| 摘要 |
An adhesive patch for skin testing using chemical substances such as dinitrochlorobenzene (DNCB), oxazolone, beryllium fluoride, paraphenylenediamine or other like allergens, the allergen being mixed with an excipient which melts when placed in contact with the skin. The adhesive patch provides a sandwich-type construction that includes an adhesive layer, a first foil layer with one side against the adhesive layer, a layer of liquid impermeable synthetic mterial on the other side of the foil face, an absorbent disc on the synthetic layer, the allergenic material on the absorbent disc and a second foil layer overlying the absorbent disc and forming an air-tight seal with the first foil layer. In use the second foil layer will be removed and the patch adhesively applied to the skin of a user without fear of sensitization of the person handling the patch test. The patch test is formed by a continuous process wherein a first web of foil that has been covered with a web of synthetic material is advanced longitudinally, separate discs of absorbent material being placed on the synthetic material side of the web at regular intervals as the web is transported longitudinally; the test material diluted in solvent is deposited onto each absorbent disc as same passes a dispensing station, the solvent is evaporated before sealing, and a second web of foil is fed to overlie the first foil web and is then heat-sealed thereto to form discrete pouches in each of which is located an absorbent disc, the sandwiched webs are severed to provide individual units that are then deposited on a web of adhesive patch material in spaced relation, a web of protective material is applied to the adhesive patch material with the spaced units located between said latter two webs, and the further sandwich is severed to produce completed individual units.
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