JPH0466451B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a patch, particularly a patch called a patch or plaster, which uses a patch base containing almost no water. [Prior art] Plastering agents use polymers such as natural rubber or synthetic rubber with relatively low water content as a base material. As is clear from the literature (for example, "Pharmaceutical Engineering Handbook" edited by Masayasu Sugihara et al., 30th edition, p. 228), the manufacturing method includes steps such as primary kneading and secondary kneading, and is spread onto a support such as flannel, nonwoven fabric, or plastic film. In the spreading process, methods such as spreading using a solvent or heating and pressing are used. As described above, the method for producing plaster is very complicated and requires a great deal of time and effort. Therefore, the present inventors conducted intensive research to find an excellent plaster base that does not have the above-mentioned drawbacks, etc., and found that ethylene-vinyl acetate copolymer resin met the purpose. Application No. 59-119440 (Japanese Unexamined Patent Publication No. 61-5012)). [Problems to be solved by the invention] However, since ethylene vinyl acetate copolymer resin softens and its viscosity decreases when heated, it does not have the advantage of being easy to spread thinly on a support. However, at room temperature, it was stiff and had a bad feel to the skin, and was not very satisfactory. [Means for Solving the Problems] Under these circumstances, the present inventors have conducted further research and found that blending a specific polyoxyethylene alkyl phenyl ether with ethylene vinyl acetate copolymer resin causes the above-mentioned stiff feeling. It is possible to obtain a patch that has improved adhesiveness and fits comfortably on the skin, and that this is used as the first layer (skin contact layer), and this is coated with a low-adhesive ethylene vinyl acetate copolymer resin or a polyoxyethylene alkyl film. We discovered that by laminating a second layer containing enyl ether, we could obtain an excellent adhesive patch that was more flexible and did not cause bleeding or smearing than those using conventional supports. Completed the invention. That is, in the present invention, the vinyl acetate content is 15 to 50
Melt index in weight% is 30-500g/10
A first aspect of the present invention relates to a patch characterized in that it uses a base material containing 100 parts by weight of an ethylene vinyl acetate copolymer resin with an HLB of 3 to 10 and 10 to 50 parts by weight of a polyoxyethylene alkyl phenyl ether with an HLB of 3 to 10. invention and 100 parts by weight of an ethylene vinyl acetate copolymer resin with a vinyl acetate content of 15 to 50% by weight and a melt index of 30 to 500 g/10 minutes and HLB3 to
a first layer using a base containing 10 to 50 parts by weight of a polyoxyethylene alkyl phenyl ether of 10;
and an ethylene vinyl acetate copolymer resin having a vinyl acetate content of 15 to 40 parts by weight and a melt index of 5 to 500 g/10 minutes, or 100 parts by weight of the ethylene vinyl acetate copolymer resin and a polyester having an HLB of 3 to 10. Oxyethylene alkyl phenyl ether 5
The present invention provides a second invention relating to a patch characterized by comprising a second layer consisting of ~40 parts by weight. Ethylene vinyl acetate copolymer resin (hereinafter referred to as
EVA (referred to as EVA) is preferably EVA having a vinyl acetate content (by saponification method) of 15 to 50 wt% and a melt index (JIS: K-6760-1966) of 30 to 500 g/10 minutes. The higher the vinyl acetate content, the better the adhesion to the skin, the lower the melting point, and the easier production, but the stronger the acetic acid odor, the more sticky the skin, and the harder it is to peel off when removed after use. When the vinyl acetate content decreases, the crystallinity of EVA increases, making it stiff and difficult to adhere to the skin. Therefore 15~
EVA of about 50wt% is preferable. EVA with a high melt index has a low cohesive force and flows easily, making it difficult to handle and making it sticky and unpleasant to use. On the other hand, when the melt index decreases, the cohesive force increases and adhesion to the skin deteriorates. Therefore, EVA having a melt index of about 30 to 500 g/10 minutes is preferable. Moreover, as polyoxyethylene alkyl phenyl ether (hereinafter referred to as PAP), one having an HLB value of 3 to 10 is preferable. If the HLB value exceeds 10, the compatibility with EVA will be poor, and PAP will deteriorate over time.
It is not preferable because it separates from EVA and has poor stability, and those below HLB3 cause skin irritation. As a preferable PAP with such HLB,
Examples include polyoxyethylene nonyl phenyl ether, polyoxyethylene octylphenyl ether, and the like. The blending ratio of EVA and PAP is the polymerization ratio of EVA
When PAP is set to 100, it is preferable that the PAP be between 10 and 50. If the PAP is less than 10, the material will have poor flexibility and stretch, giving a stiff feeling.
Also, if it exceeds 50, it will be too soft and sticky, depending on the type of EVA. If the adhesion to the skin is not sufficient due to the influence of added ingredients, etc., use polybutene, polyisobutylene,
Terpene resin, olefin resin or rosin resin [for example, ester gums manufactured by Arakawa Chemical Industry Co., Ltd.]
Adhesive properties can be adjusted by adding adhesives such as The optimum range of the combination and quantitative ratio of each of the above-mentioned components can be determined by conducting experiments depending on the purpose and the like. To prepare the patch of the first invention, the first step is to
After heating to about 150℃ to melt EVA and PAP,
The temperature may be maintained at about 70 to 130°C, and various additives such as medicinal ingredients may be added and mixed, coated on a suitable release paper or backing, and allowed to cool. Medicinal ingredients include camphor, menthol, methyl salicylate, indomethacin, ketoprofen, diclofenac, steroid hormones, nitroglycerin, anti-inflammatory drugs such as scopolamine, anti-motion sickness drugs, angina drugs, antipsychotics, etc. Ru. Normally, when such medicinal ingredients are incorporated into a patch, the solvents used to dissolve or disperse the ingredients include hydrocarbons such as liquid paraffin, petrolatum, and squalane, fats and oils such as olive oil and soybean oil, lauric acid, and myristic acid. Examples include fatty acids such as acids, but hydrocarbons are particularly preferred in the present invention. The product dissolved and mixed in this way not only does not require the commonly used kneading process, but also does not require a solvent when it is spread into a bag because the base is already dissolved. There is no need to press it, just apply it to a uniform thickness on the release paper or backing. Since the base of the present invention has the strength necessary for a patch, there is no need to use cloth or plastic as a support as in the past. However, since the back side of the surface that is adhesive to the skin is also sticky, it is preferable to have backing in order to prevent this back side from adhering to clothing or the like. Of course, flannel, nonwoven fabric, plastic film, etc., which have been conventionally used as a support, may be used for this backing, but the strength and thickness required for the support are not required, and a thin kneaded cloth is used. etc. is also sufficient. For this purpose, as in the second invention, as a backing, a polymer of the same type as the above-mentioned base material is used as the second layer. (e.g., less elasticity, better elasticity, etc.), a more excellent patch can be obtained. It is preferable that this backing is finished in such a way that it does not unnecessarily adhere to clothing, etc., and is not weaker in strength than the skin adhesive surface (layer). For this, the vinyl acetate content must be between 15 and 40, especially between 15 and 30.
Melt index in weight% is 5 to 500, especially 10
Use EVA which is ~450g/10min or use this
A mixture of 5 to 40 parts of PAP with an HLB of 3 to 10 to 100 parts of EVA is suitable, and it is preferable to appropriately select and mix materials within this range in relation to the skin adhesive surface (layer). . In addition, this patching can also be used as a drug-containing layer by mixing the same or different types of drugs to form a patch, in order to expect a combined effect or an effect of controlling release (absorption). It is also possible to do so. The two-layer adhesive patch of the second invention is prepared by heating and melting the second layer of EVA or a mixture of EVA and PAP on top of the first layer, which is formed on release paper once cooled, as described above. It is prepared by laminating materials by coating or the like. [Effects] The patch of the present invention reduces the viscosity when the base is heated, is easy to prepare, does not have a stiff feeling, and fits comfortably on the skin, and the patch with a second layer laminated has a Since it does not require a support layer like the conventional one, it has good elasticity, is easy and reliable to apply, and has the advantage of not causing bleeding or smearing. [Example] Next, an explanation will be given by giving an experimental example and an example. Experimental example 1 Vinyl acetate content 28wt%, melt index
400g/10 minutes EVA (product name Evaflex 210)
30 parts, vinyl acetate content 41wt%, melt index 65g/10 minutes EVA (each product Evaflex
40) Add 20 parts of HLB4.5 polyoxyethylenonyl phenyl ether (manufactured by Nikko Chemicals Co., Ltd., trade name Nikkol NP-2), heat to 130°C to melt, and then add ester gum [Arakawa]. Kagaku Kogyo Co., Ltd.
Add 30 parts of Ester Gum H manufactured by Ester Gum H and stir well until the mixture is evenly mixed. This was cooled while stirring, and after confirming that the temperature was below 90°C, it was applied onto a cotton cloth while stirring to give a coating amount of 250 g/m ² to obtain a patch. Experimental example 2 35 parts of Everflex 210, 40 parts of Everflex
Add 15 parts of and 5 parts of Nikkor NP-2, 130
After heating to ℃ and melting it, add ester gum H to 45℃.
Add 1 part and mix well until evenly mixed.
Cool this while stirring, confirm that the temperature is below 90℃, and apply the amount of paste on the release paper while stirring.
Spread it to a thickness of 130 g/m ² to form the first layer. Next, 46 parts of Evaflex 210, vinyl acetate content 28wt%, melt index 15g/10 min.
Add 28 parts of EVA (trade name Evaflex 250) and 26 parts of Nikkor NP-2, heat to 135°C to melt, and mix until uniform. Next, cool the mixture while stirring, confirm that the temperature is below 110°C, and apply the entire amount of plaster on top of the previous layer while stirring.
A patch was obtained by applying the mixture at a concentration of 250 g/m ² . Control example 50 parts of styrene-butadiene styrene resin (SBS resin, manufactured by Ciel Kagaku Co., Ltd., trade name CARIFLEX TR-1102) as a synthetic rubber was heated to 170°C to melt it, and then cooled with stirring to a temperature below 130°C. After confirming that the mixture had softened, 30 parts of Ester Gum H and 20 parts of liquid paraffin were added, and the mixture was spread on cotton cloth with stirring to give a patch of 250 g/m ² . Experimental Example 3 The patches obtained in Experimental Examples 1 and 2 and the control example were evaluated using the following test method. (1) Moisture permeability measurement method Place 5.0 g of anhydrous calcium chloride in a 50 ml glass bottle (diameter 1.5 cm) and seal the opening of the glass bottle with a patch. Leave the glass bottle in a constant temperature and humidity chamber at 40℃ and 90%RH for 9 days. Accurately weigh the weight increase (mg) of calcium chloride, and take the increase per day as the moisture permeability. It is said that patches with high moisture permeability do not prevent skin breathing or sweating at the patch site, and have fewer side effects. (2) Stretchability measurement method: Patch piece is 2.5 x 10 x 10 x 2.5 x 10 x 10 x 10
Measurements are made by holding a piece of paper in cm and stretching it at a pulling speed of 50 mm/min. Read the overload at 20% elongation and use the converted value per 1 cm of width as the elongation. The smaller the value, the more easily the patch stretches. (3) Skin irritation A patch measuring 3 x 4 cm was applied to the flexor sides of the left and right upper arms of 10 healthy men and women for 8 hours. The patch is then removed, and the degree of irritation is determined visually based on the color of the skin at the patch site. Test results

[Table] As shown in Table 1, the control patch made of a rubber base had poor moisture permeability and skin irritation. On the other hand, the patches of Experimental Examples 1 and 2 both had high moisture permeability and negative skin irritation, indicating that they were highly safe. The elasticity of each patch in Experimental Example 1 and Control Example using cotton cloth as the packing was high;
This indicates that it is difficult to fit onto the skin. On the other hand, it is clear that the patch of Experimental Example 2, which does not contain cotton cloth, has a low degree of stretch and is easy to fit onto the skin. Example 1 29 parts of Everflex 210, 40 parts of Everflex
Add 13.5 parts of and 12 parts of Nikkor NP-2,
After heating to 130℃ and melting, Ester Gum H
Add 33 parts of and mix well until evenly mixed. After cooling this to 90-100℃ while stirring, add the active ingredient (methyl salicylate) prepared separately.
26.56, dl-menthol 57.08, dl-camphor 4.24,
Add 12.5 parts of thymol 3.2, tocopherol acetate 0.64, peppermint oil 1.04 and ethylene glycol salicylate 7.24 (% by weight) and mix until uniform.
While stirring this, apply 250 ointments on a cotton cloth.
g/m ² to obtain an anti-inflammatory and analgesic patch. Example 2 30 parts of Everflex 210, 40 parts of Everflex
Add 17.5 parts of and 7.5 parts of Nikkor NP-2,
After heating to 130℃ and melting, Ester Gum H
Add 32.5 parts of and mix well until evenly mixed. After cooling this to 90-100℃ while stirring, the active ingredient prepared separately (same as Example 1)
Add 12.5 parts and stir until evenly mixed. This was spread on release paper to a coating amount of 130 g/m ² to form the first layer. Next, add 46 parts of EVAFLEX 210, 28 parts of EVAFLEX 250, and 26 parts of Nikkor NP-2, heat to 135°C to melt, and mix until uniform. Next, cool it while stirring, and after confirming that the temperature is below 110℃, apply it on the first layer while stirring so that the total amount of the paste is 250g/m ² for anti-inflammatory pain relief. A patch was obtained.

Claims (1)

[Claims] 1. 100 parts by weight of an ethylene vinyl acetate copolymer resin having a vinyl acetate content of 15 to 50% by weight and a melt index of 30 to 500 g/10 minutes and HLB3 to 10
polyoxyethylene alkyl phenyl ether
A patch characterized by using a base containing 10 to 50 parts by weight. 2 100 parts by weight of an ethylene vinyl acetate copolymer resin with a vinyl acetate content of 15 to 50% by weight and a melt index of 30 to 500 g/10 minutes and HLB3 to 10
polyoxyethylene alkyl phenyl ether
a first layer using a base containing 10 to 50 parts by weight, and an ethylene vinyl acetate copolymer resin or the ethylene with a vinyl acetate content of 15 to 40 weight % and a melt index of 5 to 500 g/10 minutes; 100 parts by weight of vinyl acetate copolymer resin and 5 to 40 parts of polyoxyethylene alkyl phenyl ether with HLB 3 to 10
A patch comprising a second layer consisting of parts by weight.