A patch and patch preparation comprising a support and adhesive layer

The present invention addresses the problem of providing: a patch that does not exhibit blooming even when a hydrophobic adhesive layer therein contains a highly polar organic fluid component, and that is provided with an adhesive layer having high adhesion strength; and a patch preparation. A patch in which an adhesive layer is provided on at least one surface of a supporting body, wherein the adhesive layer includes a synthetic rubber having a viscosity average molecular weight of 1,700,000-6,500,000, a highly polar organic fluid component, a tackifier, and magnesium aluminometasilicate. In addition, in the patch preparation the adhesive layer also contains a drug.