JPS609221Y2 - patch - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a patch in which a drug is retained in an adhesive layer formed on a base material.

Generally, in this type of patch, the drug and an adhesive polymer are mixed together to form the drug-containing adhesive layer, so the drug tends to be difficult to diffuse efficiently from the surface of the adhesive layer. .

For this reason, a release auxiliary substance that promotes the release of the above drug,
Attempts have been made to include so-called adjuvants in the adhesive layer, but even this may not be as effective as expected.

This idea was made in view of the above circumstances, and instead of relying on a method of mixing drugs and adhesive polymers together, it is possible to apply drugs to a layer consisting only of an adhesive composition formed on a base material. By forming a drug-based storage layer in which the composition containing the drug is embedded and exposed on the surface of the adhesive layer,
An object of the present invention is to provide a patch that can effectively release a drug from the surface of an adhesive layer.

An embodiment of this invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a base material, which is made of a fiber sheet, a synthetic resin film, or a hybrid thereof.

Here, fiber sheets include nonwoven fabric, cloth, paper, etc.
Examples of synthetic resin films include polyethylene, polyvinyl chloride, polyurethane films, polyacrylic films, and ethylene-vinyl acetate copolymer films.

2 is an adhesive layer made of an adhesive composition formed on the main surface of the base material 1; 3 is a drug-based drug storage layer scattered in the adhesive layer 2; The layer 3 is embedded in the pressure-sensitive adhesive layer 2 so as to be exposed on the surface thereof.

As a drug, it can be widely applied as long as it can be transferred or adsorbed to the body surface, such as antibiotics such as penicillin, anesthetics such as lidocaine,
These include pain-relieving anti-inflammatory drugs such as salicylamide and sodium salicylate.

The patch having the above structure is produced by heating and melting an adhesive composition made by blending various adhesive polymers with tackifiers and other known additives as necessary, and applying the adhesive composition to the main surface of the base material 1. Then, before the applied adhesive composition has cooled down completely, a drug-containing composition, such as a polymer or other substance that is solid at room temperature, is injected with the drug using an injection device with multiple injection needles. A release auxiliary substance, a so-called adjuvant, is mixed into the adhesive composition in the same manner as above, heated and melted, and then injected sporadically into the pressure-sensitive adhesive composition.Then, the composition is then naturally cooled and solidified. can be manufactured.

Substances that are solid at room temperature and used in drug-containing compositions include various polymers such as polyvinyl alcohol, waxes, and greases, but these solid substances tend to dissipate drugs, that is, they tend to dissolve drugs. Moreover, those which are hardly compatible with the polymer component of the adhesive layer 2 are selected and used.

In this way, in the above structure, the drug is not directly mixed into the adhesive layer 2, but the drug storage layer 3 mainly composed of the drug is provided partially in the adhesive layer 2, so that the drug content density can be reduced. Since a high portion of the drug exists locally in the adhesive layer 2, and each drug storage layer 3 is exposed on the surface of the adhesive layer 2 and acts as a bypass path during drug release, it is compared to the conventional method. However, drug release properties are significantly improved.

On the other hand, in the above configuration, if there is a risk that the drug will be released in a short period of time due to the drug storage layer 3 mainly consisting of the drug,
A diffusion suppressing agent layer that suppresses diffusion of the drug may be provided on the surface side of the drug storage layer 3 as one of the constituent elements of the storage layer 3.

This diffusion-inhibiting agent layer may be made of a material that is less likely to dissolve the drug than the polymer or other solid substance used in the drug-containing composition.

By the way, as the polymer or other solid substance used in the drug storage layer 3 mainly containing the drug, that is, the composition containing the drug, a polymer or other solid substance that is hardly compatible with the polymer in the adhesive layer 2 is selected as described above. However, there is still a considerable possibility that the drug or adjuvant in the drug storage layer 3 may migrate from the boundary with the adhesive layer 2 to the adhesive layer 2 side.

Due to such migration, not only the purpose of providing the drug storage layer 3 is lost, but also the adhesive layer may be plasticized and its strength may be reduced.

In order to prevent this, the adhesive layer 2 is cross-linked using ultraviolet rays or the like, or, as shown in FIG. 2, a barrier wall 4 is formed at the boundary with a substance that is difficult for drugs or adjuvants to pass through, such as trans-isoprene. By doing so, the above-mentioned migration problem can be solved, and compatibility between polymers can also be prevented.

When the partition wall 4 is provided, as shown in FIG.
This can be easily formed by using a double-barreled injection needle M that accommodates the .

Of course, even in this case, the above-mentioned release inhibitor layer can be formed on the surface side of the drug storage layer 3 if necessary.

As described above, this invention improves drug dispersion by forming a drug-based storage layer exposed on the surface of the adhesive layer in the adhesive layer formed on the base material. A patch that can maintain its medicinal efficacy over a long period of time can be provided.

[Brief explanation of drawings]

Fig. 1 is a partially enlarged sectional view showing an example of the patch according to this invention, Fig. 2 is a partially enlarged sectional view showing a modification of the patch, and Fig. 3 is an explanatory diagram of a double barrel injection needle. It is. 1...Base, 2...Adhesive layer, 3...
...Drug storage layer.

Claims (1)

[Scope of utility model registration request] Only the adhesive composition is formed in a layer on the main surface of the base material, and a composition containing a drug is scattered in this adhesive layer to form a drug-based drug storage layer. A patch in which a layer is exposed on the surface of the adhesive layer.