WO2007127792A2

WO2007127792A2 - Biocompatible self-lubricating polymer compositions and their use in medical and surgical devices

Info

Publication number: WO2007127792A2
Application number: PCT/US2007/067407
Authority: WO
Inventors: Xiaoping Guo; Richard E. Stehr
Original assignee: St Jude Medical Atrial Fibrillation Division Inc
Current assignee: St Jude Medical Atrial Fibrillation Division Inc
Priority date: 2006-04-28
Filing date: 2007-04-25
Publication date: 2007-11-08
Anticipated expiration: 2008-10-28
Also published as: US9931440B2; WO2007127792A3; US20070254000A1; US20180207322A1; US20170312396A1

Abstract

The invention comprises self-lubricating polymer compositions that are especially useful in medical devices 10 and valves 200 and gaskets 43 of medical devices 10. In a preferred embodiment the poly met compositions comprise a theim?setting or thermoplastic silicone elastomer in combination with a lubricity enhancing polyfluQiopoiyether fluid or hydrocarbon-based synthetic oil In other preferred embodiments, the poly met compositions contain only biocompatible components The improved ami-friction properties of the self-lubricating polymers can be demonstrated over a course of insertion and w ithdrawal cycles, where conventional polymers have changing and mostly increasing force required for each insertion and withdrawal, while the polymer compositions of the invention remain stable.

Description

BiOCOMPA FlBLE SELF-LUBRICATING POLYMER COMPOSITIONS AND THEI R USE IN MEDICAL AMD SURGICAL DEVICES

CROSS-REFERENCE TO RELATED APPLICATIONS

JOOOIj This application claims the benefit of United States provisional application no. 60/795,503 filed on April 28, 2OC)(S (the ^' 593 application). This application also claims the benefit of United States application no. 1 1/482,814, filed 10 July 2006 (the ¹SH application), now pending. The \593 application and the ~814 applications are both hereby incorporated by reference as though fully set forth herein.

BACKGROUND OF THE INVENTION a. Field of the Inventi Oil

[00021 The invention relates to polymer compositions with enhanced anti-friction properties for use in medical applications and medical devices. The polymer compositions have reduced friction characteristics and can be implemented in tubing, gaskets, valves., and in a variety of insertion devices and other devices used in procedures to introduce objects into the body, for example.

b. Background Art

[00031 ^ growing number of surgical or medical procedures employ devices and kits that rely on inserting a device or tube through a sealed valve or apparatus. For example, catheters and guides are typically inserted through a sterile valve to introduce fluids, intraluminal devices and marry other instruments into the body or into the lumen of a blood vessel. In fact, various surgical kits now include valves and devices to assist in the simultaneous, sterile insertion of multiple elements into vessels or elsewhere in the body. To operate properly, the valves must be capable of accepting different sized elements, be sufficiently pliable and/or elastic to maintain a seal during manipulation, and allow the user to effectively introduce and remove devices under sufficient control to avoid damage to vessels or other body tissue. However, pliable or flexible polymers tend to cause a degree of friction when an element is inserted or withdrawn into or through them. During medical or surgical procedures, this friction is undesirable and may lead to a lack of control and require forceful insertion or withdrawal. Some kits and procedures even require multiple guklewtre and catheter exchange steps, for example, which exacerbates the insertion and withdrawal problems. The sealed or sealable valves used must also prevent the introduction of air into a blood vcs.se! and/or contamination of body tissue during insertion and withdrawal Because of these and other requirements, the safe insertion and withdrawal, as well as the related force:, used to insert and withdraw, has become a problem with many devices and kits used today To attempt to alleviate this problem, silicone oil is customarily used to externally lubricate the s a! ves and de\ ices During a medical procedure this lubricant can he wiped away or lose its effectiveness after even a single insertion and withdrawal action

[0004] A high performance hemostasia valve has recently been described thai can be sealed effectively to prevent leaks and contamination and which is capable of accepting various catheters having a variety of diameters, {see, for example, US 6,632,200) As described below, the inventors^" improvements on this and many other devices, w hich in part addresses the friction problem during insertion and withdrawal noted above, includes a self-lubricating pυh mei composition that effectively allows elements to slide in and out of valves, other devices, tubes, or through tissue in a more controlled and easier manner Accordingly, the use of the self-lubricating polymer compositions of the invention improves the performance and use of a variers of medical and surgical devices and kits in addition, the polymer compositions can be used to improve basic cathetei arid tubing applications, or wherever one material slides over or across anothei material in a sealed or scalable device, valve, or gasket

BRIEF SUMMARY OF THE INVENTION

|0005] In one aspect, the Invention addresses the use of a self-lubricating polymer composition to make at least a part of or element to a medical or surgical device, or a kit comprising such medical or surgical dc\ ices In some applications, it is desirable for these polymeis to be flexible enough to form a sufficient seal around the surface of any element inserted into it and/or in contact with it during the course of using the device For example, the self-lubricating polymer can be used as a gasket at oi around the insertion site of a guide or catheter Similarly, the guide or catheter itself can be made of. or at least partially made of, the self-lubricating, polymer

J0006] in a general aspect, the invention addresses the use of a polymer material at a semidynamic seak such as where one part moves along, slides over, or contacts another part or element in the practice or use of a medical or surgical device, and/or at a d\ namie seal, where two or more parts similarly contact or move against each other Various gaskets, valves, covers and other sealing structures can be used in medical and surgical devices to produce a semidynamic or dynamic seal Thus, any of the existing and/or future sealing structures can be improved through the use of the polymer compositions of the invention.

|0007] hi another general aspect, the invention provides self-lubricating or enhanced lubricity polymer compositions for use in medical and surgical devices and related applications. The term lubricity is used in the conventional sense of a lubricating characteristic that effectively reduces friction between rubbing or contact surfaces Lubricity can be most important in conditions of boundary lubrication and/or for continuously maintaining a low surface-energy and/or to effectively repel body fluids and the resulting drag forces on contact surfaces. By increasing the lubricity of the polymer material used, the degree of deformation can be limited for a particular structure to form or maintain a leak-proof seal, while the force needed to slide over or through the structure is reduced A preferred example of a self-lubricating polymer composition comprises a biocompatible elastomer, and especially preferred is a biocompatible silicone elastomer. Other biocompatible blends of elastomers and/or thermoplastic polymers can also be used, as known in the art. The self-lubricating compositions also comprise one or more lubricants, such as synthetic oils and/or solid lubricants. Preferred synthetic oil lubricants are polyfluoropolyether (PFPE) synthetic oils, polytetrafluoroethylene (PTFE) synthetic oils, and hydrocarbon-based synthetic oils, namely co-oligomers of ethylene and olefins. Preferred solid lubricants include low molecular weight polytetrafluoroethylene powders, titanium dioxide micropowders, molybdenum disulfide micropowders, graphite micropovvders or flakes, and baron nitride micropowders and the like. Any combination of these lubricants and others available and/or used in the art for biocompatible materials can be selected, and preferred combinations are given in the Examples. |00081 As noted above, the self-lubricating polymer compositions can be used to produce one or more parts or elements in a medical or surgical device. In one preferred example, the part or element can comprise all or part of an insertion device or a receiving area for an inserted device or other elongated medical device. Typically, a receiving area employs a gasket or seal, which can readily and/or repeatedly permit passage of one or more devices, optionally of varying diameters. The gasket or seal or other receiving area is comprised of the polymer composition of the invention and thus has improved lubricity characteristics, for example with respect to a reduction in insertion and withdrawal forces compared to other materials and/or a reduction in the fluctuation of frictionai forces during repeated or regular use. The receiving area can also be or comprise a centering orifice for inserting a device, which functions to position or center the inserted device into a particular region. Furthermore, multilayered structures may also he used, wherein at least one layer comprises a self-lubricating composition of the invention, preferably a layer in contact with another component or against which frictionai forces are generated during use In a preferred example, the outer layer of an inserting device and/or the inner layer of a receiving area, such as a gasket, sheath or seal, comprises a biocompatible self-lubricating composition of the invention. In addition, various lengths of the inserting device or receiving area can comprise a self-lubricating polymer composition of the invention, anywhere from the entire insertion length, to less than 10% of the insertion length, to only the tip or inserting end of the insertion device, and even intermittent or non-contiguous sections covering a desired percentage of the insertion length can be used. Thus, a multilayered tube or sheath can be made and used, and one of skill in the art is familiar with molding and co-extrusion processes, for example, for producing these parts of medical devices

[0009] Accordingly, it is one object of the invention to provide a medical or surgical device that comprises a receiving area and/or insertion device made at least in part of a self-lubricating polymer composition. The parts, elements, biomedical, medical or surgical devices that contain the receiving areas or comprise insertion devices can thus exhibit improved anti-friction performance in the ease with which insertion and withdrawal of elongated elements or parts occurs and in {he maintenance of adequate sealing characteristics to avoid or substantially avoid leakage of fluids, blood, or the flow of air during use It is an additional object to provide a biocompatible polymer for use in biomedical applications, including human, veterinary, and biomedical research fields, wherein a self-lubricating polymer of the invention provides an improved lubricity surface for inserting into or withdrawing from or out of a variety of devices or body tissues.

[0010] Other objects, features, details, utilities, and advantages of the present invention will be apparent from the following more particular written description of various embodiments and examples of the invention, as further illustrated in the accompanying drawings and defined in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

|0011| Figure 1 depicts a cross-sectional view of preferred cardiac catheter device comprising hub 10 containing a hemostasia valve as exemplary receiving area, a stopcock assembly 12, a guidewire 20, and a catheter sheath or shaft 30 extending into the lumen of a vessel. The valve receiving area comprises a gasket, or sea! made of a self-lubricating polymer of the invention primarily comprising a silicone elastomer and a synthetic oil. The forces required to Introduce, manipulate, control, and/or withdraw the catheter device are substantially less than those when a conventional elastomer without modification is used for the gasket or seal .

|0012] Figure 2 depicts a close-up, cross-sectional view of an inserting device 200 inserted into a hemostasia valve, where various parts or elements of the valve can be made of the self-lubricating polymer of the invention. For example, sheath 100 (on its inner and/or outer surface) and gasket area 200 can both be composed of the self- lubricating polymer compositions of the invention to improve performance, such as anti-friction and sealing performance.

[0013] Figure 3 is a radial, cross-sectional view of a catheter sheath or shaft 120 passing through the gasket 43 of a valve, for example, similarly, any tubing used in or inserted into a body tissue can be made of a self-lubricating polymer composition of the invention.

|0014] Figure 4 shows exemplar}' results of aα insertion and withdrawal cycle performed on a hemostasia valve produced from the formulation in Example 1 . Each spike represents the forces measured in one of fourteen insertion/withdrawal cycles, and the ten separate lines represent one of ten different catheters inserted into the same hemostasia valve. Even after the unusually large number of insertions and withdrawals for a single hemostasia valve, the forces through each cycle are maintained at an acceptable level, at about 0.3 lbs on average, and within an advantageously small variance in the range of measured force.

|0015| Figure 5 shows the results of 96 insertion/withdrawal cycles of two different catheters through a conventional hemostasis valve made of unmodified silicone elastomers with external lubricating oil as typically used The increasing forces after about ten mseihυn/w ithdiawal cycles is the result of iubricating oils being icmoved oi wiped off ihe contacting sui faces The changes in foiees, from about 0 05 lbs to about 0 6 lbs, represent dramatically different forces that would be required to insert and withdraw Except for cycles 4-10, the forces vary fiorn neatly e\ cry cycle to the next

DKTA IL KD DESCRIPTION OF TlIK INVENTION

|OOI6] Throughout this disclosure applicants rdet to texts patent documents and othet sources of information One ski iled in the art can use the entire contents of any of the cited sources of information to make and use aspects of this invention Each and e\ ery cited source of tnfounation is specifically incotporatεd herein by reference in its entirety Portions of these sources may be included in this document as allowed or tequited However, the meaning of any term ot phtase specifically defined or explained m this disclosure shall not be modified by the content of any of the sources |0017] I he headings (such as '"Introduction" and "Brief Summary") used aie intended only for general organization of topics within the disclosure of the in\ ention and are not intended to limit the disclosure of the invention or any aspect of it In particular, subject matter disclosed m the "Introduction" includes aspects of technology within the scope of the invention and thus may not constitute background art Subject matter disclosed in the "Brief Summary^" is not an exhaustive or complete disclosure of the entire scope of the invention or any particular embodiment fOOIS] As υ^ed herein, the v\ords "preferred ^" "'ptefeientialK ,"^" and "pieferably^" tefei to embodiments of the inv ention that afford certain benefits, under certain circumstances Howev er, other embodiments may also be ptefeπed, undet the same or othei circumstances Furthermore, the recitation of one oi more preferred embodiments does not imply that other embodiments are not useful and is not intended to exclude other embodiments from the scope of ihe invention and no disclaimer of othet embodiments should be inferred from the discussion of a prefeπcd embodiment or a figure showing a preferred embodiment In fact, ihe nature of the polymei com positions of the invention allow one of skill in the art to make and use the im ention on anv medical or surgical device available or contemplated

{0019J The phrases "self-lubricating polymer composition,¹" "self-iuhricating composition,'^" and "polvmer composition of the invention^" all refei to a composition comprising a biocompatible pαlyme? υi blend of polymers and a biocompatible lubricant In preferred embodiments, the composition is composed of polymer compounds that have not previously been used together, or in a particular ratio or ration, for use in a medical, surgical or biomedical device

JO020] The invention i elates to the nev, , successful de\ elopmem of \ arious sejf- lubricaling polymer compositions, and especially silicone elastomer compositions, which can be used to make a variety of medical and surgical devices and thereby minimize friction forces- during use while maintaining sufficient sealing characteristics In one aspect, particular surfaces' os elements of devices comprise a self-lubπcatirtg polymer of the invention The medical devices of preferred interest include, but arc not limited to. hemostasis vai\ es of a \ ariety of types including those for cardiac catheteis, medical tubing, sheaths and gaskets used in \ alves and insertion devices, ultrasound catheters, and similar dev ices

|0021] In one general sense and without any intention to limit the scope to any particular explanation or mechanism for how it works, the invention provides a lubrication system for a polymer material, preferably a silicone elastomer material, through physical modifications of the polyniei matrix Pans o? components of a medical device can thus be made to exhibit an improved surface lubricity and result in low friction forces during use or in medical procedures, providing advantages by at least improving the ease of use and/or comfort to a patient Thus, it is one object of this invention to provide a self- lubrication mechanism foi a surface or polymer raatrk, such as a silicone elastomer matrix, such that any medical or siugical device made from the polymer matrix can release or spontaneously release embedded lubricant from the matrix or onto a contact surface(s) when the device is used. Accordingly, contact surface lubricity and the iesulting lowered factional forces during use can be reliably maintained throughout a proceduie Another object is to provide a lubrication system for a silicone elastomer that is biocompatible and can be used with a variety of medical and surgical deuces and parts or elements thereof further, the lubrication and anti-friction performance characteristics are not degraded but can actually be enhanced bs contact with blood, tissue, oi medical fluids |0022| In preferred embodiments, the polymer compositions of the invention are designed to act like a matrix that allows the lubricant contained within to continuously migrate to the surface of the part or device made of the polymer In effect, the lubricant is driven to the surface as the friction forces of the insertion and withdrawal cycles move the lubricant or wipe the lubricant

After manufacture, the surface of the polymer composition is essentially primed with lubricant As this lubricant is UMXI during insertion and withdrawal cycles, the lubricant in the matrix migrates to replace the surface lubricant The result is a constant friction foice throughout the insertion and withdrawal cycles Any of the polymer resins discussed here or in the xamples can form an effective matrix for migration of lubricant In addition, solid porous silica powder or similar powders can optionally be added to increase the amount of lubricant contained in the matrix. $0023] A number of polymers

e been suggested as self-iubri eating in a variet> of applications, including polyethylene, polyetheriniide, polypropy lene, polyetheretherketone ( PF.IϊIv), polytetrafluoroethylene (PI Fh) or Teflon (DuPont, Wilmington. Del ). 1 ltra High Molecular W eight (UHMW) polyethylene, μolyoxymethyiene or Deli in (Du Pont, Wilmington, De! ), pυlyanύde-hnide (PAl) or TORLOX (Solvay Adv ance Polymers, Alpharctta, GA), polyoxy methylene (POM), acctal resin, or Delrin (DuPont Wilmington, Del }, and polyvinylidcnc fluoride or Kv nar (Λtochem Corporation) Some of these polymers do not possess the combination of flexibility and lubricity desired foi the medical and surgical device applications noted herein 1 iouever, these polvmers ma> be modified with similar methods of the invention and used to produce catheters and sheaths, for example, having improved anti-friction propeitics Ftuthermore, the profeπed pohnier compositions of this invention are biocompatible, such as biocompatible thermosetting silicone elastomers and thermoplastic silicone elastomers

J0024] In designing or selecting an acceptable or optimum polymer or blend of polymers for a particular

ice or part thereof, a method of the invention can take into account the matrix-contiolled lubricant ielease mechanism fo optimize this mechanism or make it effective for a particular use, one can modify raw polymer compositions in one example, a silicone elastomer jesin can be cured with either organic peroxide erossiinking or, especially, by addition of a curing agent such as silicon hydride (SiH) and platinum as catalyst in the lattei appjoach, one can use IKJUUI and Of solid lubricants, and preteiably lubricants that are highly non-polar and chemically inert The chemical inert characteristics can be important in avoiding combinations that interfere with a curing agent. The lubricants can also ha\ e low surface energies that are compatible with the polymer or blends used and, in the case of the silicone elastomers, can be about 20 iriN/in (or dyne/cm). One or more lubricants with surface energies below 20 dyne/cm can be selected for isse, as explained below and in the Examples. Furthermore, the percentage of lubricant used and the amount available during the insertion and withdrawal use can be changed to arrive at a desirable level for the anti-friction function for a particular part or medical device or method contemplated. One of skill in the art is familiar with varying the amount of lubricants and with additional compounds or additives, such as porous silica powders and the like, for increasing the amount of lubricant that can effectively create an anti-friction polymer composition or material. f0025J In one method of producing the polymer compositions of the invention, the one or more lubricants are incorporated into the raw polymer or blend, such as the raw, gum- like silicone elastomer resin, with a two-roller mill compounding process as known in the art. After sufficient compounding to thoroughly mix the components, the lubricants are well dispersed into the matrix or occupy molecular pores within the matrix. To make a medical device part or element, the compounded polymer composition is molded, extruded or shaped and cured, In the case of a silicone elastomer, it is molded into shape and thermally cured. The curing process will create elastomerie, chemical crosslinks, which effectively trap the one or more lubricants in the polymer matrix. One can also consider the water repeiiency of non-polar lubricants and a lubricant concentration gradient from the center to the surface of the part. The limited chemical compatibility between the non-polar silicone elastomer and the non-polar lubricants, for example, can syuergistically control the release of the lubricants to the surface One of skill in the art is familiar with methods to produce concentration gradients.

{0026] Since silicone elastomers are one of the commonly used biomaterials in the medical device industry, the examples here and the preferred embodiments include silicone elastomers. However, the invention is not limited to the use of silicone elastomers or any particular polymer for that matter.

J0Θ27] Silicone elastomers possess high coefficients of friction and relatively lack lubricity characteristics, which leads to patient discomfort and potential tissue trauma during medical procedures. The high friction forces generated during the insertion and withdrawal of catheters through an introducer containing a silicone elastomer, such as a hemostasis valve, have routinely challenged the medical devices industry. In practice, a hemostasia valve is externally lubricated with silicone oil during manυfactυie During use, silicone oil is quickly iemosed by the insertion and withdrawal actions and. therefore, the lubricating effect from the silicone oil is quickly lost A^ a result the frictionai forces are extremely inconsistent during a medical piocedme and begin to vary from the first insertion At the beginning of a pioceduie, the faction foices are jelatively low due to the effect of the external!) added silicone oil, while iu the midst of a procedure the foices jump to an extreme!) high

as the oi! dissipates, is remo\ed or rubbed off This can influence the physician^'s use and control of the device.

$0028] In the past the industry has attempted to modify either hemostasia vake design (such as in various design found in patent documents US 6,776,774, 6,723,073, 6.702,255. 6,632,200, 5,807,350, and 5,782,§17) OJ the silicone elastomer materials b\ adding so- called solid lubricitv enhancing additives, including bismuth oxychloride, PI I-E powder, titanium dioxide, giaphitc, i ^ee for example US 5,562,632) Despite these attempts, none of hemostasis valves on the market proside constant performance and low friction forces f0029J As a preferred example of the improvements possible under this invention, the performance of hemostasis vahe as shovsn in US 6,632,200 and 6,551 ,283 can be impϊoved by incorporating the self-lubricating polymer composition at various parts A silicone elastomer is selected as well as liquid lubricants and or solid lubricant additives The liquid lubricants ha\ c lens surface energies compared to the silicone elastomer or blend selected and this better ensures the partial solubility and compatibility of the liquid lubricant into the matrix of the silicone elastomer By adjusting the lubricant used based upon the surface enejgy, an optimum release characteristic from the resulting euied polymer matrix and or a controllable release rate can be found For example, incorporating a solid lubricant or additional solid lubricant enhances the surface abrasive iesi stance, surface smoothness, and/or tear strength Frefeired liquid lubricants are polyfhioropolyethcr synthetic oils and hydrocarbon-based synthetic oils, while preferred solid lubricants a*e low molecular weight poh tetrafluoroetkylene powders, titanium dioxide, and baron nitrides Both the liquid and solid lubricants are preferably chemically inert, oid of chemical ieacthity foi the poK mes or blend and cuiing agent used, and ase preferably non-polar This prevents them from interfering in the curing process To increase the incorporation of a high or sufficient amount of synthetic oils or lubricants into the polymer matrix, a porous filler, such as porous silica, can optionally be added J0G30J Generally, the self-lubricating polymer compositions of .silicone elastomers contain 0 1 to 20 par (part i*ei Hundredth Resin by weight) liquid lubricants and/or (> to 20 phr solid lubricants, However, v arious preferred ranges of liquid aiid/or s,ofid lubricant concentrations can be selected for use, including 1-20 phr, 1 -5 phr, 3-5 phr. 3-6 phr, 4-6 phr, 3-10 phi. I- 10 phr, 1 -15 phi, 5- 15 phr, 8-10 phr. 10-20 phr, 15-20, and 5-10 phr, for example, can be used for either or both of the solid and liquid lubricant, alone or in combination By selecting a fluid-like lubricant that has similar surface energy to that of the cured silicone elastomer but is, chemical!) -inert, one of t>kiil in the art can be better assured that the lubricant can be effectively contained in the molecular pores of the cured matrix due to surface tension At the same time, the lubricants, do not interfere with the chemical reaction of curing Therefore, after curing, the fluid-like lubricant can be released under friction forces, preferably with continuous migration driven by the concentration gjadieut existing fiora the bulk materia! to the stuface |0031] The following are some examples, of the preferred self-lubricating polymers of silicone elastomers of the invention in which polyfluoropolyether (PFPE) or perfluoroalkyl ether synthetic oil (having surface energies of IS to 20 røΛVm or dy ne cm) aie used as liquid lubricants In addition or alternative!) , boion nitride oi low molecular weight polytetrafluoroethvlene (PTH-) mierofxmders may be used as solid lubricants to adjust anti -friction or abrasion resistance and/or tear strength

|0032] A preferred example of a medical device or part thereof to demonstrate the improved anti-fi ictioπ characteristics of the polymei compositions of the invention is a hemostasis \ ah e The val\ e may be reliably used with a wide variety of diameters for an inserting device, up to about 9 l^j (3 mm) catheters and down to guidewires of about 0 014 in (0 35 mm) A hollow tube can also be used, as in a molded 8 F introducer that can also be used as a catheter for various purposes 11 Iu strati v c Examples

[0033] Together with a mixture comprised of the appropriate tubing or gasket body materials, a combination of the silicone elastomer and lubricant, such as PFPH, is placed in a prev iously -heated mold and is then heated to a lemperatuic of about 130 to 200 degiees C , preferably at a molding clamping pressure of about 0 5 to 25 MPa, and preferably for a processing time of about 1 to 20 minutes, to obtain the finished product The silicone rubber or elastomer selected mav be one with a particular Durometer hardness (for example, the "Shore A scale" which, for {he μυiposes of this invention, includes similar or any comparable hardness scale for polymer compositions as known in the art). For example, anywhere between about 10 dυrometer to about ^LX) durometer can be used. The combined elastomer/lubricant polymers can then be evaluated on certain valve body designs having differing diameters. Insertion force measurements and leakage can then be conducted. An optimal polymer combination can tie thus selected for any particular combination of medical device parts or elements, such as a catheter and hemostasis valve, valves or gaskets and various introducers, such as steerable introducers or Svvartz introducers, and similar parts of functional parts of medical and biological devices.

Usually, the insertion force is desired to be low and no leakage present.

|G034] The components of the polymer composition can also be varied to optimize hardness, weight, and thickness, and one skilled in the art is familiar with selecting silicone elastomers, for example, that can result in a final product having a desirable or optimal ranges for any or all of these characteristics. In one embodiment, any of the Eiastosiϊ or

Silastic series of liquid silicone rubber can be selected The methyl vinyl silicone resin

Silastic Q7-4735 is used in the examples below, but many other resins can be selected and similarly used, as noted above, including Silastic Q7-4720

Example 1

|0035] A silicone elastomer resin based upon methyl vinyl silicone (Silastic Q7-4735) is selected as the polymer matrix. A liquid lubricant, PFPE synthetic oil, is used at 5 parts per hundred of rubber (phr). The components are mixed using a two-roller mill. The resulting compound is transfer-molded into the gaskets of a hemostasis vaKe, as noted above, and then post-cured at 150 degrees C for 2 hours

Example 2

|00361 The same polymer resin as Example I, but a liquid lubricant (PFPE synthetic oil) is used at 10 phr.

Example 3

J0037J The same polymer resin as Example S , but a solid lubricant {iov> molecular weight PTFE raieropowder) is used at 3 phr, and a liquid lubricant (PFPE, synthetic oil) is used at 5 phr.

Example 4 J0G38J The same poly mer jestn as Example I₁ but a solid Jυbiicant (low molecular weight PI Fh raicropυwder) is used at 8 phr. and a liquid lubricant (poly fiuoroaiLy iether synthetic oil) is used at S phr flxample 5

|ΘO39] The same polymei resin as Example i , but a solid lubricant (boion πitπde raicropowder) is used at 5 phr, and a liquid lubricant (polytluoroaikyietheϊ synthetic oil) is used at 10 phi Example 6

$0040] A thermoplastic silicone elastomei, Geniomer 200, is selected as the resin, a solid lubricant (low molecular weight PTFE micropowder) is used at 3 phr. and a liquid lubricant (polyOuoroalkyl ether synthetic oil) is used at 8 phr The ingredients are mixed into a seif-lubri eating polymer composition using a solvent or melt compound approach, as know-n in the ait The resulting comμoMtiυi! is then injection molded into a hemostasis gasket as noted above Example 7

[00411 The utility of the self-lubricating polymer compositions and the parts or elements made from them can be tested undei cyclic insertion conditions at constant forces I'nlike currently available products, the insertion forces aie \ ery stable at about 0 25 lbs during one hundred insertion cycles, even when five different {?F catheters axe used In comparison, the insertion forces vary from 0 I to 0 6 lbs during the parallel tests using cuπently av ailable materials

[0042] As shown iu Figure 4, the repeated insertion and withdrawal cycles of the self-lubricating polvmer of Lxample 1 show \ery little changes in forces measured o\er the 14 cycles Even when new catheters are used on the same hernostasis gasket, the forces remain constant fhus, the self-lυbπcatina polymers of the im entioπ allow a greatly improved consistency in the insertion and withdrawal processes Comparing to the Figure 5 jesuHs of a conventional polymer and heniostasis gasket, the forces vary over the entire period of the experiment and there is a dramatic and fairly constant increase in required foices at about cycle 10, presumably when the externally applied lubricant is nυ longei effective The reduction in friction forces can be demonstrated in a method that is illustrated in Figure J , in which a catheter is inserted into the blood vessel through an introducer that has a hemostasis value contained in its hub The lubricant releasing from the self-lubricating polymer composition of {he hernostasis valve effectively self-lubricates the contact surfaces between the catheter and hemostasis valve, leading to the reduction in the friction forces and/or substantially constant and predictable friction forces fO044] The reduction hi friction forces can be demonstrated in a method that is illustrated in Figure 1, in which a catheter is inserted into the blood vessel through an introducer that has a hemostasia value contained In its hub. The lubricant releasing from the self-lubricating polymer composition of the hemostasia vaive effectively self-lubricates the contact surfaces between the catheter and hemostasis valve, leading to the reduction in the friction forces and/or substantially constant and predictable friction forces. f0045J Although embodiments of this invention have been described above with a certain degree of particularity, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of this invention. All directional references (e.g , upper, lower, upward, downward, left, right, leftward, rightward, top, bottom, above, below, vertical, horizontal, clockwise, and counterclockwise) are only used for identification purposes to aid the reader's understanding of the present invention, and do not create limitations, particularly as to the position, orientation, or use of the invention Joinder references (e.g , attached, coupled, connected, and the like) are to be construed broadly and may include intermediate members between a connection of elements and relative movement between elements. As such, joinder references do not necessarily infer that two elements are directly connected and in fixed relation to each other. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not limiting. Changes in detail or structure may he made without departing from the spirit of the invention as defined in the appended claims.

Claims

What is claimed is:

i A biocompatible, self-lubricating polymer composition comprising a silicone elastomer and about 1 to about 20 parts per hundred by weight (phr) of a lubricity enhancing PFPE or hydrocarbon based synthetic oils,

2. The self-lubricating polymer composition of claim 1, wherein the silicone elastomer is selected from one or wore silicone resins having a dυrometer hardness from about 10 to about 90 on the Shore A scale.

3 The self-iubricating polymer composition of claim 1, wherein the PFPE synthetic oil is present at about 4 to about 20 phr.

4 The self-lubricating polymer composition of claim 2, wherein the PFPE synthetic oil is present at about 4 to about 20 phr

5 The self-lubricating polymer composition of claim I, wherein the PFPB synthetic oil is present at about 4 to about b phr

6. The self-lubricating polymer composition of claim 2, wherein the PFPE synthetic oil is present at about 4 to about 6 phr

7. The self-lubricating polymer composition of claim I, further comprising a biocompatible, solid lubricant roicrapowder.

8. The self-lubricating polymer composition of claim 1 , wherein the silicone elastomer is a methyl vinyl silicone elastomer and has a durometer hardness of about 30 to about 40 in the Shore A scale

9 The self-lubricating polymer composition of claim 8, wherein the PFPE synthetic oil is present at about 4 to about 6 phr

iθ. T he self-lubricating polymer composition of claim 8, further comprising a biocompatible, solid lubricant micropowder π . A medical oi' surgical device having a receiving area for inserting or withdrawing, the receiving area having a seal comprising a self-lubricating polymer composition, the polymer composition comprising a silicone elastomer and one or more of a biocompatible solid lubricant at about 0 1 to 20 phr and a biocompatible liquid lubricant at about 0. ϊ to 20 phr.

12. The medical or surgical device of claim i L wherein the silicone elastomer has a duromeier hardness from about 10 to about 90 on the Shore A scale

S 3. The medical or surgical device of claim 12. wherein the silicone elastomer is a methySvinyϊ silicone elastomer and has durometer hardness from about 20 to about 40 on the Shore A scale

14. The medical or surgical device of claim 11, wherein the polymer composition comprises PFPH synthetic oil

15. The medical or surgical device of claim 14, wherein the PFPE synthetic oil is present at about 4 to about 10 phr,

16. The medical or surgical device of claim !4, wherein the PFPE synthetic oil is present at about 4 to about 6 phr.

1 7. The medical or surgical device of claim ! 5, wherein the polymer composition contains no solid lubricant.

1 S. The medical or surgical device of claim 16, wherein the polymer composition contains no solid lubricant.

19. The medical or surgical device of claim U, wherein the polymer composition comprises a solid lubricant mieropowder at about 0 1 to 20 phr

20 A gasket or seal for a biomedical device comprising a self-lubricating polymer composition comprising a silicone elastomer and about 1 to about 20 parts per hundred by weight (phr) of a lubricity enhancing polyfluoropoivether fluid or hvdrocarbon-based synthetic oil

21. The gasket or seal of claim 20. wherein the silicone elastomer is selected from one or more silicone resins having a durometer hardness from about 10 to about 00 on the Shore A scale.

22. The gasket or seal of claim 20, wherein the silicone elastomer is a methylvinyi silicone elastomer and has a durometer hardness of about 20 to about 40 in the Shore A scale

23. The gasket or seal of claim 20, vv herein the lubricity enhancing oil comprises PFPE synthetic oil and where PFPE is present at about 4 to about 10 phr

24. The gasket or seal of claim 22, wherein the lubricity enhancing oil comprises PR³E synthetic oil and where PFPF, is present at about 4 to about 10 phr

25. The gasket or seal of claim 20, wherein the lubricity enhancing oil comprises PFPE synthetic oil and where PFPE is present at about 4 to about i0 phr.

26. The gasket or seal of claim 22, wherein the lubricity enhancing oil comprises PFPE synthetic oil and where PFPB is present at about 4 to about 10 phr

27 The gasket or seal of claim 20, further comprising a biocompatible, solid lubricant micropowder.

28. The gasket or seal of claim 22, further comprising a biocompatible, solid lubricant micropowder.

29. A method of producing a biocompatible self-lubricating polymer for use in a medical or surgical device, comprising mixing a silicone elastomer or silicone elastomer blend having a durometer hardness of about IO to about 90 on the Shore A scale with one or more liquid lubricants having a surface energy of about 10 to about 20 dyne/cm, and setting the mixture into a desired shape or mold for a selected medical or surgical device of part thereof.

30. The method of claim 29. wherein the liquid lubricant is PFPE synthetic oil and PFPB is present at about 4 to about 10 phr.

31. The method of claim 29_: wherein the liquid lubricant is PFPE synthetic oi! and PFPE is present at about 4 to about 6 phr

32. The method of claim 29, wherein the silicone elastomer is a methylviny! silicone elastomer and has a durometer hardness of about 30 to about 40 on the Shore A scale.

33 The method of claim 29_; wherein the medical or surgical device is a tube having an outside diameter from about 5 mm to about 2 mm and an inside diameter of about 3 5 mm to about ! .5 mm,

34. The method of claim 29. wherein the medical or surgical device is an introducer.

35. The method of claim 29, wherein the medical or surgical device is a hemostasis valve.

36. The method of claim 29, further comprising adding a biocompatible, solid lubricant micropowder to the mixture of silicone elastomer or blend and one or more liquid lubricants.

37. The method of claim 29, wherein the polymer is used in the production of a receiving area for medical or surgical device or part thereof

38. The method of claim 26. wherein the receiving area for medical or surgical device or part thereof is formed into a dynamic seal.

39. The method of claim 29, wherein the receiving area for medical or surgical device or part thereof is formed into a semidynamic seal.

40. The method of claim 29, wherein the medical or surgical device is a catheter.

41 The method of claim 29, wherein the polymer is used in the production of a sheath, tube or tubing, whereby the tube, sheath or tubing comprises at least about 10% or more of the self-lubricating polymer over its insertion length or receiving length

42. A medical or surgical device made from the method of claim 37

43. A medical or surgical device incorporating a sheath, tube or tubing made from the method of claim 41.

44. A biocompatible self-lubricating polymer composition comprising a silicone elastomer and about 1 to about 20 phr of a biocompatible lubricant composition comprising one or more of a polyfluoropoiyether synthetic oil, a polytetrafluoroethyiene synthetic oil. a hydrocarbon-based synthetic oil, a low molecular weight polytetrafluoroethyiene powder, a titanium dioxide micropowder, a molybdenum disulfide micropo^der, a graphite micropowder, a baron nitride micropowder, or a porous micropowder.

45. The self-lubricating polymer composition of claim 44, wherein the silicone elastomer is .selected from one or more silicone resins having a durorneter hardness from about 10 to about 90 on the Shore A scale.

46. The self-lubricating polymer composition of claim 44, wherein the lubricant composition comprises PFPE synthetic oil.

47. The self-lubricating polymer composition of claim 46, wherein PFPE is present at about 4 to about 10 phr

48 The self-iubricating polymer composition of claim 47, wherein the PFPK synthetic oil is present at about 4 to about 6 phr.

49. The self-lubricating polymer composition of claim 44, wherein the lubricant composition consists essentially of PFPB synthetic oil.

50. The self-lubricating polymer composition of claim 49, wherein the PFPE synthetic oil is present at about 1 to about i0 phr

51. The self-lubricating polymer composition of claim 50, wherein the PFPE. is present at about 4 to 10 phr.

52. The self-lubricating polymer composition of claim 44, wherein the silicone elastomer is a thermosetting or thermoplastic silicone elastomer.

53. The self-lubricating polymer composition of claim 52, wherein the silicone elastomer is a methylvinyl silicone elastomer,

54. The self-lubricating polymer composition of claim 46, wherein the silicone elastomer is a methylvinyl silicone elastomer.

55. The self-lubricating polymer composition of claim 49, wherein the silicone elastomer is a methylvinyl silicone elastomer.

56. The self-lubricating polymer composition of claim 50, wherein the silicone elastomer is a methylvinyl silicone elastomer.