MXPA98010584A - Med device - Google Patents

Abstract

A method is described for fabricating a medical device having an extended handle of hydrophilic coated surface for insertion into body conduits, comprising the steps of having the extended handle formed of a thermoplastic elastomer material selected from the group consisting of an amide of polyether block and a styrene block copolymer and forming the hydrophilic coating of the handle extended by the sequential application to the surface of the extended handle of a solution comprising between 0.05 to 40% (weight by volume) of an isocyanate compound and a solution which contains between 0.5% and 50% (weight for volume) of polyvinylpyrrolidone and cure at elevated temperature

Description

MEDICAL DEVICE Field of Invention The present invention relates to medical devices having an extended handle, having a covered outer surface for insertion into a conduit in a human or animal body and primarily, but not exclusively, concerned with surface-coated catheters.

Background of the Invention Many medical devices incorporate extended handles such as tubes that are projected for insertion into and around the ducts of a living body, such as those of the urethral tract and the cardiovascular system. The most common type of these general groupings of medical devices are known as catheters. Incubating catheters include those designated for urological, angioplastic and valoplastic uses, that is, adapted for insertion into the REF .: 29061 urethra, the opening of a blood vessel and ducts of the heart of a living body, usually a human body.

Due to the projected uses of said medical device, certain parameters need to be satisfied by the material so that the extended handle is manufactured. The material that most meets the requirements is smooth, with good resistance to twisting, good dimensional stability, processability, for example easy to form and stick, and the possibility to be sterilized by radiation, heat, ethylene oxide or other means. The need for a material to accept a treatment surface that gives desired surface properties to the medical device such as lubrication, hydrophilic affinity and compatibility with the blood is additional. For this finally, the chemistry of the substrate material is critical since this affects the possibility of covering the substrate.

For many years the now polyvinyl chloride (PVC) was used for the manufacture of medical devices of extended handle to insert them in a body conduit such as catheters because the PVC met the requirements mentioned in the preceding paragraphs.

For example, European Patent Application Publication No. 0093093 (Astra Meditec AB) discloses a process for the manufacture of a PVC urinary catheter having a covered hydrophilic outer surface exhibiting a low coefficient of friction when wetted. The process involves a hydrophilic coated surface on the PVC catheter by sequential application of a solution containing between 0.05-40% (weight / volume, that is, kg / 1) of an isocyanate compound and a solution of poly inylpyrrolidone (PVP) containing between 0.5-50% (weight / volume) of the outer surface of the catheter, for example by immersion, and then curing the hydrophilic coverage at an advantageously elevated temperature in the presence of a gas containing water such as ambient air.

The convenience of PVC for medical devices such as catheters, however, is now questioned in the environmental field and also because the toxicity of plasticizers is added to PVC. In addition, the coating of PVC catheters by, for example, the process of European Patent Application Publication No. 0093093 results in an appreciable decrease of the PVC catheter in the longitudinal direction, typically 6-7% of the original length, due to the operating temperatures used in the coating processes. The obvious disadvantage of such appreciable decrease is the wear of the material this in the sense that the long length PVC catheters eventually require this to be used at a decrease amount. Additionally, the quality control of the coverage processes becomes more complicated than those that would be ideal for these marked degrees of decrease.

It is, therefore, a necessity for the medical device that has a hydrophilic coated non-PVC extended handle surface to be inserted into body conduits that show no appreciable decrease in the application of a hydrophilic surface coating.

Description of the invention.

For this purpose, the present invention provides a method for manufacturing a medical device having an extended hydrophilic surface covering handle for inserting into body conduits comprising the steps of having the extended handle formed of a selected thermoplastic elaer material. of the group consisting of a polyether block amide and a styrene block copolymer and forming the hydrophilic coating on the handle extended by the sequential application to the extended handle surface of a solution comprising between 0.05-40% (weight / volume) of an isocyanate compound and a solution containing between 0.5 and 50% (weight / volume) of polyvinylpyrrolidone and curing at an elevated temperature.

The use of a polyether block amide or a styrene block copolymer results in an extended handle that has no substantial decrease compared to PVC in the application of a hydrophilic coating or by providing an extended handle with the normal properties required for the insertion of the fibers. same in the body canal. The present invention therefore makes it possible to provide a catheter which addresses the aforementioned disadvantages of PVC-based catheters first in order to reduce the losses in the starting materials and the possibility to use TV monitors for quality control.

While in the background section of European Patent Application Publication No. 0566755 (Cordis Corp.) the use of polyether block amide in the manufacture of a medical device in the form of a tube projected to be inserted in a body duct is known per se, European Patent Application Publication No. 0566755 shows that the undesirable blooming increases in the material of such tubes after they were ed for a time, can interfere with the adhesion of the cover of this , for example a cover to lubricate the tube. The solution to the burgeoning problem in accordance with European Patent Application Publication No. 0566755 is to knead the polyether amide block with a polyetherramide component which has substantially no ester linkages.

No problem with the adhesion of the hydrophilic coating to the polyether amide block manifests itself when the method of the present invention is followed in spite of the fact that the florescence is sometimes observed after some months of age. This can be attributed to the manner in which the hydrophilic cover is applied to the extended handle in the method according to the invention.

The polyether amide block used in the invention is believed to have a structure like the following HO - [. C-AP -C - O - PE - O -] "- H OR wherein PA is polyamide, PE is polyether and n is an integer greater than 1 which represents the numbers of the molecular copolymer blocks of repeating units within the molecular formula of the copolymer. Representative materials of the polyether amide block include the Pebax® polymers (Elf Atochem S.A.).

In one embodiment of the invention, the styrene copolymer block is a block of styrene-ethylene / butylene-reactive, for example Evoprene® G (Evode Plastics Ltd).

The application of the isocyanate solution to the surface of the extended handle has non-reactive isocyanate groups that form on the surface of the extended handle. The application of the polyvinylpyrrolidone solution to the extended handle surface results in a hydrophilic interpolymer cover of polyvinylpyrrolidone-polyurea formed on the surface of the extended handle. In order to cure these hydrophilic roofing joints, the isocyanate compounds are brought together to form a stable non-reactive channel of the hydrophilic polyvinylpyrrolidone bonds. Advantageously, the cure takes place in the presence of water containing gas, for example ambient air, to allow the isocyanate groups to react with the water to provide an amine that reacts rapidly with other isocyanate groups to form a cross-linkage of urea.

In one embodiment of the invention the method further comprises the steps of evaporating the solvent from the isocyanate solution prior to the application of the poly-inylpyrrolidone solution and evaporating the solvent from the poly-inylpyrrolidone solution prior to curing the hydrophilic shell. This is, for example, executed by dry air.

In one embodiment of the invention, the isocyanate compound comprises at least two non-reactive isocyanate groups per molecule. The isocyanate is selected from 2,4-toluene diisocyanate and di-isocyanate of, -di phenylmethane, or a pentamer of hexamethylene diisocyanate and toluene diisocyanate of the cyanurate type, or tristized hexamethylene diurethane diisocyanate or mixtures of the same solvent for the isocyanate compounds it is preferably one that does not react with isocyanate groups. The preferred solvent is methylene chloride, but it is also possible to use ethyl acetate, acetone, chloroform, methyl ethyl ketone and ethylene dichloride, for example.

The isocyanate solution may advantageously contain between 0.5 to 10% (weight per volume) of the isocyanate compound. Generally, the isocyanate solution only needs to make contact with the surface briefly, for example 5 to 60 seconds.

To increase the adhesion of the hydrophilic cover to the extended handle surface, the extended handle may be pre-swollen in a suitable solvent. Another way is to choose a solvent for the isocyanate solution that has the ability to swell or dissolve the surface of the extended handle to be covered.

To put in order the short reaction times needed and healing times, catalysts can be added to cure the isocyanate. These catalysts can be dissolved in either an isocyanate solution or a polyvinylpyrrolidone solution but it is preferable to dissolve it in the latter. Different types of amine are especially useful, for example diamines, but also for example triethylene diamine. Preferably, an aliphatic amine is used which is volatilizable at the drying and curing temperatures used for coverage, and which, furthermore, are non-toxic. Examples of these suitable amines are N, N'-diethylethylenediamine, hexamethylenediamine, ethylenediamine, adiaminobenzene, diester of 1,3-propanediol-para-aminobenzoic acid and diaminobicyclo-octane.

Where the catalyst is in the solution of polyvinylpyrrolidone, the proportion of catalyst in the solution is conveniently between 0.1 to 50% by weight of the amount of polyvinylpyrrolidone, preferably between 0.1 to 10% by weight. Some of the amines mentioned above, particularly the diamines, can also react with isocyanate and, therefore, contribute to the cross-linking of the isocyanate compounds that give the desired strength of adhesion between the hydrophilic shell and the surface of the polymer.

The polyvinylpyrrolidone preferably used as a medium of molecular weight of between 104 to 107 with the more preferred molecular weight medium of about 105. The polyvinylpyrrolidone having such a molecular weight is commercially available, for example under the trademark Kollidon® (BASF). Examples of suitable solvents for polyvinylpyrrolidone which can be used are methylene chloride (preferably), ethyl acetate, acetone, methyl ethyl ketone and ethylene dichloride. The proportion of polyvinylpyrrolidone in the solution is preferably between 0.5 to 10% (weight for volume) and more preferably between 2 to 8% (weight for volume). The polyvinylpyrrolidone in the solvent is applied by dipping, spraying or the like for a short period of time, for example, for 5 to 10 seconds.

The curing of the cover is preferably carried out at a temperature of 50 to 130 ° C, in, for example, an oven, for a duration of between 5 to 300 minutes.

In accordance with the invention, there is further provided a medical device having an extended covered handle, with a hydrophilic surface, for insertion into the conduits of the body manufactured by the method according to the invention.

According to the invention, there is further provided another medical device having an extended handle covered with hydrophilic surface for inserting into the body conduits, the extended handle made from a block of polyether amide or a block of styrene copolymer and provided with a covered outer surface formed of an interpenetrating channel of polyvinylpyrrolidone and polyurea.

According to the invention there is further provided a medical device having an extended handle for inserting into the body conduits, the extended handle made from a block of polyether amide or a block of styrene copolymer and provided with a hydrophilic outer shell surface of polyvinyl pyrrolidone having an increased osmolality.

In one embodiment of the invention, the hydrophilic coating contains an osmolality enhancing compound, to illustrate an inorganic salt selected from potassium and sodium chlorides, iodides, citrates and benzoates. The osmolality increase compound can be applied in the manner detailed in the above European Patent Application Publication No. 0217771.

In one embodiment of the invention, the medical device is a catheter, for example, those designated for urological, angi-oplás ti eos and valoplás ti eos or similar uses. In this case, the polyether amide block or the styrene copolymer block selected for the extended handle has a respective hardness in the range of 25 Sh D up to 70 Sh D and 40 Shore A up to 70 Shore D. Where the medical device is a urinary catheter, ideally a hardness in the range of 25 Sh D up to 45 Sh D for polyether amide blocks, and 40 Shore D for styrene copolymer block with preferred higher hardness for intravascular catheters.

In accordance with the invention there is also provided the use of a styrene copolymer block in the manufacture of a medical device having an extended handle for inserting into body conduits.

The invention is now illustrated, but not limited, by the following examples.

Example 1 A diisocyanate (called Desmodur IL) is dissolved in methylene chloride to a concentration of 2% (weight / volume). A urinary catheter formed exclusively or exclusively essentially of Pebax® (hereinafter a "Pebax® urinary catheter") with a hardness of 70 Shore D is immersed in a solution for 15 seconds and then dried at room temperature for 60 seconds. The catheter is then soaked for 1 second in a solution containing 6% (weight / volume) of polyvinylpyrrolidone (K90, average molecular weight -360 000) dissolved in methylene chloride. The catheter is then allowed to dry at room temperature for 60 seconds and finally cured for 50 minutes at 100 ° C. The catheter is finally allowed to cool to room temperature and then rinsed in water. The catheter has a slippery, sticky surface where there is moisture.

The experiment was repeated with variations in the time of immersion in the isocyanate bath in a range from 5 seconds to 1 minute, but no advantages were obtained to increase the immersion time.

Example 2 A diisocyanate (called Desmodur IL) is dissolved in ethyl acetate to a concentration of 2% (weight / volume). A Pebax® urinary catheter with a hardness of 35 Shore D is soaked in this solution for 15 seconds and then dried at room temperature for 60 seconds.

The catheter is then soaked for 1 second in a solution containing 6% (weight / volume) of polyvinylpyrrolidone (K90, molecular weight -360 000) dissolved in ethyl lactate (50%) and ethyl acetate (50%). The catheter was then allowed to dry at room temperature for 60 seconds and finally cured for 50 minutes at 80 ° C. The catheter was finally allowed to cool to room temperature and then rinsed with water. The catheter has a slippery, sticky surface where there is moisture.

Example 3 A diisocyanate called Desmodur IL) was dissolved in methylene chloride (75 μl and trichlorethylene (25%) to a concentration of 2% (weight / volume). A Pebax® urinary catheter with a hardness of 63 Shore D was soaked in this solution for 15 seconds and then dried at room temperature for 60 seconds.The catheter was then soaked for 1 second in a solution containing 6% (weight / volume) of polyvinylpyrrolidone (K90; average molecular weight ~ 360,000) dissolved in sodium chloride. methylene (75%) and trichlorethylene (25%) The catheter was allowed to dry at room temperature for 60 seconds and finally cured for 50 minutes at 100 ° C. The catheter was finally allowed to cool to room temperature and rinsed then with water, the catheter has a slippery and sticky surface where there is moisture.

Example 4 A diisocyanate (called Desmodur IL) was dissolved in ethyl acetate to a concentration of 2% (weight / volume). A urinary catheter manufactured from Evoprene® G with a hardness of 65 Shore A was soaked in this solution for 15 seconds and then dried at room temperature for 60 seconds. The catheter was then soaked for 1 second in a solution containing 6% (weight / volume) of polyvinylpyrrolidone (K90; molecular weight = 360,000) dissolved in methylene chloride. The catheter was then allowed to dry at room temperature for 60 seconds and finally cured for 50 minutes at 100 ° C. The catheter was finally allowed to cool to room temperature and then rinsed with water. The catheter has a slippery, sticky surface where there is moisture.

The urinary catheters prepared according to the examples show low friction, good writh resistance, good dimensional stability and possibility of being sterilized. Furthermore, the longitudinal decrease of the catheters as a result of the coverage processes was less than 1% of the original length.

Although the examples refer to the manufacture of urinary catheters it will be understood that the invention is not restricted for this single application but is equally applicable to other forms of catheters and still more other constructions that fall within the general classes of medical devices that have an elongated handle adapted to enter the body passages completely, to illustrate transverse devices for treating erectile dysfunction and drainage of wounds to insert into the ducts of the human body in the form of open cavities.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Having described the invention as above, the content of the following is claimed as property.

Claims (24)

Claims

1. A method for the manufacture of a medical device, having an extended handle of hydrophilic coated surface for inserting into the body conduits, characterized in that it comprises the steps of having an extended handle formed of a thermoplastic elastomer material, selected from the group consisting of a polyether block amide and a styrene block copolymer and forming the hydrophilic coating on the extended handle by sequential application to the extended handle surface, of a solution comprising between 0.05 to 40% (weight / volume) of an isocyanate compound and a solution containing between 0.5 and 50% (weight to volume) of polyvinylpyrrolidone and curing at elevated temperature.

2. The method according to claim 1, characterized in that the isocyanate compound comprises at least two non-reactive isocyanate groups per molecule.

3. The method according to claim 1 or 2, characterized in that the solvent of the isocyanate solution is an organic solvent that does not react with isocyanate.

. The method according to claim 1, 2 or 3, characterized in that the additional method comprises the steps of evaporating the solvent from the isocyanate solution prior to the application of the polyvinylpyrrolidone solution and evaporating the solvent from the polyvinylpyrrolidone solution prior to the healing

5. The method according to any of the preceding claims, characterized in that the curing is carried out in the presence of water containing gas.

6. The method according to any of the preceding claims, characterized in that the curing is carried out at a temperature between about 50 and 130 ° C.

7. The method according to any of the preceding claims, characterized in that the styrene block copolymer is a block copolymer is styrene-ethylene / butylene-tyne.

8. The method according to any of claims 1 to 6, characterized in that the polyether block amide selected for the extended handle has a hardness in the range of 25 Sh D to 70 Sh D.

9. The method according to claim 7, characterized in that the block copolymer is t irene-e t ileno / bu t ileno-styrene, selected for the extended handle, has a hardness in the range of 40 Sh A to 70 Sh D.

10. The method according to any of the preceding claims, characterized in that the isocyanate is selected from 2,4-toluene diisocyanate and 4,4'-diphenylmethane diisocyanate, or a pentamer of hexamethylene diisocyanate and toluene diisocyanate of the cyanurate type, or diisocyanate hexamethylene trimerized biuret or mixtures thereof.

11. The method according to any of the preceding claims, characterized in that the method comprises the steps of applying to the hydrophilic coating a solution containing a compound that increases the osmolality and evaporates the solution containing the compound that increases the osmolality.

12. The method according to claim 11, characterized in that the compound that increases osmolality is an inorganic salt selected from sodium and potassium chlorides, iodides, citrates and benzoates.

13. A medical device characterized in that it has an extended handle of hydrophilic surface for inserting into the conduits of the body manufactured by the method according to any of claims 1 to 12.

14. The medical device having an extended handle for inserting into body conduits, characterized in that the extended handle is made from a polyether block amide or a styrene block copolymer and is provided with a hydrophilic outer surface formed for a channel interpenetrating polyvinylpyrrolidone and polyurea.

15. The medical device having an extended handle for inserting into the body conduits, characterized in that the extended handle is made from a polyether block amide or a styrene block copolymer and provided with an outer surface coating of hydrophilic polyvinylpyrrolidone which It has an increase in osmolality.

16. The medical device according to claim 14 or 15, characterized in that the styrene block copolymer is a block copolymer is tyrene-ethylene / butylene-t-styrene.

17. The medical device according to claim 14 or 15, characterized in that the extended handle is formed from a polyether block amide having a hardness in the range of 25 Sh D up to 70 Sh D.

18. The medical device according to claim 16, characterized in that the extended handle is formed from a block copolymer is tireno-et ileno / but ileno-is tir eno that has a hardness in the range of 40 Sh A to 70 Sh D.

19. The medical device according to any of claims 14 to 18, characterized in that the hydrophilic coating contains a compound that increases osmolality.

20. The medical device according to claim 19, characterized in that the compound that increases the osmolality is an inorganic salt selected from potassium and sodium chlorides, iodides, citrates and benzoates.

21. The medical device according to any one of claims 13 to 20, characterized in that the device is a catheter.

22. The medical device according to claim 21, characterized in that the device is a urinary catheter.

23. The use of a styrene block copolymer in the manufacture of a medical device having an extended handle for inserting into body conduits.

24. The use according to claim 23, wherein the styrene block copolymer is a styrene-ethylene / butylene-styrene block copolymer.