LUBRICANT REGULATING AGENT

Abstract

The present invention makes the insertion perception during actual surgery to be equivalent to the insertion perception of a catheter into a blood vessel model when water is used as the circulating fluid. A lubricant regulating fluid primarily composed of water is mixed with an aqueous metal salt and a surfactant as a lubricant regulating agent of the lubricant regulating fluid. A cationic surfactant, an anionic surfactant, a nonionic surfactant, or a dipolar ionic surfactant may be used as the surfactant. Also, the metal salt may be an alkaline metal salt, an alkaline earth metal salt, an aluminum salt, a ferric salt, or the like. In an example, the lubricant regulating fluid obtained by mixing an aqueous metal salt with water is prepared, and the lubrication and non-adherent properties of a catheter into a simulated blood vessel model are improved.

Claims

1. A method for regulating the lubricity of a surface in a blood vessel model to achieve a realistic feeling similar to blood when a catheter is inserted into said blood vessel model, comprising providing said blood vessel model for the catheter simulator with a lubricity regulating liquid that includes water, a surfactant, and a water-soluble ionic compound being one or more selected from the group consisting of an alkali metal salt, an alkali earth metal salt, an aluminum salt, and an iron salt.

2. The method of claim 1, wherein said lubricity regulating liquid is in contact with said surface in the blood vessel model and thereby regulates lubricity by increasing an index of lubricity for the inserted catheter in comparison to either water alone or water with a surfactant.

3. The method of claim 1, wherein said blood vessel model is a catheter simulator made of silicone rubber.

4. The method of claim 1, wherein the surfactant is one or more selected from the group consisting of a cationic surfactant, an anionic surfactant, a nonionic surfactant and a zwitterionic surfactant.

5. The method according to claim 1, wherein the surfactant comprises at least a cationic surfactant.

6. The method according to claim 4, wherein the surfactant comprises at least a cationic surfactant.

7. The method of claim 1, wherein a concentration of the water-soluble ionic compound ranges from 1 mmol/L to 100 mmol/L.

8. The method of claim 1, wherein a concentration of the surfactant ranges from 0.005 mmol/L to 100 mmol/L.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] FIG. 1 is a front view of a pseudo blood vessel model used in a lubricity evaluation test.

[0033] FIG. 2 is a graph showing the relation between the rotation angle and the concentration of a metal salt in a test for evaluating the lubricity of lubricity regulating liquids of Examples 1 to 8.

[0034] FIG. 3 is a graph showing the relation between the rotation angle and the concentration of a metal salt in a test for evaluating the lubricity of lubricity regulating liquids of Examples 9 and 16.

[0035] FIG. 4 is a graph showing the relation between the rotation angle and the concentration of a metal salt in a test for evaluating the lubricity of lubricity regulating liquids of Examples 10 and 11 and Comparative Examples 10 and 11.

[0036] FIG. 5 is a graph showing the relation between the rotation angle and the concentration of a metal salt in a test for evaluating the lubricity of lubricity regulating liquids of Example 12 and Comparative Example 12.

[0037] FIG. 6 is a graph showing the relation between the rotation angle and the concentration of a metal salt in a test for evaluating the lubricity of lubricity regulating liquids of Example 13 and Comparative Example 13.

[0038] FIG. 7 is a graph showing the relation between the rotation angle and the concentration of added bittern in a test for evaluating the lubricity of a lubricity regulating liquid of Example 14.

[0039] FIG. 8 is a graph showing the relation between the rotation angle and the concentration of an added surfactant in a test for evaluating the lubricity of a lubricity regulating liquid of Comparative Example 14-1.

[0040] FIG. 9 is a graph showing the relation between the rotation angle and the concentration of an added bittern in a test for evaluating the lubricity of a lubricity regulating liquid of Comparative Example 14-2.

[0041] FIG. 10 is a graph showing the relation between the rotation angle and the amount of added MgCl.sub.2 in a lubricity evaluation test using silicone rubber (1) and silicone rubber (2).

MODES FOR CARRYING OUT THE INVENTION

Examples

[0042] Hereinafter, the present invention will be explained in detail by way of Examples, but is not limited to the following Examples. Various modified embodiments are also encompassed within the scope of the present invention, so long as they would be obvious to those skilled in the art without departing from the scope of claims.

Examples 1 to 8

[0043] In Examples 1 to 8, a 16-wt % aqueous solution containing, as surfactants, sodium alkyl ether sulfate and fatty acid alkanol amide in a weight ratio of 2:1 was used, and various water-soluble metal salts as indicated in Table 1 were added thereto, thereby preparing lubricity regulating liquids. In the respective Examples, the water-soluble metal salt concentrations were defined as 6 types: 0.0025, 0.005, 0.01, 0.03, 0.07 and 0.20 (mol/L).

Comparative Examples 1 to 8

[0044] In Comparative Examples 1 to 8, no water-soluble metal salt was added (namely, all of Comparative Examples 1 to 8 have the same composition). In the other respects, they were similar to Examples 1 to 8, and thus are not explained herein.

TABLE-US-00001 TABLE 1 Composition of lubricity regulating liquid Water-soluble metal salt* Surfactant Distilled water Example 1 NaCl 320 mg Distilled water 1 L Example 2 KCl 320 mg Distilled water 1 L Example 3 MgCl.sub.26H.sub.2O 320 mg Distilled water 1 L Example 4 CaCl.sub.22H.sub.2O 320 mg Distilled water 1 L Example 5 Al.sub.2(SO.sub.4).sub.314-18H.sub.2O 320 mg Distilled water 1 L Example 6 FeCl.sub.36H.sub.2O 320 mg Distilled water 1 L Example 7 MgCl.sub.26H.sub.2O + NaCl 320 mg Distilled water 1 L (molar composition ratio 1:1) Example 8 CH.sub.3CO.sub.2Na 320 mg Distilled water 1 L *The water-soluble metal salt concentrations were defined as 6 types: 0.0025, 0.005, 0.01, 0.03, 0.07 and 0.20 (mol/L).

<Evaluation>

[0045] Tests for evaluating the lubricity and adhesiveness of the lubricity regulating liquids of Examples 1 to 8 and Comparative Examples 1 to 8 as described above to silicone rubber were conducted. The evaluating methods are as follows.

[0046] Lubricity Evaluating Test

[0047] A Silicone tube (tradename: LABORAN SILICONE TUBE manufactured by AS ONE Corporation) having an internal diameter of 3 mm was provided. As shown in FIG. 1, a silicone tube 12 was wound, three times, around a cylindrical pipe 11 made of a transparent acrylic resin having a diameter of 7 cm to be fixed thereon, thereby providing a pseudo blood vessel model 10 of which both ends were protruded and extended. A catheter 20 (manufactured by Chaperone Co., thickness: 6.0 F (2.0 mm ) was manually inserted, with constant force, from one end side of the silicone tube 12, so that the catheter 20 entered the silicone tube while rotating. Further, the catheter 20 continued to be inserted until it could not resist the frictional resistance and therefore stopped. The rotation angle at a position where the catheter 20 stopped was measured, and this angle was defined as an index of lubricity. Measurement was carried out a plurality of times.

[0048] Adhesiveness Evaluating Test

[0049] Further, the catheter 20 was retained as it was for about 10 seconds at a position where it stopped, and thereafter pulled in a direction where the catheter 20 would retract. The case where it could be easily pulled out was evaluated as no adhesion and the case where it could not be easily pulled out was evaluated as adhesion. Measurement was carried out three times. Even if adhesion occurred, the catheter 20 could be pulled out by quickly repeating the application of force toward the entering direction and force toward the retracting direction to the catheter 20.

[0050] Table 2 indicates the results on the rotation angle and the presence or absence of adhesion for Examples 1 to 8 and Comparative Examples 1 to 8 as described above (the cases where the metal salt concentration is 0 in this table correspond to Comparative Examples 1 to 8). FIG. 2 indicates a graph showing the relation between the rotation angle and the metal salt concentration.

TABLE-US-00002 TABLE 2 Example 1 Concentration of NaCl (mol of NaCl/1 L of distilled water) 0 0.0025M 0.005M 0.01M 0.03M 0.07M 0.2M Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- angle () sion* angle () sion* angle () sion* angle () sion* angle () sion* angle () sion* angle () sion* 1st 540 420 600 + 570 440 690 720 2nd 360 420 630 450 570 720 720 3rd 420 + 540 480 450 510 720 720 Average 440 460 570 490 507 710 720 Example 2 Concentration of KCl (mol of KCl/1 L of distilled water) 0 0.0025M 0.05M 0.01M 0.03M 0.07M Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation angle () sion* angle () sion* angle () sion* angle () sion* angle () sion* angle () Adhesion* 1st 420 540 510 690 690 730 2nd 510 630 630 710 710 690 3rd 390 630 690 670 710 720 Average 440 600 610 690 703 713 Example 3 Concentration of MgCl.sub.2 (mol of MgCl.sub.2/1 L of distilled water) 0 0.0025M 0.005M 0.01M 0.03M 0.07M Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation angle () sion* angle () sion* angle () sion* angle () sion* angle () sion* angle () Adhesion* 1st 460 + 690 710 700 810 810 2nd 410 660 700 720 730 750 3rd 390 670 690 750 730 750 Average 420 673 700 723 757 770 Example 4 Concentration of CaCl.sub.2 (mol of CaCl.sub.2/1 L of distilled water) 0 0.0025M 0.005M 0.01M 0.03M 0.07M Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation angle () sion* angle () sion* angle () sion* angle () sion* angle () sion* angle () Adhesion* 1st 420 690 700 720 720 780 2nd 390 720 780 690 720 720 3rd 450 700 720 700 730 690 Average 420 703 733 703 723 730 Example 5 Concentration of Al.sub.2(SO.sub.4).sub.2 (mol of Al.sub.2(SO.sub.4).sub.2/1 L of distilled water) 0 0.0025M 0.005M 0.01M 0.03M 0.07M Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation angle () sion* angle () sion* angle () sion* angle () sion* angle () sion* angle () Adhesion* 1st 360 + 690 720 780 810 810 2nd 360 690 690 780 810 810 3rd 390 720 720 780 810 840 Average 700 710 780 810 820 Example 6 Concentration of FeCl.sub.3 (mol of FeCl.sub.3/1 L of distilled water) 0 0.0025M 0.005M 0.01M 0.03M Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Rotation angle () sion* angle () sion* angle () sion* angle () Adhesion* angle () Adhesion* 1st 390 720 750 750 720 2nd 330 + 720 720 720 720 3rd 450 + 720 720 690 690 Average 390 720 730 720 710 Example 7 Concentration of MgCl.sub.2 and NaCl (mol of MgCl.sub.2 and NaCl/1 L of distilled water) (molar number of MgCl.sub.2:molar number of NaCl = 1:1) 0 0.0025M 0.005M 0.01M 0.03M 0.07M Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation angle () sion* angle () sion* angle () sion* angle () sion* angle () sion* angle () Adhesion* 1st 320 690 670 750 690 780 2nd 370 700 690 720 700 780 3rd 360 780 690 720 720 760 Average 350 723 683 730 703 773 Example 8 Concentration of CH.sub.2CO.sub.2Na (mol of CH.sub.2CO.sub.2Na/1 L of distilled water) 0 0.0025M 0.005M 0.01M 0.03M 0.07M 0.10M Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- angle () sion* angle () sion* angle () sion* angle () sion* angle () sion* angle () sion* angle () sion* 1st 210 480 480 570 690 720 870 2nd 210 450 510 600 690 780 780 3rd 210 480 510 660 720 810 810 Average 210 470 500 610 700 770 820 *[+] . . . Adhesion occurred. [] . . . No adhesion occurred. [] . . . Judgement could not be made.

[0051] As shown in FIG. 2, in Examples 1 to 8, the rotation angle was drastically raised by adding the water-soluble metal salts even though the surfactant concentration was constant. The rotation angle rose as the amount of the water-soluble metal salts (NaCl, KCl, MgCl.sub.2, CaCl.sub.2, Al.sub.2(SO.sub.3), FeCl.sub.3, MgCl.sub.2+NaCl, CH.sub.3COONa) to be added was increased, and became an almost constant value at a water-soluble metal salt concentration of 0.005 mol/L or more. From the above results, it has been found that the lubricity of the silicone rubber surface drastically improves due to the use of the surfactant and the water-soluble metal salt in combination.

[0052] Also, as indicated in Table 2, adhesion occurred in some cases (adhesion occurred four times in twenty four measurements) in the case where no water-soluble metal salt was added to the surfactant (i.e., in Comparative Examples 1 to 8), whereas no adhesion occurred in the case where the water-soluble metal salt was added in an amount of 0.0025 mol/L or more.

Examples 9 to 13

[0053] In Examples 9 to 13, the water-soluble metal salt used was magnesium chloride in all the cases, and it was mixed with various surfactants to prepare lubricity regulating liquids (see Table 3). The surfactant concentrations of the prepared solutions were defined as 0, 0.00005, 0.000075, 0.0001, 0.0002, 0.0004, 0.0005, 0.00075, 0.001, 0.002 and 0.004 (mol/L) for the respective Examples.

Example 16 and Comparative Examples 10 to 13

[0054] In Example 16 and Comparative Examples 10 to 13, no magnesium chloride was added, and they were similar to Examples 9 to 13 in the other respects (see Table 3).

TABLE-US-00003 TABLE 3 Lubricity regulating liquid Distilled water Surfactant MgCl.sub.26H.sub.2O Example 9 Distilled water 1 L Trimethylstearylammonium chloride 0.61 g Example 16 Distilled water 1 L Trimethylstearylammonium chloride Not added Example 10 Distilled water 1 L Sodium lauryl sulfate (anionic) 0.61 g Comparative Distilled water 1 L Sodium lauryl sulfate (anionic) Not added Example 11 Distilled water 1 L Sodium 1-dodecanesulfonate (anionic) 0.61 g Comparative Distilled water 1 L Sodium 1-dodecanesulfonate (anionic) Not added Example 12 Distilled water 1 L Myristyl sulfobetaine (zwitterionic) 0.61 g Comparative Distilled water 1 L Myristyl sulfobetaine (zwitterionic) Not added Example 13 Distilled water 1 L Tween 20 (nonionic) 0.61 g Comparative Distilled water 1 L Tween 20 (nonionic) Not added

<Evaluation>

[0055] For the lubricity regulating liquids of Examples 9 to 13, Example 16 and Comparative Examples 10 to 13, the evaluation results on lubricity are shown in FIGS. 3 and 6, and those of adhesiveness are shown in Table 4. In the meantime, a LABORAN SILICONE TUBE having an internal diameter of 3 mm (manufactured by AS ONE Corporation) was employed as the silicone tube used in the evaluation of lubricity.

TABLE-US-00004 TABLE 4 Concentration of surfactant (mmol/L) 0 0.05 0.075 0.1 0.2 0.4 0.75 1 2 4 Example 9* + Example 16* + Example 10 + Comparative + + Example 11 + Comparative + + + + + Example 12 + Comparative + Example 13* + Comparative + + + Adhesion No adhesion *The catheter insertion resistance is Example 9 < Example 16, Example 13 < Comparative Example 13.

[0056] In Examples 9 and 16 using a cationic surfactant trimethylstearylammonium chloride, Example 9 in which magnesium chloride was added was superior to Example 16 in which no magnesium chloride was added in terms of the lubricity at a low surfactant concentration of 0.2 mmol/L or less, as shown in FIG. 3. As regards adhesiveness, no adhesion occurred at a surfactant concentration of 0.05 mmol/L or more in either Examples 9 and 16. However, the feeling of resistance at the time of catheter insertion in Example 9 was apparently smaller than that in Example 16, and it has been found that the coexistence of magnesium chloride and a cationic surfactant enabled quite smooth insertion of a catheter.

[0057] In Examples 10 and 11 and Comparative Examples 10 and 11 using an anionic surfactant, Examples 10 and 11 in which magnesium chloride was added were superior, in terms of lubricity, to Comparative Examples 10 and 11 in which no magnesium chloride was added, as shown in FIG. 4. As regards adhesiveness, no adhesion occurred at a surfactant concentration of 0.05 mmol/L or more in Examples 10 and 11, whereas adhesion occurred at a surfactant concentration of 0.05 mmol/L or less in Comparative Example 10 and at a surfactant concentration of 0.2 mmol/L or less in Comparative Example 11. In view of the above, it has been found that the coexistence of an anionic surfactant and magnesium chloride improved both lubricity and non-adhesiveness.

[0058] Further, in Example 12 and Comparative Example 12 using a zwitterionic (betaine-type) surfactant, Example 12 in which magnesium chloride was added was superior, in terms of lubricity, to Comparative Example 12 in which no magnesium chloride was added, as shown in FIG. 5. As regards adhesiveness, no adhesion occurred at a surfactant concentration of 0.05 mmol/L or more in Example 12 and Comparative Example 12, as indicated in Table 4 above. In view of the above, it has been found that the coexistence of a zwitterionic (betaine type) surfactant and magnesium chloride improved both lubricity and non-adhesiveness.

[0059] Also, in Example 13 and Comparative Example 13 using a nonionic surfactant, both Example 13 and Comparative Example 13 exhibited excellent lubricity.

[0060] As regards adhesiveness, adhesion occurred at a surfactant concentration of 0.05 mmol/L or less in Comparative Example 13, whereas no adhesion occurred at a surfactant concentration of 0.05 mmol/L or more in Example 13, as indicated in Table 4 above. Further, the feeling of resistance at the time of catheter insertion in Example 13 was apparently smaller than that in Comparative Example 13, and it has been found that the coexistence of magnesium chloride and a nonionic surfactant enabled quite smooth insertion of a catheter.

Example 14

[0061] In Example 14, prepared was a solution mixture containing 500 ml of distilled water, 1 ml of a commercial kitchen detergent (mixture of anionic surfactant+nonionic surfactant: concentration: 16% by weight) and a commercially-available bittern solution (Aranami no Honnigari, manufactured by AKO ARANAMI SHIO CO., LTD.; 100 ml of this bittern solution contains 4318 mg of magnesium, 3810 mg of potassium, 3048 mg of sodium and 2032 mg of calcium). This solution mixture was used as a lubricity regulating liquid. The bittern concentrations were defined as 0, 0.25, 5, 10 and 15 (ml per liter of distilled water). The lubricity and adhesiveness were respectively evaluated by the methods for evaluating lubricity and adhesiveness as described above. In the meantime, a LABORAN SILICONE TUBE having an internal diameter of 3 mm (manufactured by AS ONE Corporation) was employed as the silicone tube used in the evaluation of lubricity.

Comparative Example 14-1

[0062] In Comparative Example 14-1, a liquid comprising no bittern but similar to that prepared in Example 14 in the other respects was employed as the lubricity regulating liquid.

Comparative Example 14-2

[0063] In Comparative Example 14-2, a liquid comprising no surfactant but similar to that prepared in Example 14 in the other respects was employed as the lubricity regulating liquid.

<Evaluation>

[0064] The evaluations of lubricity and adhesiveness for Example 14, Comparative Example 14-1 and Comparative Example 14-2 are indicated in Tables 5 to 7. The graphs concerning lubricity are shown in FIGS. 7 to 9. In the meantime, a LABORAN SILICONE TUBE having an internal diameter of 3 mm (manufactured by AS ONE Corporation) was employed as the silicone tube used in the evaluation of lubricity.

TABLE-US-00005 TABLE 5 Various concentrations of bittern + 1 ml of commercially-available kitchen detergent + 500 ml of distilled water Amount of bittern added (ml) 0 0.25 ml 5 ml 10 ml 15 ml Rotation Rotation Rotation Rotation Rotation angle () Adhesion* angle () Adhesion* angle () Adhesion* angle () Adhesion* angle () Adhesion* 1st 390 510 600 780 780 2nd 420 540 660 810 810 3rd 600 510 660 780 810 4th 360 630 690 810 810 5th 360 630 720 810 810 6th 360 + 680 690 810 780 7th 420 690 720 750 840 8th 400 + 630 720 720 750 9th 400 600 690 720 810 10th 360 + 540 690 750 630 11th 390 + 660 690 770 660 12th 360 + 630 670 700 720 Average 402 604 683 768 768 + Adhesion occurred. No adhesion occurred.

TABLE-US-00006 TABLE 6 Various concentrations of commercially-available kitchen detergent + 500 ml of distilled water. Amount of commercial kitchen detergent added (ml) 0 0.5 ml 1 ml 2 ml 3 ml 4 ml Rotation Rotation Rotation Rotation Rotation Rotation angle () Adhesion* angle () Adhesion* angle () Adhesion* angle () Adhesion* angle () Adhesion* angle () Adhesion* 1st 0 + 180 + 390 480 480 450 2nd 0 + 240 + 420 450 600 600 3rd 0 + 240 + 600 600 660 690 4th 0 + 270 + 360 360 450 510 5th 0 + 330 + 360 420 420 690 6th 0 + 330 + 360 + 450 480 570 7th 0 + 240 + 420 510 510 450 8th 0 + 210 + 400 + 510 510 450 9th 0 + 270 + 400 310 + 400 + 450 10th 0 + 240 + 360 + 400 + 400 400 11th 0 + 270 390 + 480 350 450 12th 0 + 300 360 + 400 390 420 Average 0 260 402 464 471 511 *[+] . . . Adhesion occurred. [] . . . No adhesion occurred. [] . . . Judgement could not be made.

TABLE-US-00007 TABLE 7 500 ml of Distilled water + bittern. Amount of bittern added (ml) 0 0.25 ml 5 ml 10 ml 15 ml Rotation Rotation Rotation Rotation Rotation angle () Adhesion* angle () Adhesion* angle () Adhesion* angle () Adhesion* angle () Adhesion* 1st 0 + 30 60 30 30 2nd 0 + 60 60 30 60 3rd 0 + 30 60 30 + 30 4th 0 + 30 + 30 30 40 + 5th 0 + 30 + 30 30 + 40 + 6th 0 + 50 + 30 20 40 + 7th 0 + 40 + 20 20 30 8th 0 + 10 + 0 30 20 9th 0 + 30 + 30 + 10 10 10th 0 + 30 40 + 30 30 11th 0 + 40 + 0 10 40 + 12th 0 + 30 20 + 10 30 Average 0 33 25 5 33 + Adhesion occurred. No adhesion occurred.

[0065] Evaluation Results on Lubricity

[0066] As shown in FIG. 7 and Table 5, in Example 14, the addition of bittern to the solution mixture of distilled water and a commercially-available kitchen detergent as the lubricity regulating liquid drastically raised the rotation angle as compared with that before addition. Further, the rotation angle rose as the amount of the bittern added was increased, and became a constant value when the bittern concentration reached a certain level. The maximum value of the rotation angle was 768.

[0067] In Comparative Example 14-1 in which no bittern was added, as shown in FIG. 8 and Table 6, the rotation angle rose as the amount of the commercially-available kitchen detergent added was increased, and became a constant value when the commercially-available kitchen detergent concentration reached a certain level. However, the maximum value of the rotation angle was 511, which was significantly lower than the maximum value 768 for the rotation angle in Example 14 in which bittern was added to the solution mixture.

[0068] Further, in Comparative Example 14-2 in which no surfactant was added, as shown in FIG. 9 and Table 7, lubricity was quite poor so that the catheter could hardly be inserted.

[0069] Evaluation Results on Adhesiveness

[0070] In Example 14, no adhesion occurred as indicated in Table 5. On the other hand, in Comparative Example 14-1, adhesion occurred when the surfactant concentration was not a certain value or more as indicated in Table 6. Further, in Comparative Example 14-2, adhesion occurred in some cases even when the bittern concentration was increased as indicated in Table 7.

[0071] From the above results, it has been found that a lubricity regulating liquid containing a surfactant and bittern in combination could improve the lubricity of a silicone rubber surface and prevent an adhesion phenomenon.

[Evaluation of Various Kinds of Silicone Rubber]

[0072] As Example 15, there was prepared a lubricity regulating liquid consisting of a solution mixture of 1 L of distilled water, 0.29 g of sodium lauryl sulfate (0.001 mol/L) and magnesium chloride (hexahydrate). The concentrations of magnesium chloride in the lubricity regulating liquid were defined as 0, 0.0025, 0.005, 0.01, 0.03, 0.07 and 0.20 (mol per liter of distilled water).

[0073] The lubricity regulating liquid of Example 15 was used to evaluate the lubricity and adhesiveness of the following two kinds of silicone rubber.

[0074] Silicone rubber (1): LABORAN SILICONE TUBE having an internal diameter of 3 mm (AS ONE Corporation)

[0075] Silicone rubber (2): silicone tube obtained by coating an inner wall of a LABORAN SILICONE TUBE having an internal diameter of 6 mm (AS ONE Corporation) with ELASTOSILM8520 (manufactured by WACKER ASAHIKASEI SILICONE CO., LTD.) at a thickness of 1.5 mm

(Evaluation)

[0076] The evaluations of lubricity and adhesiveness for silicone rubber (1) and silicone rubber (2) are indicated in Table 8. The evaluation of lubricity is shown in FIG. 10.

TABLE-US-00008 TABLE 8 Silicone rubber (1) Only distilled water (no sodium lauryl sulfate or Concentration of MgCl.sub.26H.sub.2O (mol of MgCl.sub.26H.sub.2O/1 L of distilled water) MgCl.sub.2) 0 0.0025M 0.005M 0.01M 0.03M 0.07M 0.20M Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- angle () sion* angle () sion* angle () sion* angle () sion* angle () sion* angle () sion* angle () sion* angle () sion* 1st 90 + 220 + 210 + 270 420 560 720 690 2nd 90 + 240 + 260 + 290 330 560 720 750 3rd 60 + 220 + 250 + 280 + 330 620 770 790 Average 87 227 240 280 360 580 737 743 Silicone rubber (2) Only distilled water (no sodium lauryl sulfate on Concentration of MgCl.sub.26H.sub.2O (mol of MgCl.sub.26H.sub.2O/1 L of distilled water) MgCl.sub.2) 0 0.0025M 0.005M 0.01M 0.03M 0.07M Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation Adhe- Rotation angle () sion* angle () sion* angle () sion* angle () sion* angle () sion* angle () sion* angle () Adhesion* 1st 30 120 60 330 + 410 770 990 2nd 30 100 90 360 330 810 1040 3rd 30 100 120 310 330 810 1020 Average 30 107 90 333 357 797 1017 *[+] . . . Adhesion occurred. [] . . . No adhesion occurred. [] . . . Judgement could not be made.

[0077] Evaluation Results on Lubricity

[0078] As indicated in Table 8 and FIG. 10, it has been found that, as regards both silicone rubber (1) and silicone rubber (2), the rotation angle, i.e., lubricity, was drastically increased as the amount of magnesium chloride added was increased. In view of the above, the effectiveness of silicone rubber for lubricity regardless of its kind has been strongly supported.

[0079] Evaluation Results on Adhesiveness

[0080] As indicated in Table 8, it has been found that, as regards both of silicone rubber (1) and silicone rubber (2), no adhesion phenomenon occurred as the amount of magnesium chloride added was increased. In view of the above, the effectiveness of silicone rubber also for adhesion phenomenon regardless of its kind has been strongly supported.

[0081] As indicated in the evaluation results on silicone rubber (1) and silicone rubber (2) described above, the silicone rubber to be applied to the lubricity regulating liquid according to the present invention is not particularly limited so long as it is rubber having a siloxane skeleton in the basic skeleton. Specific examples of such silicone rubber include:

[0082] ELASTOSIL N 2010, ELASTOSIL N 2034, ELASTOSIL N 2189, ELASTOSIL N 2197, ELASTOSIL N 9132S, ELASTOSIL RT K, WACKER SilGel 612, ELASTOSIL RT 601, ELASTOSIL RT 602, ELASTOSIL RT 604, ELASTOSIL RT 607, ELASTOSIL RT 741, ELASTOSIL RT 745, ELASTOSIL RT 745 S, ELASTOSIL RT 707 W, ELASTOSIL RT 713, SEMICOSIL 987 GR, SEMICOSIL 988/1K, SEMICOSIL 989/1K and ELASTOSIL M8520 (all manufactured by WACKER ASAHIKASEI SILICONE CO., LTD.), and

[0083] LABORAN SILICONE TUBE (manufactured by AS ONE Corporation).

[0084] The reagents used in Examples and Comparative Examples are listed below. [0085] Sodium chloride (99% or more; manufactured by The Salt Industry Center of Japan) [0086] Potassium chloride (99% or more; manufactured by Naitou Shouten Co., Ltd.) [0087] Magnesium chloridehexahydrate (99% or more; manufactured by Naitou Shouten Co., Ltd.) [0088] Calcium chloride (manufactured by Naitou Shouten Co., Ltd.) [0089] Aluminum sulfate tetradecahydrate-octadecahydrate (manufactured by Wako Pure Chemical Industries Ltd.) [0090] Ferric chloridehexahydrate (manufactured by Wako Pure Chemical Industries Ltd.) [0091] Trimethylstearylammonium chloride (manufactured by Tokyo Chemical Industry Co., Ltd.) [0092] Sodium lauryl sulfate (manufactured by Tokyo Chemical Industry Co., Ltd.) [0093] Sodium 1-dodecanesulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.) [0094] Myristyl sulfobetaine (manufactured by Tokyo Chemical Industry Co., Ltd.) [0095] Tween 20 (manufactured by Tokyo Chemical Industry Co., Ltd.) [0096] Bittern (Aranami no Honnigari manufactured by AKO ARANAMI SHIO CO., LTD.)

<Application to Blood Vessel Model Made of Silicone Rubber>

[0097] A blood vessel model made of silicone rubber is incorporated into a case for a human model provided by the Applicant, and a tank, piping and a pump are attached thereto as auxiliary devices. Into the tank, 10 l of tap water was put, and 300 ml of a bittern solution was further injected. One hundred (100) ml of this bittern solution contains 4318 mg of magnesium, 3810 mg of potassium, 3048 mg of sodium and 2032 mg of calcium. To a reference liquid obtained by mixing a predetermined amount of bittern to water, 40 ml of a surfactant used in Example 1 described above is added. The amount of a surfactant to be added can be preferably regulated by users depending on their preference.

[0098] A pigment, a bactericide, a preservative and other aids can be added to a circulating liquid according to need. When such a circulating liquid is used, the evaluation that the feeling of insertion of a catheter into the blood vessel model is close to that at the time of an operation was obtained from a plurality of doctors.

[0099] More specifically, the catheter could be inserted, without resistance, even into a meandering portion of the blood vessel model, and no adhesion occurred therebetween even when the catheter was inserted into the blood vessel model and left as it was.

[0100] The present invention is not limited to the above embodiments and Examples of the invention. Various modified embodiments are also encompassed within the scope of the present invention, so long as they would be obvious to those skilled in the art without departing from the scope of claims.

EXPLANATION OF REFERENCE NUMERALS

[0101] 10. Pseudo blood vessel model [0102] 11. Cylindrical pipe [0103] 12. Silicone tube [0104] 20. Catheter