JPH0815260A - Time indicator - Google Patents

Abstract

PURPOSE:To display the lapse of time and the finishing time of an external diagnostic medicine for chromatographic development OTC by applying a composition containing a color reagent, a binder, a water absorptive powder, and a pH buffer to the same supporting body for the external diagnostic medicine or doping the supporting body with the composition. CONSTITUTION:Sodium fluoracene and Tetrabromophenol Blue are preferably used for so-called a wet detecting agent which changes color by being brought into contact with a liquid and for a substance which detects the component existing constantly in a body fluid and changes the color tone, respectively. As a binder, one which does not affect the pH of the body fluid and does not interfere the reagent reaction is preferable. As a water absorptive powder, one which does not affect the reagent composition at the time when it is brought into contact with water and has highly white color, spherical shape, and uniform particle size is preferable. A pH buffer is used to keep pH at which the color reagent causes desirable color change in the composition. A composition containing 0.05-5% of the color reagent, 0.5-10% of the binder, 20-70% of the water absorptive powder, and 0-20% of the pH buffer by weight is used to coat or dope the same supporting body for a detecting reagent with it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a time indicator used as an in-vitro diagnostic agent using body fluid such as urine or blood.

[0002]

2. Description of the Related Art In recent years, in-vitro diagnostic agents for OTC have been developed with the increasing awareness of self-care among ordinary people.
In-vitro diagnostics for OTC are required to be able to make a simple and reliable judgment even when used for the first time and to be able to easily distinguish between positive and negative. By the way, as an in-vitro diagnostic agent utilizing an antigen-antibody reaction such as a pregnancy diagnostic agent for OTC, a development type utilizing chromatography is mainly used.

The principle of such a deployable in-vitro diagnostic agent is shown in the following (1) to (3). A sample is provided from one end of a developing substrate having a good water absorption property such as a porous membrane or a filter paper, and the sample is developed on the substrate. A labeled material of an antibody against the detected substance is impregnated into a base material that is integrated with the development base material or is separate from the development part to form an antigen-antibody complex with the developed specimen.

Then, such an antigen-antibody complex is trapped by an antibody having an epitope different from that of the labeled antibody fixed at the positive judgment position of the above-mentioned development base material and is confirmed as a color. In this system, an antibody against the labeled antibody or a substance that specifically binds to the labeled antibody is usually fixed as a negative determination position behind the positive determination position so that the end of the determination can be confirmed.

Such a chromatographic in-vitro diagnostic agent has advantages that it is easy to operate and easy to handle even by an amateur. However, on the other hand, the diagnostic drug generally has a slow development time (normally 1 to 5 minutes until the end of the judgment), and if it is not judged within a strict judgment time, the background changes with time. Therefore, there is a drawback that it is easy to make a wrong decision.

Further, the current in-vitro diagnostic agents tend to end the coloration of the negative site before the coloration of the positive site is visually confirmed, so that the above-mentioned termination sign does not make sense. To be

[0007]

The problem to be solved by the present invention is, therefore, a means for displaying the approximate time lapse or the original end time on a chromatographic expansion type OTC diagnostic agent in order to solve the above problems. Is to provide.

[0008]

Means for Solving the Problems As a result of intensive studies for solving the above-mentioned problems, the present inventor has provided a composition for an indicator for displaying a lapse of time and a time indicator using the composition. We came to solve the problem. That is, the present invention is a color reagent, a binder,
A composition for an indicator, comprising a water-absorbent powder and a pH buffer as main components.

Here, the indicator composition contains 0.05 to 5% by weight of a coloring reagent, 0.5 to 10% by weight of a binder, 20 to 70% by weight of a water-absorbing powder, and 0 to 0% of a pH buffering agent. It is preferably contained in the range of 20% by weight. Furthermore, the present invention is a time indicator characterized by coating or impregnating the above-mentioned indicator composition on a support.

The present invention will be described in detail below. A. Regarding the composition for an indicator of the present invention: As described above, the composition for an indicator of the present invention mainly comprises a color reagent, a binder, a water-absorbing powder and a pH buffering agent. As the color reagent, a substance that changes color by contact with a liquid or a substance that changes color tone by sensing a component that is always present in body fluid is used.

Examples of the substance that changes its color by contacting with the former liquid are so-called wetting detection reagents such as sodium fluorescein and cobalt chloride; or alkaline salts of bromthymol blue, which is a pH indicator, bromophenol blue and phenol. For example, phthalein is used. Examples of the latter substance that exhibits a color change upon sensing a component that is always present in the body fluid include tetrabromophenol blue, bromothymol blue, tetrabromobenzaniline, and tetrabromothymol blue.

The content in the composition is preferably 0.05 to 5% by weight, and the former is preferably fluorescein sodium and the latter is tetrabromophenol blue from the viewpoint of high sensitivity in the reagent and large contrast of color tone change. The binder is required to have no influence on the pH in the body fluid and to prevent the reagent reaction. As the binder satisfying such requirements, polyester resin, polyurethane resin, polystyrene resin, acrylic resin, vinyl chloride resin, PVB resin, PVA resin, PVP resin, maleic anhydride type copolymer resin, etc .; hydroxypropyl cellulose , Methylcellulose, ethylcellulose, carboxymethylcellulose and other cellulosic resins; starch,
Natural polymers such as casein are used.

The binder also acts as a viscosity modifier, and the water absorption rate of the time indicator described later can be changed by changing the composition and amount of the binder. That is, if a water-soluble binder is contained, the binder melts when the liquid passes through the time indicator, and the liquid becomes viscous, but if the amount of the binder is increased, the viscosity increases.
The liquid slows down and the time to reach a certain distance becomes longer.

Considering the above conditions and ink suitability of the time indicator composition, 0.5 to 10% by weight is desirable. Also, as a binder, the ink suitability is not impaired,
PVP, PVB and hydroxypropyl cellulose, which have good compatibility with the powder component, are preferable. When added to the indicator composition of the present invention, the water-absorbing powder enhances the water absorption of the composition provided on the support and plays a role as a filler for the composition.

As such a water-absorbing powder, it is preferable that the powder does not affect the pH of the reagent composition when it comes into contact with water and has a high whiteness. Examples of the substance which becomes the material of the water-absorbing powder satisfying such conditions include microcrystalline cellulose, hydroxypropyl cellulose, carboxymethyl cellulose calcium, ion exchange cellulose, ion exchange resin, kaolin, synthetic silica, hydroxyapatite and the like. In view of its high water absorption property, microcrystalline cellulose, hydroxypropyl cellulose and carboxymethyl cellulose calcium are preferable.

Further, in consideration of ink suitability when applied to a support, a spherical shape and a uniform particle size are desirable. The particle size of the water-absorbent powder can be in the range of 180 μm or less, preferably 10 to 50 μm. The flow rate of the time indicator can be adjusted by the water absorbing performance of the water absorbing powder, the particle size and the composition ratio.

The flow velocity changes depending on the water absorption performance of the water-absorbing powder, and it is possible to measure an arbitrary time by combining powders having different water-absorbing properties. In addition, the porosity of the time indicator is changed depending on the particle size (when the particle size is small, the porosity decreases), which affects the flow velocity. The water-absorbing powder is preferably present in 20 to 70% by weight based on the solid weight of the ink composition.

The pH buffering agent is used to maintain the pH value at which the above-mentioned coloring reagent causes a preferable color change in the time indicator composition. Such pH buffers include citric acid, sodium citrate, sodium acetate,
A mixture of a plurality of adipic acids, tris, ammonium carbonate, etc. is used. In addition, carboxymethyl cellulose, carboxymethyl cellulose calcium,
Powders of sodium polyacrylate and polyvinyl alcohol copolymer can also be used as a solid buffer. The pH to be maintained is set according to the type of color reagent used.

These buffers are used in a state in which the solvent is dissolved or uniformly dispersed. When the solvent is water, usually the buffer is dissolved, in the case of an organic solvent such as butyl cellosolve, amyl alcohol, first, the buffer is pulverized and dispersed in the solvent to prepare a slurry, Dissolve the slurry in the other ink ingredients.

The content of the pH buffer in the indicator composition is preferably 0 to 20% by weight. The solvent is preferably one that can dissolve or disperse the above reagents uniformly and stably. As a solvent satisfying this condition,
Examples thereof include non-aqueous solvents such as aromatic hydrocarbons, aliphatic hydrocarbons, esters and alcohols, water, and mixtures of water with the above non-aqueous solvents.

As other components, in addition to the above-mentioned components, a small amount of wetting agent, for example, a nonionic surfactant, polyethylene glycol or the like can be added to the indicator composition of the present invention. In the method for preparing such a composition, the color reagent is completely dissolved, then the buffer component and the binder are thoroughly mixed with a spatula, and then the powder is added little by little and kneaded well using an agitator. B. The Time Indicator of the Present Invention The time indicator of the present invention is characterized by coating or impregnating the above-mentioned indicator composition on a support.

The support is not particularly limited as long as it is a base material that does not affect the components in the indicator composition. Specifically, films of polystyrene, polyethylene terephthalate, polypropylene, polyvinyl chloride, ABS resin, polycarbonate, etc .; cellulose, glass fiber filter paper, nylon, nitrocellulose, PVDF, etc., which are usually used as a base material for the judgment part of inspection materials. It is also possible to use a non-woven fabric such as a porous film or polyester or nylon.

When the detection reagent is directly applied to a porous membrane or a non-woven fabric coated / impregnated with the detection reagent, the presence of water-soluble components in the time indicator hinders the migration of the sample to the detection part and the time indicator area Bleeding can be a problem. In such a case, it is also possible to provide a single waterproof layer on the support and apply the time indicator thereon. When the support is a film, it can be used by providing an adhesive layer on the side opposite to the color-coated surface and attaching it to the film.

Further, the ink composition is prepared by kneading the respective components,
The time indicator area is formed by applying it as an ink on the support. As the coating technique, various printing methods such as screen printing method, intaglio printing method and gravure printing method, and various coating methods such as roll coating method, spray coating method and dip coating method can be used. In the present invention, it is preferable that the amount of ink composition applied is relatively large and the amount applied is constant. Therefore, among the above, it is preferable to use a printing method such as a screen printing method, an intaglio printing method, or a gravure printing method.

Further, it is possible to provide one end of the time indicator with an absorbing portion for stably supplying the sample. The absorbing part is required to be made of a material having high water absorption and high water retention. As a material of such an absorbing portion, a cellulose filter paper, a glass fiber bonded together,
It is possible to use a coating product obtained by dispersing and kneading an organic solvent and a binder in a superabsorbent resin such as cellulose-based powder, sodium polyacrylate / sodium polyacrylate / polyvinyl alcohol copolymer, and the like.

Further, the absorbing portion has a cross-sectional area larger than the cross-sectional area of the time indicator in the width direction, and it is preferable that the time contact with the time indicator is capable of absorbing a larger amount of the sample. Further, the time indicator obtained by appropriate drying can be examined for its water absorption rate by actually immersing it in water.
Depending on the result, it is possible to provide a scale or a character on the water reaching portion at any time.

Generally, the water absorption rate due to the capillarity changes depending on the viscosity of the liquid and the salt concentration, but the water absorption rate does not change within the range of individual difference of human body fluid. The subject can know the examination time of the examination by observing the arrival position of the color tone change of the time indicator. By providing the time indicator of the present invention as a reaction completion sign for various diagnostic agents on a material having a known water absorption performance, it is possible to make a determination with an appropriate reaction time.

By applying this time indicator in a line from the urine collecting part of the expandable diagnostic agent in parallel to the expanding direction, it is possible to supply the sample to the judging part and at the same time to know the time lapse in real time. Furthermore, since the time indicator is formed by applying the ink component, the installation process is simple and can be installed in any size. Moreover, since the developing speed can be adjusted depending on the substrate or ink composition used, it is possible to deal with various test agents.

[0029]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the technical scope of the present invention is not limited by these examples. [Example 1] A time indicator composition having the following composition was refined and dispersed in a slurry as a pretreatment product by using a sieve, a crusher, and a ball mill as described above, and then kneaded with an agitator to obtain a time indicator. The composition constituted.

Units: wt% Tetrabromophenol blue 0.14 Sorbitan monooleate 1.00 Citric acid 2.52 Sodium citrate 1.08 Methyl vinyl ether / maleic anhydride copolymer esterified product with amyl alcohol 1.14 Polyvinyl butyral 0.18 Hydroxypropyl cellulose 0.74 Triethyl citrate 0.28 Low-substituted hydroxypropyl cellulose 8.00 Microcrystalline cellulose (Asahi Kasei, Avicel M15) 20.00 Carboxymethyl cellulose 1.60 Carboxymethyl cellulose calcium 10.40 Butyl Cersolve 30.00 Butyl Cersolve Acetate 20.00 Amyl Alcohol 3.00 After sufficiently kneading the above composition with an agitator, a screen printing method was performed to obtain the composition shown in FIG. As shown in Fig. 25, polyethylene terephthalate (PE
T) 2 mm wide and 100 mm long on the film (PET support 8)
Printed so that the stick-shaped, and the film thickness when dried will be 50 μm.
C., and dried for 10 minutes. From the tip to this PET support 8
I printed the letter "end" and a scale at 100mm.
After that, this was cut into 3 mm x 120 mm and placed on a glass fiber paper 1 consisting of a development part 3 for pregnancy diagnostics, an absorption part 2, a colloidal gold impregnation part 4 and an antibody fixing part (positive judgment part 5 and negative judgment part 6). Affixed, a pregnancy diagnostic drug with a time indicator 7 was prepared.

When a pregnant subject examined this by applying urine, the time indicator portion of the sample urine became wet at 20 mm / min, and the color tone of the time indicator portion changed from yellow to green with the wetness. . The time to reach the reaction completion scale was about 5 minutes. On the other hand, the pregnancy determination part absorbed water at a water absorption rate of 80 mm / min, and after the gold colloid developed, positive and negative lines clearly appeared, and the reaction was completed after about 5 minutes. [Example 2] A time indicator composition having the following composition was refined as described above by using a sieve, a crusher, and a ball mill.
Then, the product was dispersed into a slurry to prepare a pretreatment product, and then kneaded with an agitator to prepare a time indicator composition.

Unit: wt% Sodium Fluorescein 0.14 Butylcellosolve 20.00 Butylcellosolve acetate 20.00 Hexanol 11.40 PVP 0.34 Polyvinyl butyral 2.82 Triethyl citrate 0.46 Avicel 32.00 Hydroxypropyl Cellulose 8.00 or more composition was sufficiently kneaded and then screen-printed to obtain water-dispersible paper 9 (manufactured by Mishima Paper Co .; CD
-2N), a time indicator 7 was printed so as to have a width of 2 mm and a length of 40 mm and a thickness of 50 μm, and dried at 70 ° C. for 40 seconds.

As shown in FIG. 2, a developing part 3 and an absorbing part 2 are provided by screen printing, and further a gold colloid impregnating part 4, a positive judging part 5 and a negative judging part 6 are provided, 1 μl of anti-LH antibody and gold colloid sensitization. 10 μl anti-LH antibody, 1 μl anti-human IgG antibody
Was dropped and fixed. Printed sheet width 10mm, length 50mm
Cut into When the absorption rate of the time indicator 7 was measured in advance, the water absorption rate was 8 mm / min.

When a performance test was carried out using pregnant woman's urine, the color of the time indicator 7 changed from white to yellow with water absorption, and the whole turned yellow in 5 minutes. on the other hand,
The pregnancy determination part absorbs at 120 mm / min, and the negative determination part 6 in about 5 minutes
-The positive determination part 5 was colored and the reaction was completed.

[0035]

According to the present invention, chromatographic expansion type OTC
An indicator is provided which is provided with a means for displaying a lapse of time or an original termination sign to the diagnostic agent for use.

[Brief description of drawings]

FIG. 1 is an overall view of a time indicator of the present invention shown in a first embodiment.

FIG. 2 is an overall view of a time indicator of the present invention shown in a second embodiment.

[Explanation of symbols]

1: Glass fiber paper 2: Absorption part 3: Development part 4: Gold colloid impregnation part 5: Positive judgment part 6: Negative judgment part 7:
Time indicator 8: PET support 9: Water dispersible paper

Claims (3)

[Claims] 1. A composition for an indicator, which comprises a coloring reagent, a binder, a water-absorbing powder and a pH buffer as main components. 2. The coloring reagent is 0.05 to 5% by weight, and the binder is 0.1%.
The composition for an indicator according to claim 1, wherein the content of the water-absorbing powder is 5 to 10% by weight, the content of the water absorbing powder is 20 to 70% by weight, and the pH buffering agent is 0 to 20% by weight. 3. A time indicator comprising a support and the indicator composition according to claim 1 applied or impregnated on the support.