JPS5836974B2 - Double structure infusion tube and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a medical infusion tube with a double structure and a method for manufacturing the same, in particular, a medical infusion tube with a double structure obtained by coaxial coextrusion of different resins and the manufacturing method thereof. Regarding the method.

Conventionally, blood collection, blood transfusion, infusion sets, artificial blood circuits, etc.
Soft polyvinyl chloride (hereinafter abbreviated as "PVC") is used as a material for infusion tubes used in the medical field to collect, transport, or inject blood or medicinal fluids into the human body. Ta.

This is because PVC has all the properties required as a material for infusion tubes, such as transparency, flexibility, resiliency, chemical resistance, heat resistance, and cold resistance, all at a high level, and is also inexpensive and sanitary. This is because it is also suitable for disposable ("disposable") products.

However, when PVC is used for such purposes, it is recognized that relatively low-molecular substances such as plasticizers and stabilizers are eluted into blood or drug solutions during use, and the toxicity of these substances may be a problem. Due to this, the application of PVC to infusion pipes is becoming a problem.

Furthermore, it has recently become clear that PVC has poor blood compatibility.

In other words, it was found that considerable hemolysis occurs when red blood cells come into contact with the PVC surface, and its anticoagulant properties are also considerably lower than that of silicone or hydroxyalkyl (meth)acrylate polymers, making PVC never suitable for medical use. It can be said that it is not a desirable material.

In view of the current situation, the present inventor intended to develop an infusion tube that can be used safely without the above concerns.

In that case, considering the excellent suitability of PVC to the various performance requirements mentioned above, it is not so easy to think of a material that can completely replace PVC. We determined that it would be more practical to solve these drawbacks, and as a result of intensive study of means to achieve this goal, we arrived at the present invention.

According to the present invention, PVC is used on the outside, and thermoplastic polymer material, which is biocompatible and does not substantially elute harmful substances when it comes in contact with blood, body fluids, or medical fluids, is used on the inside as the inner wall material of the infusion tube. are simultaneously melted and extruded on a coaxial circumference, and while both are in a molten state, they are integrally bonded, and the whole is cooled and solidified from 1 to 30 days later, thereby combining the outer tube made of PVC and the above-mentioned heat. A double structure infusion tube is obtained in which the inner tube made of a plastic polymer material is integrally joined.

As the vinyl chloride used in the present invention, a soft vinyl chloride composition, which has been conventionally used for manufacturing infusion tubes, is mainly used.

However, soft vinyl chloride compositions based on other formulations may be used, or they may be used for transporting infusion tubes or soft tubes that do not come into direct contact with the human body, or for connecting portions between soft tubes and channels of equipment, etc. In the case of an infusion tube, a rigid vinyl chloride composition may be used.

According to the present invention, a thermoplastic polymer material that is used as an inner wall material for an infusion tube is a thermoplastic polymer material that does not substantially elute harmful substances when it comes into contact with blood, body fluids, or medicinal fluids, has low toxicity, and has good biocompatibility. Ethylene-vinyl acetate copolymer, thermoplastic polyurethane or polycarbonate is used.

To melt-extrude these two types of thermoplastic materials simultaneously in a coaxial circumferential shape, each material is plasticized separately using two extruders, and then they are introduced into one die and extruded.

The die may be such that the flow paths of the two materials remain coaxial circumferentially therein but merge into a single circumferential aperture, or may have one or two separate coaxial circumferential apertures. It may also have a part.

In the former case, the integral joining of the inner and outer tubes is carried out in a die, while in the latter case, the inner and outer tubes are joined together after extrusion and before cooling, for example by applying air pressure inside the inner tube. The inner tube and outer tube are integrally connected by bringing them into close contact with each other.

Any known means may be used to cool and solidify the tubes integrally connected in this way, but gradual cooling is more desirable than rapid cooling.

The double-structured infusion tube thus obtained does not allow the liquid to be infused to come into direct contact with the PVC, allowing it to be used without worrying about the elution of harmful substances from the PVC, as well as having anti-hemolytic and anti-coagulant properties. Improvement in sex is seen.

Moreover, by appropriately determining the thickness of the inner tube, the mechanical performance of the entire tube can be made to be almost the same as that of PVC pipes, so when actually used, it is possible to use conventional PVC infusion pipes. It can be easily applied to conventional PVC infusion tubes.

Examples are shown below.

Example 1 A polyvinyl chloride soft composition (containing a phthalate ester plasticizer by weight of 55% of the resin weight) conventionally used to manufacture infusion tubes was used as an outer tube material and thermoplastic polyurethane (trademark Meiko Lastran). is used as the material for the inner tube, and the outer tube thickness is 0. A double-walled tube was extruded through a die with a single circumferential opening so that the inner tube thickness was 0.1 mm and the inner tube diameter was 5 mm.

At this time, the temperature at the extruder breaker plate was set at 160°C for vinyl chloride and 180°C for polyurethane.

The thus obtained double-structure tube was bent 1,000 times at right angles by gripping it with a clamp having a width of about 2 cm at the point where it reached 8 cm, but no separation occurred between the inner tube and the outer tube.

1. The double-walled tube was filled with water and physiological saline and left at room temperature for two days and nights, but the adhesion between the inner tube and outer tube was strong and no peeling was observed.

Next, a 10 m double-structured tube that had been left at room temperature for 10 days after extrusion was filled with 200 ml of distilled water, both ends of which were closed, and the tube was immersed in a constant temperature water bath at 70° C. for 2 hours to perform extraction.

The amount of phthalate DOP in the obtained extract was analyzed by gas chromatography and was found to be 0.070 TIg.

On the other hand, when a similar experiment was conducted using a conventional PVC pipe as a control, the amount of DOP eluted was 0.25 ml, which clearly shows that the double-structured pipe suppresses the elution of DOP.

Example 2 In the same manner as in Example 1, vinyl chloride and ethylene-hinyl acetate copolymer (trade name: Evaflex, vinyl acetate content 25% by weight) were co-extruded to obtain a double-structured tube having an Evaflex inner tube. Ta.

The adhesion between the outer tube and the inner tube of this tube was good both in dry and wet conditions.

Next, the double structure tube and the PVC tube with the same inner diameter were each filled with 10P of distilled water, both ends were closed, and the tubes were boiled in a water bath for 1 hour to perform extraction.

When the amount of potassium permanganate reducing substances was quantified in the obtained extract, the consumption amount of 0.0 IN potassium permanganate (per 12 extracts) for the double-walled tube and the control PVC tube was 1/ZO. ．． 1 3 ml, 0
．． The volume was 30 ml.

By introducing the Evaflex inner tube, the elution amount of potassium permanganate reducing substances was clearly reduced.

Example 3 A hemolytic test on the inner surface of the tube was conducted using the following method for the double-walled tube obtained in Example 2.

Blood cells are extracted from dog ACD blood by centrifugation,
Phosphate isotonic buffer (NaCl 7.6 5?, Na2
HPO4-1 2 H20 2.9 3? , NaH2
PO4・2H200.21f, glucose 5? (dissolved in water to make 1 t), diluted to 10 volumes, put 3 ml into the test tube, let it stand for 87 hours in a thermostatic water bath at 37°C, shake it gently, centrifuged it, and poured it up. The clear sample was taken out, diluted 100 times, and the relative amount of hemoglobin dissolved in water due to the destruction of red blood cells was measured using an ultraviolet absorption spectrum (414
The absorbance was measured using mμ absorbance A414).

The results obtained for the double-walled tube and several comparative samples (inner diameter between 4 and 5) are shown in the table below.

It can be seen that the double-walled tube of the present invention whose inner tube is made of Evaflex has considerably less hemolysis of blood that splatters on the inner wall of the tube than a tube made only of PVC, and is superior to conventional products as a transfusion tube. .

Next, the anticoagulant properties of the Chloride B-Evaflex double tube were compared and evaluated with commercially available medical PVC tubes and silicone tubes using the Lee-White test method as reference.

The anticoagulant properties of the Chloride B-Evaflex double-coated tube were superior to that of the control PVC tube, and were comparable to that of the medical silicone tube used for comparison.

Example 4 Polyvinyl chloride soft composite material (containing phthalate ester plasticizer by 40% of resin weight) was used as the material for the outer tube, thermoplastic polycarbonate (trade name: Ubilon) was used as the material for the inner tube, and the outer tube thickness was 0. 8mm, inner tube thickness 0. 1 wn
The double-walled tube was extruded through a die with a single circumferential opening so that the inner diameter of the tube was 5 mm.

The resin temperature at this time is PVC 200℃, polycarbonate 2
The temperature was set at 40°C.

The adhesion between the outer tube and the inner tube of the double-walled tube thus obtained was good both in dry and wet conditions.

Next, the double-walled tube and a single PVC tube with the same inner diameter as a control were each filled with distilled water of IOP, both ends were closed, and the tubes were boiled in a water bath for one hour to perform extraction.

When the potassium permanganate reducing substance was quantified in the obtained extract, the amount of potassium permanganate consumed at 0.0 IN (per 1 i of extract) for the double-walled tube and the control PVC tube was 0.000. osmg, 0.28 ml.

The introduction of the polycarbonate inner tube clearly reduced the amount of potassium permanganate reducing substances eluted.

Claims (1)

[Claims] 1. An outer tube made of a composition mainly composed of polyvinyl chloride;
A double tube that is made of an inner tube made of ethylene-vinyl acetate copolymer, thermoplastic polyurethane, or polycarbonate and is less harmful when it comes in contact with blood, body fluids, or medical fluids and has excellent biocompatibility. Structure infusion tube. 2. Melt and extrude the composition mainly composed of polyvinyl chloride on the outside and the ethylene-vinyl acetate copolymer, thermoplastic polyurethane, or polycarbonate on the inside at the same time in a coaxial circumferential shape, so that both are melt-extruded. A double-structured infusion solution that is less harmful when it comes into contact with blood, body fluids, or medicinal fluids and has excellent biocompatibility, and is characterized by integrally binding the two components while the fluid is still in the state, and then cooling and solidifying the entire body. Method of manufacturing tubes.