MXPA97004547A

MXPA97004547A - Cateter and process for your manufacturer

Info

Publication number: MXPA97004547A
Application number: MXPA/A/1997/004547A
Authority: MX
Inventors: Utas Jan
Original assignee: Astra Ab
Priority date: 1994-12-22
Filing date: 1997-06-18
Publication date: 1998-07-03

Abstract

The invention relates to a process for manufacturing a catheter for insertion into a body cavity, for example, of the type used for insertion into the urethra. The catheter has a tip portion provided with one or more drainage or discharge openings adjacent to the free end which is to be inserted into the body cavity, and the exterior of the catheter is provided with a coating. The process comprises the steps of injection molding a separate tip portion of the catheter, the tip portion includes an inner lumen and the drain / discharge openings, and the inner and outer diameters of the tip correspond to those of a standard tube. , forming one end of the standard tube and one end of the tip portion to conform to each other for a subsequent joining operation, and joining the tip to the standard tube in a joining operation, in which the coating is applied to the standard tube before that the joining operation is carried out. The invention also relates to a catheter manufactured by the process

Description

CATHETER AND PROCRSO FOR ITS MANUFACTURING TECHNICAL FIELD DB LA INVBMCT-QM The present invention relates to a process for manufacturing a catheter, for example of the type used for insertion into the urethra, the catheter is preferably coated with a layer of hydrophilic material, the catheter is additionally provided with a drainage opening or discharge adjacent to the free end which is to be inserted into the urethra.

Hydrophilically coated catheters are known, for example, from US-A-4585666 and US-A-4666437 (Lambert / Astra Meditec AB) or US-A-4906237 (Johansson et al. / Astra Meditec AB). US-A-4773901 (Norton / C, R. Bard, Inc.) discloses a catheter with a selectively rigidified tip portion. The tip is coated with a hydrophilic polymer which absorbs or adsorbs water in use so that it returns to the soft tip. A commonly used technique when manufacturing catheters of the above type is to use a tube REF: 24882 extruded flexible made of polymeric material such as PVC or polyethylene, or a similar material and which has appropriate dimensions as initial material. The end of the tube is welded or closed by welding, or otherwise closed at one end. If desired, the exterior of the catheter is then provided with a hydrophilic layer. The drain / drain hole is subsequently drilled in the tube. A first way of performing the drilling operation can be by means of an oblique movement in relation to the tube, in which a partially circular part of the side walls of the tube is cut by means of the perforation. A disadvantage with this drilling operation is the difficulty of obtaining an exact hole size, since a small error in the alignment of the perforation or in the dimension of the tube will result in a large difference in the size of the drilled hole. This difficulty in obtaining the exact size of a hole can be corrected by using a second way of carrying out the drilling operation. In this second operation, the perforation is centered on the tube and lowered onto the tube, compressing the side walls of the tube together and drilling through the uppermost side wall, and stopping the hole drilling operation before there is a risk of penetration of the lower lateral wall. The hole that results from this drilling operation is always the same size. The difficulties associated with this operation is to decide the exact moment at which to stop the drilling operation so as to ensure that one side wall has been completely penetrated but the other side wall, with certainty, has not been penetrated. It may be easier to adjust the perforation exactly when the holes are drilled in standard uncoated tubes having well-defined wall thicknesses, but it may be different when the tubes have been coated with a layer, for example a hydrophilic layer, since the layer affects the dimensions of the pipeline, at least to some extent. Another problem in the manufacture of coated catheters arises when the catheter made of a standard tube is formed with a curved tip (eg, the so-called Tiemann catheter), since the heat treatment related to the coating procedure or subsequent sterilization it may result in the tip straightening again due to "memory" (tendency to regain its primitive shape) or to the remaining tensions, not corrected in the polymer in the tube. The "memory" of the material can be defined as the tendency of the material to resume its original form due to the inherent orientation of the material.

DESCRIPTION OF THE INVENTION According to the invention, the above difficulties are solved insofar as a tip portion of the catheter, which includes the inner lumen and a drain / discharge orifice, is injection molded with inner and outer diameters corresponding to those of a standard tube, and later it is attached to a standard tube. Therefore, according to the present invention, there is provided a process for manufacturing a catheter for insertion into a body cavity, for example of the type used for insertion into the urethra, the catheter has a tip portion provided with one or more openings of drainage or discharge adjacent to the free end which is to be inserted into the body cavity, the exterior of the catheter is provided with a coating, characterized in that the process comprises the steps of: - injection molding a separate tip portion of the catheter , the tip portion includes an inner lumen and drainage / discharge openings, the inner and outer diameters of the tip correspond to those of a standard tube, - form one end of the standard tube and one end of the tip portion to conform between if for a subsequent joining operation, and - joining the tip to the standard tube in the joining operation, in which the coating is applied to The standard tube before the joining operation is performed. The difficulties encountered with drilling coated tubes is eliminated in this way. The process additionally allows the liner to extend over the entire length of the catheter, including the edges of the drain / discharge openings. This can be obtained by coating the tip after the joining operation is carried out. In this way, it is not necessary to immerse the entire assembled catheter in the coating medium. The lining can usually be carried out by mounting the catheter on stems or stainless steel pins. If the entire assembled catheter is to be immersed in the coating medium, the rods will be contaminated with the solution, as it enters through the opening in the tip. The use of the present invention means that, after the joining operation is performed, the catheter only needs to be submerged to the junction region. In this way, the internal lining of the catheter is minimized. In fact, it is further preferred to provide an injection molded tip with a coating before the bonding operation is carried out. In this way, substantial coating steps are not necessary after the joining operation is carried out. On the other hand, if after the joining operation is carried out a second coating operation is performed, it is ensured that the area of the catheter in the joint region is coated. It can be difficult to adhere the second coating, although this can be carried out by scraping part of the existing coating and removing it, for example 2 mm, before the second coating operation is carried out. Before the joining operation is performed, the coating can be applied to the standard tube by the additional steps of: fusing or otherwise connecting the end of the standard tube, coating the outside of the catheter with a layer, and - cutting the fused end or otherwise disconnect such extreme. In this way, the possible lining of the stainless steel rods and the interior of the catheter during this manufacturing stage are completely eliminated.

Any method can be used to join the tip to the standard tube, for example by pressure adjust or even by screwing. However, it is preferred that the tip be welded, adhered or adhered by solvents to the standard tube. A glue compatible with the solvent used for the coating may be used, for example, an adhesive which dissolves the solvent, so as to aid adhesion. The glue can extend partially into the lu but it should not be spilled too far, as this can reduce the diameter of the lu The use of an oblique cut can cause problems with the orientation of the standard tube in relation to the tip. Therefore, a straight cut perpendicular to the axis of the standard tube is preferably used. Any type of coating can be used, but the invention is particularly suitable if the coating is a hydrophilic coating. The invention allows a large amount of versatility in the type of tips that can be used.

Therefore, the tip can be molded to have a curved shape, as in the Tienmann catheter. The invention provides a more stable form thereof. Similarly, the tip does not need to be of the same material as the standard tube. It can be molded from a material which is softer than the material in the standard tube, or which is stiffer than the material in the standard tube. A rigid tip can be used if, for example, prostate problems are manifest. 5 The tip and the standard tube can be manufactured so easily from the same material. This will allow an easier bonding. Preferably, the catheter is made of a thermoplastic polymer such as PVC or polyethylene, or a : .Ó similar material. Such materials are ideal if the catheter is an intermittent urinary drainage catheter, as opposed to a balloon catheter for long-term use. There is no need to shrink the tip to a standard tube, as would be the case with balloon catheters. In a further aspect of the invention, a catheter manufactured by such a process is provided.

DESCRIPTION OF THE INVENTION A preferred embodi of the invention will now be described, by way of example, in the preferred embodi, the catheter is clad. with a hydrophilic layer, for example, according to the North American patents 4585666 and 4666437 (Lambert / Astra Meditec AB) or 4906237 (Johansson et al. / Astra Meditec AB). The catheter is manufactured by joining two parts, specifically a part formed by a standard tube, commercially available, for example made of PVC, and a part formed by an injection molded tip. Before the joining operation, the two parts of the catheter are coated with. a hydrophilic layer. The two parts of the catheter are coated by immersion in a coating solution. In order to prevent the coating material or the coating solution from entering the interior of the tube, the end of the standard tube can be fused or closed in some other way. Of course, the tube can also be coated by immersion along its entire length of the tube in the coating solution and at the same time it is ensured that the open ends of the tube will not be submerged in the solution. The end of the tube is then cut in order to form an end surface which is suitable for the joining operation in which it is to be used. The hollow tip portions for the catheter are manufactured separately by means of injection molding and the shape and properties of the tip in this manner can be adapted to the proposed use of the catheter. Then, the tip portion is immersed in the coating solution. In one embodi, the tip portion is held in a mandrel for filling or sealing the inner luof the tip portion, the tip portion after immersion is removed from the mandrel, but the coating solution in some cases can be allowed to reach the inner lumen of the tip. The most concealed (in use) or proximal end of the end portion is then cut to a shape complementary to the shape of the cutting end of the coated tube, and the two parts are joined. The two parts can be adhered by means of an appropriate glue or they can be joined by solvent, that is, the ends of the two catheter parts dissolve slightly in a suitable solvent and then pressed together. The two parts can also be welded together, for example by ultrasound. The invention described in the above has several important advantages. The opening in the catheter can be made rounded with smooth or regular edges and constantly with the same size. The edges of the openings are also coated. A curved "Tiemann" tip, injection molded, will tilt further to maintain the desired shape after heat treatment which may be involved in the coating and / or sterilized treatment as compared to a catheter which has been formed (or in addition, deformed) to a curved structure. If desired, the tip can be molded from a material which may be harder or softer than the material in the tube. The shape of the tip may vary to some extent so that a large number of different catheters are obtained for various uses. For example, a variation may be a "terminal eye" ie a rounded opening at the end of the catheter. Consequently, it will be easy to manufacture a wide range of catheters well suited for different uses and well suited for different types, shapes and courses of the body cavities into which the catheters are to be inserted as well as the manner in which they are to be inserted. catheters The classification of the catheters may be odularized since the same type of tip will be used for different catheter lengths. Finally, the length of the catheter can be decided after the lining procedure, since the problem of shrinkage will be of lesser importance compared to commercially available catheters to date. Unrelieved stresses in the polymer material in the part of the catheter tube that remain as a result of the manufacturing process can lead to shrinkage in subsequent calorific treatments such as coating or sterilization procedures.

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, property is claimed as contained in the following:

Claims

8VT-NDICACIQMES

1. A process for manufacturing a catheter coated on its outer surface, for insertion into a body cavity, the catheter has a catheter body which comprises a tip portion having a free leading end which has the free front end of the catheter body , and a rear end separated from the free front end, a tube portion which extends rearwardly from the rear end of the tip portion, a lumen having a forward portion at the tip portion, which extends forwardly. from the rear end of the tip portion, and a rear portion in the tube portion, which communicates with the front portion, and one or more drain or discharge openings in the tip portion, which communicate with the portion front of the lumen, the process is characterized in that it comprises: (a) a first stage comprising the steps of: (i) selecting a standard or conventional tube that has a front end and a rear end spaced apart to form the tube portion of the catheter with at least one section of the standard tube which is of predetermined inner and outer diameters, and (ii) injection molding the tip portion with the end rear thereof having inner and outer diameters substantially corresponding to the predetermined inner and outer diameters of the standard tube; (b) a second stage, comprising the steps of: (i) closing the front end of the standard tube, and (ii) then immersing the standard tube in coating material or coating solution in a forward direction to coat the surface outside of the standard tube; (c) a third step, comprising the steps of; (i) providing the standard tube coated with a free open end, which is presented by the section having predetermined inner and outer diameters, (ii) forming or adapting the rear end of the tip portion and the free open end of the tube coated standard, and (iii) attaching the back end of the tip portion to the free open end of the standard coated tube to form a catheter body; and (d) a fourth step, comprising the step of: (i) immersing the catheter body in coating material or coating solution to join the line or tubing between the tip portion and the tube portion to a substantially level equal to the connecting pipe between the tip portion and the tube portion for coating the outer surface of the tip portion.

2. A process for manufacturing a catheter coated on its outer surface, for insertion into a body cavity, the catheter has a catheter body which comprises a tip portion having a free leading end which has the free front end of the catheter body , and a rear end separated from the free front end, a tube portion which extends rearwardly from the rear end of the tip portion, a lumen having a forward portion at the tip portion, which extends forwardly. from the rear end of the tip portion, and a rear portion in the tube portion, which communicates with the front portion, and one or more drain or discharge openings in the tip portion, which communicate with the portion front of the lumen, the process is characterized in that it comprises: (a) a first stage comprising the steps of: (i) selecting a standard or conventional tube that has a front end and a rear end spaced apart to form the tube portion of the catheter with at least a section of the standard tube having predetermined inner and outer diameters, and (ii) injection molding the tip portion with the rear end thereof having inner and outer diameters which correspond substantially to the predetermined inner and outer diameters of a standard tube; (b) a second stage, comprising the steps of: (i) closing the front end of the standard tube, and (ii) then immersing the standard tube in coating material or coating solution in a forward direction to coat the surface outside of the standard tube; (c) a third step, comprising the step of: (i) immersing the tip portion in coating material or coating solution to coat the outer surface of the tip portion; and (d) a fourth step, comprising the steps of: (i) providing the standard tube coated with a free open end, which is presented by the section having predetermined inner and outer diameters, (ii) forming or adapting the back end of the coated tip portion and the free open end of the standard coated tube to each other, and (iii) attaching the back end of the coated tip portion to the free open end of the standard coated tube to form a coated catheter are surface Exterior.

3. The process according to claim 1 or 2, characterized in that the section of the standard tube having predetermined inner and outer diameters - is a front section which presents the front end of the standard tube and the free open end of the standard tube is provided at do not close the front end of the standard coated tube or by cutting off the closed front end.

4. The process according to claim 3, characterized in that the standard tube is immersed in material / coating solution forward, up to a level behind the front section of the standard tube and forward of the rear end of the standard tube.

5. The process according to any of claims 1 to 4, characterized in that, after the joining operation is carried out, a second coating operation is carried out, whereby it is ensured that the area of the catheter in the region of the union is coated.

6. The process according to any of claims 1 to 5, characterized in that the tip portion is soldered, glued or stick with solvent to the standard tube.

7. The process according to any of the preceding claims, characterized in that the coating is a hydrophilic coating.

8. The process according to any of the preceding claims, characterized in that the tip portion molds to a curved shape.

9. The process according to any of the preceding claims, characterized in that the tip portion is molded from a material which is softer than the material in the standard tube.

10. The process according to any of claims 1 to 8, characterized in that the tip portion is molded from a material which is stiffer than the material in the standard tube.

11. The process according to any of the preceding claims, characterized in that the catheter is made of a thermoplastic polymer.

12. The process according to claim 11, characterized in that the thermoplastic polymer comprises PVC or polyethylene, or a similar material.

13. A catheter characterized in that it is manufactured by the process according to any of the preceding claims.

14. The catheter manufactured according to claim 13, characterized in that the catheter is an intermittent urinary drainage catheter. RESOMBT OF THE PCB Fa The invention relates to a process for manufacturing a catheter for insertion into a body cavity, for example, of the type used for insertion into the urethra. The catheter has a tip portion provided with one or more drainage or discharge openings adjacent to the free end which is to be inserted into the body cavity, and the exterior of the catheter is provided with a coating. The process comprises the steps of injection molding a separate tip portion of the catheter, the tip portion includes an inner lumen and the drain / discharge openings, and the inner and outer diameters of the tip correspond to those of a standard tube. , forming one end of the standard tube and one end of the tip portion to conform to each other for a subsequent joining operation, and joining the tip to the standard tube in a joining operation, in which the coating is applied to the standard tube before that the joining operation is carried out. The invention also relates to a catheter manufactured by the process.