Medical diagnostic test strip with desiccant

#This invention relates to medical diagnostic test strips and, more particularly, to a medical diagnostic test strip package having a desiccant disposed in close proximity to the reagents on the test strip such that single strip manufacturing, packaging, shipping, and use is feasible.

#Medical diagnostic test strips are used in a variety of applications. Such strips are exposed to samples of blood, feces, or urine, for example, where specific reagents on the test strip are designed to detect various components in the sample. Medical diagnostic test strips are specifically used to detect the level of glucose in a patient's blood. Such test strips must be exposed to an atmosphere that is substantially moisture-free until moments before use in testing a sample. The strips are often highly water absorbent, and absorption of moisture may alter test results.

#Accordingly, the known industry practice for keeping the test strips dry is to contain a plurality of such test strips in a container or vial. The cap for the container has a desiccant contained in it to absorb water from the air inside the container. In this manner, the strips within the container are kept dry. When ultimately used, a doctor or other testing personnel, including a patient himself, removes the cap from the container, extracts one of the test strips, and immediately places it in the sample to be tested (or places a small quantity of the sample to be tested on the test strip) Exposure of the strips to the ambient atmosphere before use is thus minimized to reduce water vapor absorption by the test strip.

#FIG. 1 is a perspective view of a first exemplary embodiment of the present invention;

#FIG. 2 is a perspective view of a second exemplary embodiment of the present invention;

#FIG. 3 is a partially cut-away perspective view of a third exemplary embodiment of the present invention;

#According to the present invention, individual medical diagnostic test strips are packaged in a moisture-free environment by disposing a desiccant in close proximity to the reagents used on the test strip. FIG. 1 shows a first exemplary embodiment of the present invention. In FIG. 1, test strip 10 is shown having reagent pad 11 attached to it. Reagent pad 11 contains the particular compounds necessary to perform the desired detection test for a sample in a particular application. In some cases, depending on the particular reagents used, reagent pad 11 changes color upon exposure to the test sample. This color change can be observed and possibly measured to yield information regarding the presence or amount of the component being measured. In other cases, other measurable or observable characteristics of reagent pad 11, such as reflectance, may change upon exposure to the test sample and thereby yield the desired information regarding the sample.

#Exemplary test strips and reagent pads used to measure the amount of glucose in the blood, and the manufacture and use of such test strips and reagent pads, are described in U.S. Pat. Nos. 4,935,346; 5,049,487; and 5,304,468, all of which are hereby incorporated by specific reference for their teachings on the manufacture and use of test strips and reagent pads.

#Alternatively, reagent pad 11 may have the structure shown in FIG. 6. In FIG. 6, upper liner 60 is typically formed of polyethylene terephthalate (or PET) and has a conventional cold or hot melt adhesive on its bottom surface 64. A reagent paper layer 61, having the required reagents for a particular application on it, is adhered to bottom surface 64 of upper liner 60. A double-sided tape layer 62 is used to adhere reagent paper layer 61 to lower liner 63, which is typically formed of PET. After assembly of the composite layers shown in FIG. 6, reagent pad 11 is adhered to test strip 10 by conventional cold or hot melt adhesives placed around the edges of upper surface 65 of upper liner 60. Test strip 10 has a hole 19 formed in it to access reagent pad 11.