigment, a dye, a preservative, a non-stick ingredient, a fragrance, a perfuming ingredient, and an anti-inflammatory agent.

6. 10. The lubricant of claim 1, wherein the viscosity ranges from 6,000 centipoise (6 Pa·s) to 12,000 centipoise (12 Pa·s) as measured according to ASTM D7042.

7. 10. The lubricant of claim 1, wherein the viscosity ranges from 8,000 centipoise (6 Pa.s) to 11,000 (11 Pa.s) centipoise, as measured according to ASTM D7042.

8. 10. The lubricant of claim 1, wherein the lubricant has a flash point greater than 175°C, the electrosurgical lubricant is protein-free, and the electrosurgical lubricant is sterile.

9. 2. The lubricant of claim 1, wherein the polymer has a multimodal distribution with a first distribution peak comprising 5-20% of the total polymer weight and having a weight average molecular weight of 25,000-400,000; a second distribution peak comprising 55-60% of the total polymer weight and having a weight average molecular weight of 2,000-40,000; a third distribution peak comprising 3-18% of the total polymer weight and having a weight average molecular weight of 500-7,000; a fourth distribution peak comprising 9-24% of the total polymer weight and having a weight average molecular weight of 100-7,000; and a fifth distribution peak comprising 1-16% of the total polymer weight and having a weight average molecular weight of 50-1,000.

10. 1. A method of lubricating an electrosurgical device, comprising: obtaining the electrosurgical device; and applying the electrosurgical lubricant of claim 1 to at least a portion of the electrosurgical apparatus.

11. 1. A method of lubricating an electrosurgical device, comprising: obtaining the electrosurgical device; and applying the electrosurgical lubricant of claim 3 to at least a portion of the electrosurgical apparatus.

12. 1. A kit for lubricating an electrosurgical instrument, comprising: A sealed package containing: a sealed package comprising: a sealed container containing an electrosurgical lubricant comprising a polymer derived from the reaction product of at least one monofunctional carboxylic acid, at least one polyfunctional carboxylic acid, and at least one polyfunctional alcohol, said lubricant having a viscosity of greater than 5,000 centipoise (5 Pa·s) to about 15,000 centipoise (15 Pa·s) at 25°C as measured in accordance with ASTM D7042; an applicator that can be used to apply the electrosurgical lubricant to an electrosurgical instrument; The kit, wherein the sealed container, electrosurgical lubricant, and applicator are sterile.

13. 13. The kit of claim 12, wherein the monofunctional carboxylic acid has from about 4 to about 24 carbon atoms, the polyfunctional carboxylic acid has from 2 to about 12 carbon atoms, and the polyfunctional alcohol has from 2 to about 10 carbon atoms.

14. The monofunctional carboxylic acid has from about 4 to about 24 carbon atoms, the polyfunctional carboxylic acid has from 2 to about 12 carbon atoms, the polyfunctional alcohol has from 2 to about 10 carbon atoms, the monofunctional carboxylic acid is one or more of 2-methylpropanoic acid, benzoic acid, 2-ethylbutyric acid, hexanoic acid, heptanoic acid, 2-ethylhexanoic acid, octanoic acid, nonanoic acid, 3,5,5-trimethylhexanoic acid, isononanoic acid, decanoic acid, isooctadecanoic acid, dodecanoic acid, 2-methylbutyric acid, isopentanoic acid, pentanoic acid, 2-methylpentanoic acid, 2-methylhexanoic acid, isooctanoic acid, undecylic acid, isolauric acid, isopalmitic acid, isostearic acid, and behenic acid, or derivatives thereof, and the polyfunctional carboxylic acid is butanedioic acid, pentanediol, benzoic acid ...

14. The kit of claim 13, wherein the polyfunctional alcohol is one or more of pentanediol, hexanedioic acid, heptanedioic acid, octanedioic acid, nonanedioic acid, decanedioic acid, undecanedioic acid, dodecanedioic acid, carbonic acid, dimer acid, phthalic acid, isophthalic acid, terephthalic acid, and 2-6-naphthalenedicarboxylic acid, or derivatives thereof, and the polyfunctional alcohol is one or more of glycerol, pentaerythritol, dipentaerythrityl, tripentaerythritol, trimethylolpropane, neopentyl glycol, propylene glycol, 1,3-butylene glycol, 2-methyl-1,3-propanediol, dipropylene glycol, ethylene glycol, cyclohexanedimethanol, and butylethylpropanediol, or derivatives thereof.

15. 15. The kit of claim 14, wherein the sealed container comprises a jar, bottle, tube, bag, pouch, vial, or flask, and the applicator is one or more of a sponge, wipe, brush, and cloth.

16. 16. The kit of claim 15, wherein the viscosity ranges from 6,000 centipoise (6 Pa.s) to 12,000 centipoise (12 Pa.s) when measured according to ASTM D7042.

17. 16. The kit of claim 15, wherein the sterilization is performed by exposing the sealed package to a radiation dose of 20 to 55 kGy.

18. 1. A method of manufacturing an electrosurgical instrument lubrication kit, comprising: adding the electrosurgical lubricant of claim 1 to a container; sealing the container; placing the sealed container and applicator within a package; sealing the package with the sealed container and applicator therein; exposing the sealed package to 20-55 kGy of radiation to sterilize the sealed package, the sealed container with electrosurgical lubricant therein, and the applicator.

19. 20. The method of claim 18, wherein the sealed package is exposed to gamma or x-ray radiation.

20. 20. The method of claim 19, wherein the monofunctional carboxylic acid has from about 4 to about 24 carbon atoms, the polyfunctional carboxylic acid has from 2 to about 12 carbon atoms, and the polyfunctional alcohol has from 2 to about 10 carbon atoms, the sealed container comprises a jar, bottle, tube, bag, pouch, vial, or flask, and the applicator is one or more of a sponge, wipe, brush, and cloth.

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