JPH0226496B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of the Invention) The present invention aims to improve the propagation of ultrasound energy between the skin and an ultrasound diagnostic probe (hereinafter abbreviated as a probe) when using an ultrasound diagnostic device. The present invention relates to a transparent viscous composition for ultrasonic diagnosis that is applied to and interposed in the skin. (Prior Art) Conventional ultrasonic diagnostic compositions, in the form of pastes, tend to flow due to skin temperature when they are in contact with the skin for a long period of time, and salting out occurs in the composition due to sweating, causing the composition to turn into a liquid. In many cases, the composition is difficult to stay fixed between the probe and the skin, and a gap is formed, which tends to create an air layer, which often impairs the propagation of ultrasonic energy. In addition, highly viscous gel-like materials have good adhesion to the skin and probe, but air bubbles that are mixed in during manufacturing or application are difficult to remove, and air layers (bubbles) may also be present. This method has disadvantages such as making it impossible to obtain accurate diagnostic information with good reproducibility as a result of poor propagation of ultrasonic energy. Furthermore, the highly viscous gel-like material is extremely sticky, making it inconvenient to use, causing discomfort to the patient, and making it difficult to remove after use. (Objective of the Invention) The present invention improves all the above-mentioned drawbacks, and aims to fix the probe and the skin, have appropriate adhesion, and provide ultrasonic energy to the skin. It is stable against body temperature and perspiration, retains moisture for a long time without creating viscosity, prevents the formation of air spaces, does not cause skin irritation, and is easy to remove after use. The object of the present invention is to provide a transparent viscous composition for ultrasonic diagnosis that has excellent storage stability. (Structure of the Invention) That is, the transparent viscous composition for ultrasound diagnosis of the present invention is made by blending a carboxyvinyl polymer salt, hydroxyethyl cellulose, disodium phosphate, monopotassium phosphate, polyhydric alcohol, and water. This is a characteristic feature. (Description of the specific structure of the invention) The carboxyvinyl polymer salt used in the present invention is a free acid type carboxyvinyl polymer (for example, Carbopol 940 manufactured by Gudrich Co., Ltd. in the United States).
etc.) and a basic substance such as caustic soda, caustic potash, or alkanolamine. The preferred basic substance is caustic soda or caustic cal. of aqueous solutions of carboxyvinyl polymer salts
PH value is 5-8. The amount of the salt of the carboxyvinyl polymer is 0.4 to 1.2% by weight, preferably 0.5 to 1.0% by weight, based on the total amount of the composition. If it is less than 0.4% by weight, it becomes a liquid (does not form the desired viscous substance), and it is difficult to flow and stay fixed between the skin and the probe, and an air layer is likely to be formed. 1.2% by weight
If the amount exceeds 1, the viscosity becomes high, making it difficult to adhere to any part of the human body such as a flat or curved surface without gaps, and also extremely difficult to remove after use. Hydroxyethyl cellulose is, for example, Cellosize WP- manufactured by Union Carbide Company, USA.
4400M, A5000F manufactured by Fuji Chemical Co., etc. are sufficient, and those having a viscosity of 4000 to 6000 CPS (Bruckfield rotational viscometer, measurement temperature 25° C., 2% aqueous solution by weight) are suitable. Hydroxyethylcellulose is blended in order to improve the unique gel-like (pudding-like) viscosity exhibited by the above-mentioned carboxyvinyl polymer so as to meet the purpose of the present invention, and the composition of the present invention maintains transparency. However, when applied between the probe and the skin, it has an appropriate extensibility (fluidity) and is interposed between the probe and the skin to exhibit the effect of maintaining continuous adhesion. Furthermore, hydroxyethyl cellulose is non-ionic, extremely stable against salts, and has excellent acid resistance and alkali resistance. Unlike other carboxymethyl celluloses, it does not gel (purine-like) like sodium alginate and has the property of being resistant to spoilage. The blending amount of hydroxyethylcellulose is 0.08~
0.8% by weight, preferably 0.05-0.6% by weight.
If it is less than 0.03% by weight, the above effects cannot be achieved, and if it is more than 0.8% by weight, the composition will decrease in transparency and become highly viscous, making it impossible to obtain appropriate extensibility (elongation). The mixing ratio of disodium phosphate and monopotassium phosphate is 1:0.2 to 6.0, and the total amount of both is 0.2 to 6.0.
It is blended in an amount of 2.5% by weight (preferably 0.4 to 2.0% by weight). When the amount is less than the above minimum limit, the pH buffering effect is reduced and the storage stability of the composition is likely to deteriorate. Also, if the amount exceeds the maximum limit,
A salting-out phenomenon occurs, causing opacity and water separation, and storage stability is likely to deteriorate. The polyhydric alcohol may be at least one type selected from the group consisting of glycerin, diglycerin, propylene glycol, dipropylene glycol, 1.3-butylene glycol, and polyethylene glycol, and its blending amount is 10 to 10% based on the total amount of the composition. It is 80% by weight. The type of polyhydric alcohol is not particularly limited, but particularly preferably one pair of glycerin and propylene glycol is used.
The total amount of both is 18-25% by weight with a ratio of 0.5-1.5
It is blended with. When the amount of polyhydric alcohol is less than 10% by weight, the composition tends to dry, the adhesion between the probe and the skin is reduced, and the propagation of ultrasound energy may be attenuated. If this happens, the transparency will decrease and the storage stability will also deteriorate. The amount of water blended is 60 to 85% by weight, preferably 65 to 80% by weight, and 60% by weight based on the total amount of the composition.
It is difficult to obtain a composition that achieves the object of the present invention even with less than 85% by weight or even with more than 85% by weight.
The viscosity of the composition is preferably adjusted to 20,000 to 250,000 CPS (measured by the method described in Examples). The present invention will be explained below with reference to Examples. (1) Appearance, (2) Storage stability, (3) Viscosity, (4) Practical property tests (drying resistance (water retention), sweating resistance, adhesion, attenuation of ultrasonic energy propagation) described in Examples , skin irritation] was investigated using the following method. (1) Appearance A sample that was transparent at a temperature of 10 to 45°C was considered transparent. (2) Storage stability After storing the samples for 3 months in a constant temperature room where the temperature is changed repeatedly between -10℃ and 45℃ every 2 weeks, those with a transparent appearance and no separation of water are considered stable, and the others are considered unstable. Stable. (3) Viscosity The temperature of the sample was set to 30℃, and a Burckfield viscometer (Bismetron US manufactured by Seiki Kogyo Kenkyusho) was used.
-Al type, rotor No. 4, rotation speed 8r・p・m)
The unit was measured in centipoise (CPS). (4) Practical characteristics A practical characteristics test for ultrasound diagnosis was conducted on 20 test subjects for each sample, with the sample interposed between the probe and the skin for 15 minutes in close contact. We investigated the following items. Drying resistance (water retention) and sweat resistance: Does part of the sample flow during the measurement time?
It is expressed as the number of people who experienced dry air. Adhesion is indicated by the number of people in whom an air space was created due to the intervening sample flowing when the contact surface between the probe and the skin was inclined (80°C). Attenuation of ultrasound energy propagation: There were air bubbles in the sample, or the sample moved or dried during the measurement period, reducing the clarity of the image displayed on the TV. Shown in number of people. Skin irritation The number of people who felt irritation on their skin during the measurement, or who had skin irritation such as red spots or edema on their skin after the measurement was completed and the sample was removed. Examples 1 to 8, Comparative Examples 1 to 8 (1) Composition

[Table] (2) Preparation method After dispersing Carbopol 940 in a mixture of propylene glycol and glycerin in the remaining amount of water, add the cello size prepared in advance.
Inject the aqueous solution of WP-4400M and stir to mix. Next, an aqueous solution of caustic soda is injected and stirred and mixed uniformly to generate a neutralized salt in which Carbopol 940 is neutralized with caustic soda. Subsequently, aqueous solutions of disodium phosphate, monopotassium phosphate, methylparaben, and Blue No. 1 were injected, and the total amount was uniformly stirred and mixed for adjustment. (3) Characteristics As shown in Table 1, the composition of Comparative Example 1 was gel-like (pudding-like) and had poor practical properties.
This was improved by adding hydroxyethyl cellulose, and although 2 out of 20 test subjects found it somewhat difficult, there were no problems in practical use. In addition, Comparative Example 2 had a high viscosity,
If air bubbles were mixed in, it was difficult to remove them and good results could not be obtained. Examples 4-5, Comparative Examples 4-7 (1) Composition

[Table] Note) * However, the caustic potash is the same as the caustic soda in Example 1.
(2) Adjustment method Adjustment is performed in the same manner as in Example 1. (3) Characteristics As shown in Table 1, Example 4 was a little dry, which caused some difficulty for two people, but practically no problems were observed. Furthermore, in Example 5, mild erythema was observed in only one patient, but the level was sufficient for practical use. Comparative Example contains less phosphoric acid salts and has disadvantages in sweat resistance, Comparative Example 5 contains more salts and the transparency and viscosity of the composition decreases, resulting in poor adhesion, and Comparative Example 6 contains polyhydric alcohol. The amount of polyhydric alcohol was small and the drying resistance was poor, whereas in Comparative Example 7, the amount of polyhydric alcohol blended was excessive and skin irritation was observed.

【table】

[Table] (Effects of the Invention) As described above, it is clear that the present invention provides a transparent viscous composition for ultrasonic diagnosis which can be applied to ultrasonic diagnostic equipment and has improved all the conventional drawbacks. That is, the composition of the present invention is a transparent composition and has an appropriate viscosity, thereby preventing air bubbles from being mixed in, making it easy to apply to the probe and the skin, and maintaining continuous close contact between the probe and the skin. , has the effect of maintaining the propagation of ultrasonic energy well. In addition, it is an excellent transparent viscous composition for ultrasonic diagnosis with good storage stability and no skin irritation.

Claims (1)

[Scope of Claims] 1. A transparent viscous composition for ultrasound diagnosis, comprising the following components (A) to (E). (A) Salt of carboxyvinyl polymer; 0.4-1.2% by weight (B) Hydroxyethyl cellulose; 0.03-0.8% by weight (C) Polyhydric alcohol; 10-30% by weight (D) Disodium phosphate and monopotassium phosphate (weight ratio 1:0.2-6.0); 0.2-2.5% by weight (E) Water