WO2017062522A1

WO2017062522A1 - Lateral flow device for detecting xerostomia

Info

Publication number: WO2017062522A1
Application number: PCT/US2016/055596
Authority: WO
Inventors: Jerry B. Gin; Benjamin F. Ross
Original assignee: Bennes Inc.
Priority date: 2015-10-05
Filing date: 2016-10-05
Publication date: 2017-04-13

Abstract

A dry mouth test is provided comprising placing a wickable test strip in the mouth of a subject to collect salivary fluid. Distance migrated by the saliva over a specific period of time correlates with the production of saliva and dryness of the mouth. A marker dye is optionally used on the strip which co-migrates with the saliva front and aids in indicating the distance saliva migrates on the strip. A graduated migration scale is printed on the strip to indicate the distance traveled by the saliva. Saliva production is measured with or without stimulation of the salivary glands.

Description

LATERAL FLOW DEVICE FOR DETECTING XEROSTOMIA

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application Serial No. 62/237,330 filed October 5, 2015 and entitled LATERAL FLOW DEVICE FOR

DETECTING XEROSTOMIA, the contents of which are incorporated herein in their entirety by reference.

TECHNICAL FIELD OF THE INVENTION

[0002] The present invention relates to diagnostics for xerostomia or dry mouth condition. Specifically, the invention relates to lateral flow devices, such as test strips, which can detect presence of a dry mouth condition.

BACKGROUND OF THE INVENTION

[0003] Xerostomia is dry mouth caused by reduced or absent flow of saliva. This condition can result in discomfort, interfere with speech and swallowing, make wearing dentures difficult, cause halitosis (Halitosis), and impair oral hygiene by causing a decrease in oral pH and an increase in bacterial growth. Long-standing xerostomia can result in severe tooth decay (Caries) and oral candidiasis (chronic mucocutaneous candidiasis (CMC)). Xerostomia is a common complaint among older adults, affecting about 20% of the elderly.

[0004] Dry mouth is a growing problem. As a person ages, the number of medications taken by the person increases. About 1,800 medications are known to cause dry mouth. 75% of prescription drugs and many over-the-counter (OTC) drugs have dry mouth as a side effect. The most common include the following: anti-cholinergics, anti-Parkinsonian drugs, antineoplastics (chemotherapy), anti-hypertensives, anxiolytics, and antidepressants. As a result, about 70 million persons suffer from dry mouth and 1 out of 3 persons over the age of 45 have dry mouth.

[0005] Several systemic disorders such as Sjogren's syndrome, diabetes mellitus, rheumatoid arthritis, and systemic lupus erythematosus are also known to cause oral dryness. Other causes include head and neck injuries which damage nerves to the salivary glands. Head and neck cancers in which radiation and chemotherapy are used is another cause of dry mouth. Tobacco use usually causes a decrease of saliva. The rise of illicit methamphetamine use has resulted in an increasing incidence of meth mouth, which is severe tooth decay caused by methamphetamine-induced xerostomia. The damage is exacerbated by the bruxing and clenching caused by the drug and by the heat of the inhaled vapor. This combination causes very rapid destruction of teeth.

[0006] With regard to an increasingly elderly population and its dependent use of medication, a multitude of negative side effects associated with disturbed salivary function will present a medico-socio-economic problem not only for the individual per se but also for society in the near future.

[0007] Problems with dry mouth include difficulty in swallowing and eating, difficulty in speaking because of dry vocal cords, feeling of thirst, soreness of the throat and mouth, cracked lips, parched tongue and parched mouth. In addition to these physical problems, dry mouth results in oral health problems such as increased risk for cavities, gingivitis (inflamed gums), periodontitis (inflammation of gums leading to loss of teeth), mouth sores, fungal infections of the mouth, and bad breath. It is thus important to know the degree of dryness of the mouth so that precautions can be taken to prevent the oral health problems.

[0008] The cause of xerostomia is often apparent, but if the etiology is unclear and systemic disease is considered possible, further assessment should be pursued with biopsy of a minor salivary gland (for detection of Sjogren syndrome, sarcoidosis, amyloidosis, TB, or cancer) and HIV testing. The lower lip is a convenient site for biopsy. Further information about xerostomia is available at www(dot)merckmanuals(dot)com/professional/dental- disorders/symptoms-of-dental-and-oral-disorders/xerostomia (accessed August 27, 2015).

[0009] Current dry mouth tests are not simple and typically involve measuring the amount of saliva produced over a defined time. This involves spitting into a container or tube hooked up to a container. The most advocated clinical method for diagnosing salivary gland dysfunction is to quantitate unstimulated and stimulated whole saliva flow rates (sialometry). The cut-off value for a very low unstimulated and stimulated whole saliva flow rate is claimed to be < 0.1 ml/min and < 0.7 ml/min, respectively which is generally referred in the literature to studies by Ericsson and Hardwick (Ericsson Y, Hardwick L: Individual diagnosis, prognosis and counseling for caries prevention. Caries Res. 1978, 12: 94-102. 10.) and Sreebny and Valdini (Sreebny LM, Valdini A: Xerostomia: Part I: Relationship to other oral symptoms and salivary gland hypofunction. Oral Surg Oral Med Oral Pathol. 1988, 66: 451-458). Existing methods to diagnose oral dryness and salivary gland function are reviewed by Lofgren et al. BMC Oral Health 2012, 12:29.

[0010] There is a need for novel rapid and sensitive methods and apparatus for detecting and classifying xerostomia or dry mouth condition.

SUMMARY OF THE INVENTION

[0011] The objective of the present invention is to alleviate at least one of the problems set forth in the background section. The objective is achieved by implementing an assay based on a lateral flow device for detection of dry mouth condition. Optionally, a colorimetric detection scheme may be added.

[0012] In some embodiments the lateral flow device is a test strip composed of wickable and wettable material.

[0013] The novel test for dry mouth disclosed herein uses a test strip placed within the mouth and then measuring the length of migration of saliva on the strip to give a quantitative value for the degree of dryness of the mouth/amount of saliva produced.

[0014] In preferred embodiments, a test strip capable of wetting and wicking is placed in the mouth with the tip of the strip placed at the bottom of the mouth below the tongue of a subject, after the subject gets rid of residual saliva before inserting the strip. In other embodiments, a test strip capable of wetting and wicking is placed in the mouth with the tip of the strip placed at the bottom of the cavity formed by the juncture between the lower lip and inner gums. Saliva, which accumulates at this juncture, will wick through the strip and the distance in which it migrates within a set period of time is an indication of the amount of saliva produced and thus it is a measure of the degree of dryness of the mouth.

[0015] In some embodiments, a dye which co-migrates with the saliva front is optionally incorporated to indicate the distance moved by the saliva as it wicks for a defined length of time.

[0016] In some embodiments, a scale is printed on the strip to aid in reading the distance moved by the dye.

[0017] In another aspect the present invention provides kits for analyzing a liquid sample. The kits include a device of the present invention in a package with instructions for use. In different embodiments the kit can also include an assay result comparison chart or other standard. The kit can be packaged in any convenient format, for example, in a box or in a plastic wrapping, or in a foil pouch, which can be vacuum-sealed.

[0018] The present invention includes a variety of other useful aspects, which are detailed herein. These aspects of the invention can be achieved by using the articles of manufacture and compositions of matter described herein. To gain a full appreciation of the scope of the present invention, it will be further recognized that various aspects of the present invention can be combined to make desirable embodiments of the invention. In addition, a variety of other aspects and embodiments of the present invention are described herein.

[0019] The summary of the invention described above is not limiting and other features and advantages of the invention will be apparent from the following detailed description, as well as from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present disclosure, the inventions of which can be better understood by reference to one or more of these drawings in combination with the detailed description of specific embodiments presented herein.

[0021] FIG. 1 A shows a dry mouth test strip of the present invention.

[0022] FIG. IB shows a typical example of a lateral flow test strip prepared according to the present invention. An optional blue wicking indicator is included in this diagram.

[0023] FIG. 2A-2C show the performance of a dry mouth test according to this invention. Fig. 2A shows holding of the strip so that the strip can be inserted into the bottom of the space beneath the tongue. Fig. 2B shows insertion of the test strip in the sublingual space after draining saliva from the mouth. Fig. 2C shows tilting of the head slightly downward by bringing the chin toward the neck to allow saliva to pool in the bottom of the mouth.

[0024] Figure 3 shows correlation of the results from Xerocheck® Dry Mouth Test and sialometry on subjects with and without dry mouth condition.

DETAILED DESCRIPTION OF THE INVENTION

[0025] The terms used in this specification generally have their ordinary meanings in the art, within the context of the invention, and in the specific context where such term is used. Certain terms that are used to describe the invention are discussed below, or elsewhere in the specification, to provide additional guidance to the practitioner regarding the description of the invention. For convenience, certain terms may be highlighted, for example using italics and/or quotation marks. The use of highlighting has no influence on the scope and meaning of a term; the scope and meaning of a term is the same, in the same context, whether or not it is highlighted. It will be appreciated that same thing can be said in more than one way.

Consequently, alternative language and synonyms may be used for any one or more of the terms discussed herein, nor is any special significance to be placed upon whether or not a term is elaborated or discussed herein. Synonyms for certain terms are provided. A recital of one or more synonyms does not exclude the use of other synonyms. The use of examples anywhere in this specification including examples of any terms discussed herein is illustrative only, and in no way limits the scope and meaning of the invention or of any exemplified term. Likewise, the invention is not limited to various embodiments given in this

specification.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the case of conflict, the present document, including definitions will control.

[0027] The presence and severity of xerostomia can be assessed in several ways. For example, a tongue blade can be held against the buccal mucosa for 10 sec. If the tongue blade falls off immediately when released, salivary flow is considered normal. The more difficulty encountered removing the tongue blade, the more severe the xerostomia. In women, the lipstick sign, where lipstick adheres to the front teeth, may be a useful indicator of xerostomia.

[0028] If there appears to be dryness, the submandibular, sublingual, and parotid glands should be palpated while observing the ductal openings for saliva flow. The openings are at the base of the tongue anteriorly for the submandibular and sublingual glands and on the middle of the inside of the cheek for the parotid glands. Drying the duct openings with a gauze square before palpation aids observation. If a graduated container is available, the patient can expectorate once to empty the mouth and then expectorate all saliva into the container. Normal production is 0.3 to 0.4 mL/min. Significant xerostomia is 0.1 mL/min.

[0029] For patients in whom the presence of xerostomia is unclear, sialometry can be conducted by placing collection devices over the major duct orifices and then stimulating salivary production with citric acid or by chewing paraffin. Normal parotid flow is 0.4 to 1.5 mL/min/gland. Flow monitoring can also help determine response to therapy.

Lateral Flow Test Strips

[0030] In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. It is understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention.

[0031] FIG. 1 shows one embodiment of the present invention, a lateral flow test strip 100 of the present invention. The test strip comprises a bibulous material 110. The bibulous material 110 can be made of any material that supports capillary flow, such as but not limited to polyamide fiber, polyester, filter paper, nitrocellulose, hydrophilic meshes, glass meshes treated to become hydrophilic, and the like. The bibulous material 110 is a wicking material that can freely wick liquid sample (in a direction shown as large arrow 170) from one end of the strip to the other end within a period of time necessary to conduct a valid assay. This will usually be a matter of minutes.

[0032] The test strip 100 comprises a proximal end 120 for insertion into an oral cavity for contact with an oral fluid and a distal end 130 towards which the oral fluid migrates by a wicking action along the body of the strip in a direction shown by large arrow 170. In some embodiments, the test strip further comprises a wickable chromophore 140 pre-applied at a specific distance from the proximal end. The wickable chromophore 140 co-migrates with the saliva front towards the distal end 130 and the length of migration indicates the amount of saliva present in the oral cavity of the subject. Preferably the chromophore 140 is a single component food dye. In order to more precisely measure the distance migrated by the saliva front a scale 150 is printed on the test strip in some embodiments.

[0033] In some embodiments of the test strip, the specific distance is about 10, 15, 20, 25, 30 or 40 mm from the proximal end.

[0034] In some embodiments of the test strip, the chromophore is a commercial food dye.

[0035] The test strip is preferably made of made of 3MM filter paper (Whatman^® #41), but other types of filter paper and other materials can also be used. Many different bibulous materials will find use in the present invention. Any material that has a liquid wicking quality and efficiently transports liquid can be used as the bibulous material. In some embodiments the test strips of the invention comprise a single strip of bibulous material. The bibulous material is normally in the shape of a rectangle or strip, but can also be provided in any other shape that does not distort the results of the assay.

[0036] In one embodiment the bibulous material is a polyamide fiber. Membrane thicknesses of between 0.6 and 1.0 mm are useful. The bibulous material is absorptive in its nature, and in this embodiment a fiber material of 60 mm x 10 mm will absorb 0.6 g of fluid, +/-0.15 gm. Polyamide fibers are available as wicking material from Filtrona Fibertec^® (Colonial Heights, Va.). Of course other bibulous materials also find use in the invention. For example, surface active media that are often used as filtering materials and utilize either amine or carboxyl groups on the surface of the fiber as substrates for a wide variety of linking agents can also be used. This material also functions well in the present invention as bibulous material when supplied as a sheet or strip, and is available from Filtrona Fibertec^® (Colonial Heights, Va.). Other embodiments include, but are not limited to, the use of cotton fiber.

[0037] The bibulous materials used in the invention have a contact point or region 180 for the liquid sample, which is the point where the test strip is introduced into or exposed to the sample and the point where a liquid sample enters the bibulous material. In one embodiment the test strips of the invention have a single contact point or region 180.

[0038] One specific embodiment of the invention is use of a suitable material which must be able to absorb saliva and wick the saliva by capillary action. An ashless, non-hardened analytical filter paper with flow characteristics similar to Whatman^® #41 filter paper is a suitable material. (Fig. IB). The shape of the test strip/filter paper can be rounded or rectangular. A filter paper with the dimensions of 0.25 inches (6.35 mm) by 100 mm or 12mm by 90 mm (Fig. IB) is a suitable size.

[0039] A marking dye may be used on the strip to facilitate the visualization of the saliva migration front. The dye may be applied to the strip in a variety of ways during

manufacturing (e.g., by printing). It is not critical to the function of the test. FD&C Blue. FD&C Red #40, FD&C Green #3, FD&C Yellow #6, FD&C Lakes and other commercial food dyes can be used.

[0040] To facilitate reading the migration distance, a scale (in millimeters or inches) can be printed on the strip. Alternately, the distance saliva or oral fluid migrated on the test strip can be measured manually using a marker and/or a measuring device.

[0041] Kits comprising each strip packaged individually in a pouch are also provided. [0042] In methods according to the invention, the sample end of a test strip is placed at the bottom of the mouth below the tongue of a subject after the subject has been rid of the residual saliva at this sublingual space. A timer is initiated as soon as the strip is placed in the mouth. The distance which saliva wicks at (exactly) 1, 2, 3, 4, 5, 7, 10 or 15 minutes is measured in millimeters or inches.

[0043] A food color dye is optionally pre-applied on the test strip at about 5, 10, 15, 20, 25, 30 or 40 mm from the sample end which wicks with the saliva when the saliva wicks beyond the site of application of the dye. This helps identify how far the wicking occurred in a specific period of time since application.

[0044] At exactly the end of the period of time wicking is to be measured, the strip is removed from the mouth and iterated to remove excess saliva and stop the wicking. The filter paper is marked at the length the saliva has wicked at exactly the end of the specified period. If the wicking has gone beyond the site of the pre-applied dye, the migration front will be indicated by where the dye front ends on the strip. The distance wicked from the wet end of the test strip (the part of the strip that was in the mouth) to the point marked by the pencil or blue front (blue wicking indicator line shown in Fig. IB) at the end of the specified period of time is noted. This provides a measure of the level of saliva flow.

[0045] Saliva flow may be measured under both unstimulated and stimulated conditions. Stimulation of the salivary glands may be carried out by any means including by chewing gum. A person with dry mouth will not produce appreciably more saliva upon stimulation. For the stimulated flow of saliva, a piece of gum is chewed for a specific amount of time and then the gum is discarded. The period gum is chewed can be 1, 2, 3, 4, 5 or 10 minutes.

However, the time period must be followed precisely.

[0046] Using test strips comprising Whatman^® #41 filter paper: for persons with a normal flow of unstimulated saliva, the length of wicking was in the range of 15 to 65 mm. Upon stimulation, for persons with normal flow of saliva, the length of wicking is 25 to 70 mm.

[0047] For persons with chronic dry mouth, for unstimulated flow of saliva, the length of wicking is less than about 15 mm. For persons with chronic dry mouth, for stimulated flow of saliva, the length of wicking is generally less than 25 mm. EXAMPLES

[0048] Without intent to limit the scope of the invention, exemplary instruments, apparatus, methods and their related results according to the embodiments of the present invention are given below. Note that titles or subtitles may be used in the examples for convenience of a reader, which in no way should limit the scope of the invention. Moreover, certain theories are proposed and disclosed herein; however, in no way they, whether they are right or wrong, should limit the scope of the invention so long as the invention is practiced according to the invention without regard for any particular theory or scheme of action.

Example 2: Unstimulated Dry Mouth Test

[0049] A representative Dry Mouth Test according to the instant invention is described as follows: The Dry Mouth Test is used to determine the amount of saliva in the mouth. The Dry Mouth Test is designed to measure the amount of saliva under the tongue by measuring the migration distance of the saliva on a filter paper test strip in 2 minutes. Before performing the test the expected level of dryness in mouth may be noted as: "Normal" (no dry mouth), "Mild," Moderate." or "Severe."

[0050] Xerocheck™ Dry Mouth Test Strips of 70 millimeter length were used in the test. The strip is laminated from 1-2 mm below wi eking tip of strip to about the 50 mm marker or longer. The lamination avoids wetting of the strip from the lips and areas of the strip other than the tip which can come in contact with the mouth. The part of the strip that is laminated and has blue coloration is considered the top of the strip and is the portion that will be inserted into the mouth. The top of the strip is considered "0" millimeter.

[0051] The test strip about 100 mm in length is placed under the tongue at the floor of the mouth behind lower front teeth. The proximal end 120 of the strip that is inserted into the mouth is considered "0" millimeter. The strip is held so that the strip can be inserted into the bottom of the space beneath the tongue (Figure 2A). One can use a mirror or have someone insert it in the mouth.

[0052] As much as possible of the saliva in your mouth and below the tongue is swallowed so the mouth is as dry as possible. To further drain saliva from the mouth, the head is tilted back so you are looking up toward the ceiling. At 20 seconds, swallow again. At 30 seconds, bring your head back to normal position (looking ahead) and proceed immediately to the next step of inserting the test strip into the mouth. [0053] Once inserted, use the tongue to hold the strip in place at the bottom of the space under the tongue just behind the teeth throughout the 2 minutes wi eking period.

[0054] Close the mouth and start the timer. Timing starts as soon as the strip is placed in the mouth (Figure 2B). The head is tilted slightly downward by bringing the chin toward the neck to allow saliva to pool in the bottom of the mouth. (Figure 2C).

[0055] At exactly 2 minutes, remove the strip from the mouth and immediately mark the strip with a pencil at the length the saliva has wicked at exactly 2 minutes. The blue coloration will have wicked with the saliva, indicating the distance wicked. However, the wicking will continue even after the strip has been removed from the mouth, so a pencil line is needed to indicate the true distance wicked at 2 minutes. The distance which saliva wicks at exactly 2 minutes is measured in millimeters.

[0056] A blue food color dye such as FD&C Blue, may optionally be placed at 20 mm on the strip which co-migrates with the saliva front if the saliva wicks beyond 20 mm. This also helps identify how far the wicking occurred. Where the blue wicking indicator is not included in the strip, look at the strip in front of a light to see the wicking distance of the saliva and mark that distance with a pencil.

[0057] At exactly 2 minutes, the strip is removed from the mouth and immediately blotted with tissue in order to remove excess saliva and stop the wicking. The filter paper is marked with a pencil at the length the saliva has wicked at exactly 2 minutes. The millimeter scale is printed on the strip. If the wicking has gone beyond 20 mm, the migration front will be indicated by where the blue front ends on the strip. The distance wicked from the wet end of the test strip (the part of the strip that was in the mouth) to the point marked by the pencil or blue front at 2 minutes is marked. The distance wicked by the saliva front from the proximal end of the wet paper strip (the part of the strip that was in the mouth) to the point is marked by a pencil or the blue dye front after 2 minutes. An optional scale printed on the worksheet may be used to aid the measurement. This provides the result of the unstimulated level of saliva flow.

Example 3 : Stimulated Dry Mouth Test

[0058] Stimulation of the salivary glands is carried out by chewing gum or paraffin. A person with dry mouth will not produce appreciably more saliva upon stimulation. For the stimulated flow of saliva, a piece of gum is chewed for exactly 1 minute and then discarded. The test is then repeated by placing the test strip between the lips and gums in a manner similar to that described above (Figures 2C and 2D), the timer is started and wicking is measured after exactly 2 minutes (or a specific period of time). The distance wicked by the saliva front from the proximal end of the wet paper strip (the part of the strip that was in the mouth) to the point is marked by a pencil or the blue dye front after 2 minutes (or the specific period of time). An optional scale printed on the worksheet may be used to aid the measurement. The distance wicked in millimeters indicates the stimulated level of saliva flow.

Example 4: Results observed with the Dry Mouth Test

[0059] Tests were carried out using test strips composed of Whatman #41 filter paper:

[0060] For persons with a normal flow of unstimulated saliva, the length of wicking was in the range of 20 to 65 mm.

[0061] Upon stimulation, for persons with normal flow of saliva, the length of wicking was 25 to 70 mm.

[0062] For persons with chronic dry mouth, for unstimulated flow of saliva, the length of wicking was less than 15 mm.

[0063] For persons with chronic dry mouth, for stimulated flow of saliva, the length of wicking was less than 25 mm.

Example 5: Correlation of Dry Mouth Test Versus Unstimulated Sialometry

[0064] The Xerocheck Dry Mouth Test was carried out with 11 persons, 5 of whom reported they had dry mouth according to a Questionnaire on dryness. Of the 5 subjects, one had Sjogren's Syndrome, one had throat radiation from cancer treatment which caused the dry mouth condition, one takes sleep medication and reported a level 8 of 10 on dryness of the mouth, one reported difficulty swallowing food which was not wet, and one reported moderate dryness on the questionnaire, with no other dryness indications.

[0065] Sialometry is the assessment of the secretory capacity of a patient, measuring the total secretions accumulating in the mouth (oral fluid) over a specific period of time and reflects the overall capacity of all salivary glands. (Veerman EC, Keijbus van den PAM, Vissink A, Nieuw Amerongen AV. Human glandular salivas: their separate collection and analysis. Eur J Oral Sci 1996; 104:346-352.) [0066] Results from Sialometry (grams saliva accumulated after 5 minutes) versus Dry Mouth Test according to the invention (millimeters wicked at 2 minutes) are shown in Figure 3.

[0067] The data from which Figure 3 was obtained is presented in Table 1 highlighting a cluster where the Dry Mouth Test correlated with Sialometric measurements.

[0068] A cluster of subjects displayed both low unstimulated Sialometry (0.5 ml or less of saliva at 5 minutes) as well as low Xerocheck results (less than 15 mm migration distance). This cluster of patients all had dry mouth clinical symptoms.

[0069] For subjects with no complaints of dry mouth, all subjects had higher levels of wicking in the Dry Mouth Test (results showed greater than 30 mm migration distance). For persons with no clinical signs of dry mouth, the Dry Mouth Test showed results greater than 30 mm and for those with dry mouth showed results less than 20 mm.

[0070] In patients with dryness of the mouth, Sialometry correlates with the Dry Mouth Test migration results. For the dentist, a Dry Mouth Test result will help confirm a dry mouth condition and would be an adjunct to clinical observations such as obtained by the

Challacombe Clinical Oral Dryness Scale (CODS; British Dental Journal 111, 351 (2011)).

[0071] All publications and patent applications cited in this specification are herein incorporated by reference as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference.

[0072] Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be readily apparent to those of ordinary skill in the art in light of the teachings of this invention that certain changes and modifications may be made thereto without departing from the spirit or scope of the appended claim.

Claims

CLAIMS What is claimed is:

1. A test strip device for measuring dry mouth condition, the device comprising:

a bibulous material for transporting liquid sample through the test strip, wherein the bibulous material comprises: a proximal end for insertion into an oral cavity for contact with an oral fluid and a distal end towards which the oral fluid migrates by a wicking action along the body of the strip.

2. The device of claim 1 wherein the bibulous material is comprised of polyamide fiber.

3. The device of claim 1 wherein the bibulous material is comprised of 3MM filter paper.

4. The device of claim 1 wherein the oral fluid is saliva.

5. The device of claim 1, further comprising a wickable chromophore pre-applied at a specific distance from the proximal end.

6. The device of claim 5, wherein the specific distance is about 5, 10, 15, 20, 25, 30 or 40 mm from the proximal end.

7. The device of claim 5, wherein the chromophore is a single-component food dye.

8. The device of claim 7, wherein the commercial food dye is selected from FD&C Blue, FD&C Red #40, FD&C Green #3, FD&C Yellow #6, and FD&C Lakes.

9. The device of claim 1 wherein the test strip has a rectangular or a rounded shape.

10. The device of claim 1, further comprising a scale printed on a surface of the test strip.

11. The device of claim 10, wherein the scale is in millimeters or inches.

12. The device of claim 1, wherein the test strip is laminated from 1-2 mm from the proximal end to about 50 mm or more towards the distal end.

13. A method for detecting a dry mouth condition in a subject, the method comprising the steps of: a) providing a test strip device comprising: a bibulous material for transporting liquid sample through the test strip, wherein the bibulous material comprises: a proximal end for insertion into an oral cavity of the subject suspected of having a dry mouth condition at a location suitable for contact with a salivary fluid and a distal end towards which the oral fluid migrates by a wicking action along the body of the strip;

b) inserting the proximal end into a space within the mouth of the subject where salivary fluid accumulates;

c) measuring the distance migrated by the salivary fluid along the body of the strip towards the distal end caused by wicking action, over a specific period of time; and

d) comparing the migration distance to that of a normal subject with no dry mouth condition, wherein a lower migration distance compared to the normal migration distance is indicative of a dry mouth condition.

14. The method of claim 13, wherein the specific period of time is selected from 1, 2, 3, 4, 5, 7, 10 and 15 minutes.

15. The method of claim 13, wherein the distance travelled is measured manually.

16. The method of claim 13, wherein the distance travelled is measured by pre-applying a wickable chromophore at a specific distance from the proximal end and measuring the distance co-migrated by the chromophore with the salivary fluid.

17. The method of claim 16, wherein the specific distance is about 5, 10, 15, 20, 25, 30 or 40 mm from the proximal end.

18. The method of claim 16, wherein the chromophore is a commercial food dye.

19. The method of claim 18, wherein the commercial food dye is selected from FD&C Blue, FD&C Red #40, FD&C Green #3, FD&C Yellow #6, and FD&C Lakes.

20. The method of claim 13, wherein the location within the oral cavity of the subject is a sub-lingual space.

21. The method of claim 13, wherein the method is carried out in a subject unstimulated for salivary flow.

22. The method of claim 21, wherein the migration distance is less than 15 mm under stimulated conditions.

23. The method of claim 21, wherein the dry mouth condition is further confirmed by unstimulated sialometry.

24. The method of claim 13, wherein the method is carried out in a subject stimulated for salivary flow.

25. The method of claim 13, wherein the subject is stimulated for salivary flow by chewing gum for a specific period of time immediately prior to the test.

26. The method of claim 25 wherein the subject chews gum for exactly 1, 2, 3, 4, 5 or 10 minutes.

27. The method of claim 13 wherein the normal salivary fluid production of 0.3 to 0.4 mL/min corresponds to a migration distance of 15 to 65 mm over 5 minutes in an

unstimulated condition when measured on a test strip comprising Whatman#41 paper.

28. The method of claim 27, wherein the migration distance is 25 to 70 mm under stimulated conditions.

29. The method of claim 13 wherein a subject with chronic dry mouth displays a migration distance of less than 15 mm over 2 minutes in an unstimulated condition when measured on a test strip comprising Whatman#41 paper.

30. The method of claim 29, wherein the migration distance is less than 25 mm under stimulated conditions.

31. A kit comprising the device according to any of claims 1-12.