AU660958B2 - Rubber gloves, their manufacture and use - Google Patents

Description

OPI DATE 07/09/92 AOJP DATE 15/10/92 APPLN. TD 11866 q2 PCT NUMBER PCT/GB92/00171a INTEL. .ON TREATY (PCT) (51) International Patent Classification 5 (11) International Publication Number: WO 92/13497 A61B 19/04 Al (43) International Publication Date: 20 August 1992 (20.08.92) (21) International Application Number: PCT/GB92/00171 (74)Agent: HOBBS, John, David; Corporate Patents Trade Mark Department, Smith Nephew pci, Gilston Park, (22) International Filing Date: 29 January 1992 (29.01.92) Harlow, Essex CM20 2RQ (GB).

Priority data: (81) Designated States: AT (European patent), AU, BE (Euro- 9102070.1 31 January 1991 (31.01.91) GB pean patent), CA, CH (European patent), DE (Euro- 9103320.9 16 February 1991 (16.02.91) GB pean patent), DK (European patent), ES (European pa- 9108263.6 17 April 1991 (17.04.91) GB tent), FI, FR (European patent), GB (European patent), GR (European patent), IT (European patent), JP, LU (European patent), MC (European patent), NL (Euro- (71) Applicant (for all designated States except US): SMITH pean patent), NO, SE (European patent), US.

NEPHEW PLC [GB/GB]; 2 Temple Place, Victoria Embankment, London WC2R 3BP (GB).

Published (72) Inventors; and With international search report.

Inventors/Applicants (for US only) TARBY, Mark, Alan [US/US]; 5569 Beverly Avenue, North Canton, OH 44721 FARRAR, David [GB/GB]; 59 Tylney Croft, Harlow, Essex CM19 4LT 66 0 9 5 8 (54)Title: RUBBER GLOVES, THEIR MANUFACTURE AND USE (57) Abstract A medical glove which may be donned by a dry or damp hand comprises a microtextured medical glove, provided on its inside surface with a surfactant and/or silicone. The microtextured glove is preferably a chlorinated medical glove which has been treated with polydimethyl siloxane hexyldecyl pyridinium or sodium lauryl sulphate, or a mixture of two of these materials.

WO 92/13497 PCT/GB92/00171 RUBBER GLOVES, THEIR MANUFACTURE AND USE Background to the Invention Medical personnel such as doctors, nurses, paramedics and the like and especially surgeons, frequently use natural rubber gloves to protect their patients and themselves from potential bacteriological or viral contamination. Gloves of this type will be referred to herein as "medical gloves" for the sake of convenience.

A long standing problem with medical gloves is that they can be difficult to don. In order to mitigate this difficulty it has been a long standing practice to powder the gloves so that the hand slips more easily into the glove. -However, a number of medical authorities and a number of glove users are dissatisfied with the use of powder as a donning aid.

This dissatisfaction stems from practical difficulties such as the occasional need to remove excess powder after donning and from concerns that some powders could lead to granulomas in some circumstances.

In order to provide medical gloves that could be easily donned without recourse to powder the art has provided two main and very different types of solution.

WO 92/13497 2 PCT/GB92/00171 The first solution is to employ a natural rubber that has been treated with chlorine so that the medical glove is more easily donned. The alternative solution is to bond a layer of synthetic polymer to the inside (that is wearer contacting surface) of the medical glove and thereby render it more easily donned.

Examples of chlorinated medical gloves are given in US Patent No. 4304008 and examples of providing a layer of synthetic polymer on medical gloves are given in US Patents Nos. 3813695, 4482577, 4499154, 4548844, 4575476, 3856561, 3919442, 3967014, 4027060, 4082862, 3286011 and 3411982.

It can be difficult and expensive to provide medical gloves that employ a layer of synthetic polymer thatis well bonded to the natural. rubber and is sufficiently lubricious to dispense with the need for powders. The provision of such layers also tends to require the use of organic solvents with their associated hazards.

Chlorinated medical gloves can be manufactured without the use of organic solvents and have found widespread use. Unfortunately such gloves are only easily donned if the hands are dry and many users (in particular many surgeons) have damp hands at the point WO 92/13497 3 PCT/GB92/00171 where they will don the gloves (for example, a surgeon's hands will still be damp following having scrubbed with an antibacterial agent). This severely limits the use of chlorinated medical gloves.

It is an object of the present invention to provide a medical glove that avoids the need to employ an inside layer of synthetic polymer over the natural rubber but which is still readily donable by the dry or damp hand without the recourse to powders.

Summary of the Invention The present invention provides a medical glove that is readily donable by the dry or damp hand without requiring an inside layer of synthetic polymer or a powder. The medical glove according to the present invention comprises a microtextured-medical glove provided on the inside surface with one or both of a surfactant or a silicone. When used herein the term microtextured means that the clove surface has been roughened, for example by treatment with halogen or an acid (see for example "Surface Treatment of Rubber to Reduce Friction" by A D Roberts and C A Brackley in J Nat Rubb Res 1-21).

Detailed Description of the Invention The present invention provides a medical glove WO 92/13497 4 PCT/GB92/00171 which may be donned by the dry or damp hand which comprises a microtextured medical glove the inside surface of which is provided with one or both of a surfactant or a silicone.

The microtextured glove may be microtextured on the inside only or on both the inside and the outside.

The microtextured medical gloves for use in the invention may be obtained by treating the surface of a glove by halogenation, or an acid (especially an oxidising acid). Most suitably the microtextured medical glove is a halogenated medical glove.

Preferably the microtextured medical glove is a chlorinated medical glove.

-One of.the advantages of .employing chlorinated medical gloves is that they will be familiar to many users as a number of excellent commercial chlorinated gloves are already available such as Ansell's Powder Free, Sensotech G204 from LRC and Pristine from Fuji Latex and Perry Style 47 from Smith Nephew Perry.

(These commercially available gloves have good dry hand donning properties but of course lack the desirable damp hand donning properties of the gloves of the present invention).

WO 92/13497 5 PCT/GB92/00171 The gloves of the present invention are most suitably surgeons gloves.

From the foregoing it will be appreciated that in a preferred aspect the present invention provides a medical glove which may be donned by the dry or damp hand which comprises a chlorinated medical glove the inside surface of which is provided with one or both of a surfactant or a silicone.

The surfactant employed may be any suitable surfactant for use on the skin, that is a skin compatible surfactant. Such surfactants may be ionic or non-ionic. Mixtures of surfactants that is mixtures containing more than one surfactant, for example, two surfactants may be.used if.desir.ed.

Suitable ionic surfactants include cationic, anionic and amphoteric (zwiterionic) surfactants.

Suitable cationic surfactants include alkyl, alkenyl, aralkyl and aryl group containing surfactants containing at least one liphophilic moiety (for example one of said group of for example 8 to 18 carbon atoms) and a salted nitrogen atom, for example such as a salted trialkylamine group, piperidinum group or the WO 92/13497 6 PCT/GB92/00171 like. Any counter ion present will be skin compatible such as a halide, for example chloride. Particularly suitable cationic surfactants include alkyl and alkenyl pyridinium compounds, for example those wherein the liphophilic moiety has from 12 to 18 carbon atoms.

Preferred cationic surfactants include cetyl pyridinium chloride (also called hexadecyl pyridinium chloride).

Suitable anionic surfactants include alkyl, alkenyl, aralkyl and aryl group containing surfactants containing at least one liphophilic moiety (for example one of said group of for example 8 to 18 carbon atoms) and a salted acid group, for example a carboxylic, sulphonic, sulphuric, phosphoric, phosphonic or like acid group. Any counter ion present will be skin compatible, for example an alkali metal ion such as sodium or potassium of which sodium is preferred.

Particularly suitable anionic surfactants include alkyl and alkenyl sulphates, for example those wherein the lipophilic moiety has from 12 to 18 carbon atoms.

Preferred anionic surfactants include sodium lauryl sulphate.

Suitable amphoteric surfactants include those containing the above described cationic and anionic groups.

WO 92/13497 7 PCT/GB92/00171 Suitable non-ionic surfactants include those containing residues of ethylene oxide, for example polyethoxylated fatty alcohols, polymers of ethylene oxide and copolymers of ethylene oxide and propylene oxide.

Suitable polyethoxylated fatty acids include those where an alkyl, alkelyl group of 8 to 18 carbon atoms or a sorbitan or similar group carry from 1 to usually 2 to 8 polyoxyethylene residues wherein the polyoxyethylene residue has about 15 to 80 oxyethylene groups. Such materials are available commercially under trade marks such as TWEEN, BRIJ, SPAN, GENEROL and TERGITOL, MYRJ, ANTAROX and TRITON. TWEEN (polyoxyethylene sorbitan esters of fatty acids such as laurate, palmitate, sterate, oleate) and ANTAROX (nonylphenol ethoxylates) are of particular interest.

Suitable polymers of ethylene oxide and propylene oxide are generally block copolymers and are also commercially available, for example under such trade marks as PLURONIC, TERGITOL, BRIJ and GENEROL.

A class of surfactants which can be used which are ionic but also employ polyethylene oxide are those in which the ionic moieties are joined to the lipophilic moieties by polyoxyethylene moieties.

WO 92/13497 8 PC/GB92/00171 A preferred surfactant is a hexadecylpyridinium chloride. A preferred mixture of surfactants contains a hexadecylpyridinium chloride and sodium lauryl sulphate.

The silicone employed may be any polysiloxane or the like skin compatible silicone. Preferably the silicone is a liquid silicone. Apt silicones include polysiloxanes such as polydimethylsiloxane and analogous compounds in which some of the methyl residues are replaced by other functions such as the alkyl, aryl, aralkyl, alkenyl, alkoxy and the like.

Alternatively the polysiloxane may be terminated by a non-siloxane moiety such as polyethyleneoxide dimethylsilyl, aminoethyldimethylsilyl, hydroxyethyldimethylsilyl,--hydr-oxyethyldimethylsilyl or the like.

Preferably the polysiloxane employed is polydimethylsiloxane.

Although the surfactant and the silicone may be used separately, it is most apt to employ the surfactant and it is preferred to use them both.

From the foregoing it will be realised that in a WO 92/13497 9 PCT/GB92/00171 particularly preferred aspect this invention provides a surgeons glove that may be donned by the dry or damp hand which comprises a chlorinated surgeons glove the inner surface of which is provided with cetyl pyridinium chloride and sodium lauryl sulphate.

The amount of surfactant and/or silicone present on the inner surface of the glove may be any that is sufficient to aid damp hand donning but is typically very l.ow, for example it is not necessary to leave a readily visible deposit on the surface (although if it is desired to leave a readily visible amount this may be done).

Aptly the amount of surfactant and/or silicone on the surface is that which can be deposited from an aqueous-system solution and/or emulsion containing at least 0.1% w/w of surfactant and/or at least 0.05% w/w of a silicone. The aqueous system would not generally contain more than about 10% w/w of surfactant and/or more 2.5% by weight of a silicone, at a non-extreme temperature (for example 5 50 0 C, more usually 10 0 C, favourably 15 30 0 C, for example at 20 0 C) for a period of at least 1 minute. Generally the deposition takes place over a period of not more than 30 minutes, for example 5 to 20 minutes. An example of a suitable aqueous system contains about 0.1 to 10% w/w of WO 92/13497 10 PCT/GB92/00171 surfactant and 0.01 to 2.5% w/w of siloxane.

A particularly appropriate method of applying the surfactant and/or silicone is given in the examples hereto.

Most aptly a surfactant and/or a silicone is applied to both surfaces of the medical glove.

The gloves of this invention may be manufactured by treating their inside surface with a surfactant and/or silicone. The treatment may also coat the outside surface of the glove if desired.

Normally the surfactant and/or silicone will be used in aqueous solution and/or emulsion.

The concentrations, temperatures and times may be as hereinbefore mentioned.

A suitable method for treating the inside and/or outside of the microtextured glove at the same time is to tumble the microtextured glove in the coating liquid and then to dry the glove, for example in a tumble dryer.

The treatment with surfactant and/or silicone can WO 92/13497 11 PC/GB92/00171 be carried out on a glove immediately after microtexturing or later. Thus, for example, a glove can be chlorinated in conventional manner in a chlorine bath, optionally rinsed, and then immersed in a bath of surfactant and/or silicone and thereafter dried.

Microtexturing may be introduced by physical or chemical means. A suitable physical means is to mould the rubber surface, for example by depositing the rubber latex onto a former which is pattened. Suitable chemical means include etching, treatment with a halogenating agent an acid or the like.

The microtexturing cannot be seen with the eye as individual raised or depressed areas. However in some cases a haz'.ess can be seen. The spacing between adjacent raised areas will aptly be less than 100 microns, most aptly will be less than to microns and preferably will be less than 30 microns. The spacing between adjacent raised areas will aptly be greater than 0.5 microns, most aptly will be greater than 1 micron and preferably will be greater than 1.5 microns.

A particularly favoured method of producing a microtextured surface where the spacing between adjacent raised areas is 1 to 10 microns and most aptly 2 to 6 microns is treatment with a chlorinating agent.

WO 92/13497 12 PCIT/GB92/00171 A particularly favoured method of producing a microtextured surface where the spacing between adjacent raised area is to 1 to 10 microns and most aptly 2 to 6 microns is treatment with a chlorinating agent.

A particularly favoured method of producing a microtextured surface where the spacing between adjacent raised areas is 10 to 100 microns, most aptly to 50 microns and favourably 20 to 30 microns is to form the rubber on a former processing the mirror image of the desired microtexture.

The inner surface of the glove may employ two types of microtexturing, for example that produced by physical means such as moulding and also (ii) that produced by chemical means such as treatment with a halogenating agent, for example chlorination. It is preferred to employ two types of micro.exturing since the wet donning performance of the glove is generaA'v better than if only one type of microtexturing is employed.

The glove may also have a macrotexturing on its inner surface. Such macrotexturing is often readily visible to the eye. The spacing between raised areas WO 92/13497 13 PC/GB92/00171 will aptly be more than 100 microns, more aptly more than 200 microns, most aptly more than 450 microns, for example about 500 to 1000 micron- A spacing of about 800 microns has been found to be particularly suitable.

Macrotexturing may be produced by physical means such as by forming on a former which is provided with the mirror image of the macrotexturing sought.

The depth of the macrotexturing ("average peak to tough height") will generally be about 1 to about 100 microns. Aptly the depth of the macrotexturing will be greater than 2 microns, more aptly greater than 4 microns, most aptly greater than 10 microns. Aptly the depth of the macrotexturing will be less than microns, more aptly less than 50 microns and most aptly less than 35 microns. A preferred depth of macrotexturing is about 20 to 30 microns, for example about 25 microns.

It is preferred to employ macrotexturing and microtexturing since the wet donning performance is particularly enhanced in such circumstances.

The glove formers required to give texturing of the type referred to herein are well known in the art because hitherto such formers have been employed to provide a roughened outer surface to the glove. In the present invention what is traditionally the outer WO 92/13497 14 PCT/GB92/00171 surface of the glove becomes the inner surface in use (that is the glove is inverted and the normally outside surface is next to the skin). The formers can be made by sand blasting porcelain formers, spattering formers with glaze or just by using appropriate unglazed porcelain formers. The use of unglazed porcelain formers (which has the typical feel of unglazed porcelain) have lead to particularly suitable gloves of this inventions when chlorinated and treated with surfactant on the donning (inner) surface.

US Patents Nos. 4597108, 4851266, 3992221, 3740262 and 3637411 and European Patent Application No.

88119875 may be read for methods of halogenating gloves.

Gloves may be chlorinated by immersion in a chlorination bath. This can be done in a manner which chlorinates both surfaces or the hand contacting surface only. If both surfaces are to be chlorinated gloves can be maintained open in the bath. If only the hand contacting surface is required to be chlorinated the glove can be on a former and thereafter inverted or can have its opening closed or be maintained flat and thereafter inverted.

The gloves can be maintained in the chlorination WO 92/13497 15 PCT/GB92/00171 bath for any convenient time, for example from about seconds to 2 hours, but are more usually in the chlorination bath for from about one minute to one hour, more aptly more than one minute, most aptly more than 5 minutes and preferably more than 8 minutes, and more aptly for less than 20 minutes, most aptly less than 15 minutes and preferably less than 12 minutes.

Chlorination may be effected in any convenient manner but one particularly apt method is by dipping in a bath of water containing one part by weight of concentrated hydrochloric acid and 6 parts by weight of sodium hypochlorite solution available Cl). The gloves may be immersed in the chlorination bath for a range of times, for example 1, 5, 10 20 and 30 minutes.

The sides that form the outsides of the gloves in the chlorine bath formed the insides (as worn) of the gloves. After chlorination the gloves may be dried in an oven at 70°C for 30 minutes or at any other convenient temperature and time.

The insides (as worn) of the gloves may be treated with a surfactant and silicone mixture in water. The mixture may consist (by weight) of 2% cetylpyridinium chloride (CPC) and 0.5% DC 365. The gloves may be treated by holding them open and then filing them with the surfactant/silicone mixture and WO 92/13497 16 PCT/GB92/00171 then emptying them again. The gloves can be then dried at 70 0 C for 30 minutes or at any other convenient temperature and time.

The gloves produced in such a manner may be donned using damp hands.

The wet donning performances of such gloves in the abeence of CPC/silicone treatment, seem to show an optimum at between 5 and 10 minutes chlorination. The use of the CPC/silicone treatment improves the performance of such gloves; the optimum chlorination time seeming to lie between 10 and 30 minutes.

SEM study has revealed changes in latex texture according to dwell time in the chlorine bath. A fine texture, similar to that of a cauliflower floret was seen throughout. Between 1 and 10 minutes chlorination one can see that furrows are being gradually etched into the latex, leading to a crazed appearance; while the non-furrowed areas tend to retain their cauliflower floret appearance.

Slippery latex surfaces are desirable on the inside (as worn) of gloves as they aid donning.

However, on the outside of gloves an excessively slippery surface is undesirable as it may make the WO 92/13497 17 PCT/GB92/00171 holding of instruments difficult. As increasing the degree of chlorination makes surfaces more slippery differential chlorination between the inside and outside surfaces (as worn) can be advantageous.

Gloves may be made on unglazed porcelain formers.

The gloves may then be chlorinated by allowing the side that formed the inside (as worn) be the outside of a glove as placed into a chlorine bath between 1 and 30, for example for 10 minutes. The gloves may then be removed, drained and inverted before being placed back into the chlorine bath for a further 1 minute when both surfaces were chlorinated. After chlorinaticn the gloves may be dried at 70 0 C for minutes or any convenient temperature and time.

The gloves may then have CPC/silicone applied to the inside (as worn) surface only by filling the glove with the solution of the two agents.

The most advantageous gloves of this invention are sterile surgeon's gloves. Such gloves are most aptly distributed in bacteria-proof packaging to maintain sterility. Most aptly the packaging is of paper or plastic film. Favourably the packaging is in the form of a peel-apart container such as a pouch.

WO 92/13497 18 PCT/GB92/00171 Thus in a highly preferred aspect the present invention provides a surgeon's glove of the invention as hereinbefore described which is a sterile glove within a backeria-proof peel-apart pouch.

The sterile glove of this invention may be sterilised in convenient manner, for example by treatment with ethylene oxide or ionizing radiation such as gamma irradiation. Methods of sterilizing gloves are very well known in the art.

The following examples illustrate the invention.

Example 1 Size 7.5 "Ansell No Powder" gloves (chlorinated on both surfaces) were placed in a bath having the following composition.

ml Distilled water Hexadecylpyridium chloride Dow Corning 365 Medical Grade Silicone Emulsion 960.5 20 S 2% The gloves were left for 15 minutes at room WO 92/13497 19 PCT/GB92/00171 temperature. They were then dried at 70 0 C f-r minutes, being reversed after 15 minutes to totally dry the inside. When dry they were reversed again back to their original orientation.

Example 2 Example 1 was repeated omitting the hexadecylpyridinium chloride.

Example 3 Example 1 was repeated omitting the silicone.

Example 4 Example 1 was repeated coating the inner surface only.

Example The glove of Example 1 was placed in a pouch with a peel-apart closure and the pouch closed. The glove and pouch were sterilized by treatment with ethylene oxide in conventional manner.

WO 92/13497 20 PCT/GB92/00171 Example 6 Preparation of Basic Glove A glove was formed on an unglazed porcelain former in conventional manner by dipping the former into a calcium ion coagulant and then into a wax free natural rubber latex, drying, leaching in water and curing. The glove was powdered on the outside with starch to prevent adhesion until after chlorination.

Chlorination A glove prepared as described in was placed in a chlorine bath which comprises a solution in water (465g) of concentrated hydrochloric acid and sodium hypochlorite solution (30g, The glove was tumbled in the bath for 10 minutes at room temperature (approximately 20 0 The glove was removed from the solution and washed with water and thereafter dried at 70 0 C for minutes. About two thirds through the drying procedure the glove was inverted to ensure both surfaces were dry. The glove was inverted again so that the roughened side was on the outside.

Slip Treatment The glove then was immersed in a bath containing WO 92/13497 21 PCT/GB92/00171 water (100g) in which was cetylpyridinium chloride (2g) and a silicone, Dow Corning 365 1.42g) so that both sides were treated.

The treated glove was dried at 70 0 C for minutes being inverted about mid way through to ensure both surfaces were dry. At the end of this process the roughened and slip treated side is on the inside as worn.

Example 7 A glove made as in Example 6(a) was tumbled in a chlorine bath as described in Example 6(b) for ten minutes. The glove was replaced in the bath and tumbled for a further one minute. The glove was removed, washed with water and thereafter dried at 70 0

C

for 30 minutes. About two thirds through the drying procedure the glove was inverted to ensure both surfaces were dry. With the roughened side on the inside the inside only was treated with a solution as described in Example The solution was emptied from the glove and the glove dried at 70 0 C for thirty minutes inverting twice during the procedure to dry thoroughly and to place thr roughened side on the inside of the glove.

WO 92/13497 22 PCr/GB92/00171 Example 8 Size 7.5 Perry Style 47 gloves (chlorinated on both surfaces) marketed by Smith Nephew Perry, were sprayed on the inside surface with a solution having the following composition: Distilled water 960ml Hexadecylpryidinium chloride 20g M 2% Sodium Lauryl Sulfate 20g 2% The gloves were dried for 30 minutes. When dried they were reversed again back to their original orientation.

When tested the glove of the invention was significantly easier to don by the damp hand.

Example 9 Example 5 was repeated omitting the hexadecylpyridinium chloride.

Claims (19)

1. A medical glove which may be donned by a dry or damp hand which comprises a microtextured medical glove having an inside surface and an outside surface wherein said inside surface is directly provided with one or both of a surfactant and a silicone.

2. A glove as claimed in claim 1 in which the microtextured medical glove is a chlorinated medical glove.

3. A glove as claimed in either of claims 1 or 2 in which the inside surface of the glove is provided with a surfactant.

4. A glove as claimed in either of claims 1 or 2 in which the inside surface of the glove is provided with a mixture containing more than one surfactant.

A glove as claimed in either of claims 1 or 2 in which the inside surface of the glove is provided with a silicone.

6. A glove as claimed in either of claims 1 or 2 in which the inside surface of the glove is provided with a surfactant and a silicone. 1 I i, r r r 1 ,r r, r ui r cc r ri r c' i; ric/ i P i r r t I: l.c\ 95G419,p:oper\m1a, 11866-92-109. 2 3 -24-

7. A glove as claimed in any one of claims 1 to 4 or 6 in which the surfactant is cationic surfactant containing a salted nitrogen atom.

8. A glove as claimed in claim 7 in which the surfactant is hexyldecyl pyridinium chloride.

9. A glove as claimed in any one of claims 1 to 4 or 6 in which the surfactant is an anionic surfactant containing a salted acid group.

10. A glove as claimed in claim 8 in which the surfactant is sodium lauryl sulphate.

11. A glove as claimed in claim 4 in which the mixture contains hexyldecyl pyridinium and sodium lauryl sulphate.

12. A glove as claimed in any one of claims 1, 2, 5 or 6 in which the siloxane is polydimethyl siloxane.

13. A glove as claimed in claim 6 in which the silicone is polydimethyl siloxane and the surfactant is hexyldecyl pyridinium chloride.

14. A glove as claimed in any one of claims 1 to 13 which has been microtextured by means of a moulding process. 25

15. A sterile glove as claimed in any one of claims 1 to 14 within a bacteria proof pack.

16. A method of making a glove as claimed in any one of claims 1 to 14 which comprises treating the inside surface of microtextured glove with one or both of a surfactant and a silicone.

17. A method as claimed in claim 16 which comprises treating the glove with an *4* I ;V2 I,. 931007,p:\operee,11866smLspe,24 aqueous solution of hexyldecyl pyridinium chloride and sodium lauryl sulphate.

18. A glove as claimed in claim 1 substantially as hereinbefore described with reference to any one of the Examples.

19. A method as claimed in claim 16 substantially as hereinbefore described with reference to any one of the Examples. DATED this 7th day of October, 1993. SMITH NEPHEW PLC By Its Patent Attorneys DAVIES COLLISON CAVE 931007,p:\oper\e 66 a <et ft fr~ t a IO 4f« *307p\oe~e 116sise2 INTERNATIONAL SEARCH REPORT Ilwttistonal Application No PCT/GB 92/00171 I. CLASSIFICATION OF SUBIJECT MATTER (if several classifltatlon symbols apply, Indicate alI)6 Accnrding to international Patent Classification (1PQC or to both National Classification and IPC Int..Cl. 5 A61B19/04 HI. FIELDS SEARCHED Minimum Documentation SeaLrched7 Classification System Classification Symbhols Int.Cl. 5 A618 Documentation Searched other than Minimum Documentation to the Extent that such Documents are Included in the Fields Searchedl Ml. DOCUMENTS CONSIDERED TO BE RELEVANT9 Category Citation of Document, L 1 with indication, where appropriate, of the relcvant passages 12 fRelevant to Claim No.' X WO,A,8 400 908 (LRC) 15 March 1984 1,3, 5-10, 12-16 see page 5 page 6 X WO,A,8 100 346 (AMERICAL HOSPITAL SUPPLY) 19 1-3,5,6, February 1981 12-16 see page 8, line 1 see page 6, line 1 line 4 X EP,A,0 328 421 (COLUMBIA UNIVERSITY) 16 August 1,5,12, 1989 15,16 see abstract A US,A,4 329 312 (GANZ) 11 May 1982 14 see abstract A GB,A,1 343 411 (ETHICON) 10 January 1974 see claim 1 Special categories of cited documents :1 T' later document published after the international filing date A doumet dfinng he eneal sareof he rt hic isnotor priority date and not in conflict with the application but ''dcnside t e b ealsae of particularirelesance cited to understand the principle or theory underlying the consderd toe o paricuar rlevnceinvention 'E ealifer document but published on or after the international X' document of particular relevance; the claimed invention filing date cannot he considered novel or cannot be considered to LV document which may throw doubts on priority claim(s) or involve an inventive step which Is cited to establish the publication date of another document of particular relevance; the claimed Invention citation or other special reason (as specified) cannot be considered to involve an inventive step when the ~0 APRILen 19ern92a rldsloue sehbto rdoueti obndwt neo oeohrsc ou International Searching Authority EUROPEAN PATENT OFFICE Ftna PCT/5SA/2iO tscmd &kd (Jmay 192S) PCT/GB 92/00171 International Application No Ml. DOCUMENTS CONSIDERED TO lBE RELEVANT (CONTINUED FROM THE SECOND SHET) Category Citation of Document, with Indication, where appropriate, of the relevant passages Relevnt to (32.im No. J NAT RUBB RES vol. 4, no. 1, pages 1 21; ROBERTS AND BRACKLEY: 'Surface treatment of rubber to reduce friction' cited in the application see the whole document 1 1,6,7, 12,14,16 FR,A,2 240 700 (DOW CORNING) WO,A,9 105 557 (BIORESEARCH) 14 March 1975 2 May 1991 see abstract Form P CTIISA/210 jemrs f I~i IJrnary 19"S ANNEX TO THE INTERNATIONAL SEARCH REPORT ON INTERNATIONAL PATENT APPLICATION NO. GB 9200171 SA 55757 This annex lists the patent family members relating to the patent documents cited in the above-mentioned international search report. The members are as contained in the European Patent Office EDP file on The European Patent Office is in no way liable for these particulars which are merely given for the purpose of information. 02/04/92 Patent document Publication Patent family Publication cited in search report date member(s) date WO-A-8400908 15-03-84 AU-B- 570646 24-03-88 AU-A- 1949483 29-03-84 AU-B- 598061 14-06-90 AU-A- 8126887 10-03-88 CA-A- 1225508 18-08-87 DE-A- 3378527 29-12-88 EP-A,B 0105613 18-04-84 EP-A- 0198514 22-10-86 EP-A- 0199318 29-10-86 US-A- 4499154 12-02-85 US-A- 4575476 11-03-86 US-A- 4548844 22-10-85 WO-A-8100346 19-02-81 US-A- 4310928 19-01-82 BE-A- 884554 17-11-80 EP-A- 0032507 29-07-81 EP-A-0328421 16-08-89 US-A- 5019096 28-05-91 AU-A- 2989589 17-08-89 JP-A- 2017071 22-01-90 AU-A- 7922991 03-10-91 US-A-4329312 11-05-82 DE-A- 2056489 27-05-71 FR-A- 2069450 03-09-71 GB-A- 1326102 08-08-73 NL-A- 7016313 18-05-71 GB-A-1343411 10-01-74 None FR-A-2240700 14-03-75 US-A- 3872515 25-03-75 AU-A- 7040774 08-01-76 BE-A- 818893 14-02-75 CA-A- 1035501 01-08-78 DE-A- 2439134 03-04-75 GB-A- 1421100 14-01-76 JP-A- 50049039 01-05-75 SE-B- 404872 06-11-78 SE-A- 7410421 18-02-75 WO-A-9105657 02-05-91 US-A- 5069965 03-12-91 SFor more details about this annex see Official Journal of the European Patent Office, No. 12/82 ANNEX TO THE INTERNATIONAL SEARCH REPORT ON INTERNATIONAL PATENT APPLICATION No. GB SA 9200171 55757 This annex lists the patent family members relating to the patent documents cited in the above-mentioned international search report. The members ame as contained in the European Patent Office EDP file on Ile European Patent Office is in no way liable for these particulars which are merely given for the purpose of information. 02/04/92 Page 2 Patent documeaA Publication Patent family Publication cited in search reort dat member(s) dat WO-A-9105657 AU-A- 6715590 16-05-91 EP-A- 0448703 02-10-91 w For more details about this annex :see Offiial Journal of the European Patent Office, No. 12/S2