Noninvasive Transdermal Systems for Detecting an Analyte in a Biological Fluid and Methods

Abstract

The present invention relates to noninvasive transdermal systems comprised of a noninvasive transdermal patch and a reflectometer. The noninvasive transdermal patches are comprised of a wet chemistry component and a dry chemistry component. The wet chemistry component is a liquid transfer medium in the form of a gel layer for the extraction and liquid bridge transfer of the analyte of interest from the biological fluid within or beneath the skin to the dry chemistry component. The dry chemistry component is a reagent system for interacting with the analyte of interest (glucose) to generate a color change. The reflectometers include a modulated light source for emitting light to illuminate a target surface which possesses a certain color and shade of color for detection by an optical detector. The output signal is processed for determining a corresponding quantity of quality measurement.

Description

FIELD OF THE INVENTION[0001]The present invention concerns noninvasive transdermal systems and methods for analyte extraction from a biological fluid within or beneath the skin, such as interstitial fluid, and detection of the analyte. More particularly, the present invention relates to noninvasive transdermal systems comprised of a noninvasive patch and a reflectometer for detecting an analyte of interest and methods. The noninvasive patches include a wet chemistry component for extraction of the analyte of interest from a biological fluid within or beneath the skin and presentation to a dry chemistry component which interacts with the analyte for indicator molecule formation to confirm detection of the analyte, and methods of use thereof.[0002]The present invention also relates to reflectometer technology and, in particular, to a method and apparatus for detecting and measuring color shades with a relatively high degree of accuracy. Where the color shades are indicative of a certa...

AI Technical Summary

Benefits of technology

The present invention provides a noninvasive transdermal system for detecting analytes of interest in biological fluids without the need for painful and invasive techniques. The system consists of a dry chemistry component and a wet chemistry component, which are integrated into a single device for easy use. The super sensitive membrane of the system is designed to detect small amounts of analyte in small sample volumes. The system includes a gel layer or gel matrix for liquid transfer or extraction of the analyte from the skin. The gel layer includes a permeation skin enhancer to enhance the transfer of the analyte from the skin. The noninvasive transdermal system can be used as a component of a noninvasive transdermal patch for easy collection and detection of analytes in biological fluids.

Problems solved by technology

Some attempts to use infrared techniques to look through the skin to make blood sugar determinations have proven to be less reliable and too expensive for commercial application.

Unfortunately, the current methods of monitoring blood glucose levels has many drawbacks.

The current methods generally rely upon finger lancing to monitor blood glucose levels, which is not easy for anyone, especially young children and the elderly.

Moreover, because blood is involved, there is always the risk of infection and of transmission of blood borne diseases, such as AIDS.

If the blood glucose concentrations in such individuals are not properly maintained, the individuals become susceptible to numerous physiological problems, such as blindness, circulatory disorders, coronary artery disease, and renal failure.

Ethyl ether, however, is a known skin irritant which is flammable and explosive.

However, these techniques generally require invasive methods to draw a blood sample from a subject; typically, blood must be drawn several times a day by a finger prick, such as presently employed by a diabetic and externally determining the glucose level, generally by chemical reaction followed by colorimetric comparative testing.

Because the prior art invasive techniques are painful, individuals frequently avoid having blood glucose measured.

For diabetics, the failure to measure blood glucose on a prescribed basis can be very dangerous.

Also, the invasive techniques, which rely upon lancing blood vessels, create an enhanced risk for disease transmission and infection.

However, with respect to transdermal detection mechanism, the extracted analytes which are indicative of widely varying blood sugar levels may produce only very slight changes in developed color shade.

In many instances, the difference between developed color shade for an acceptable and an unacceptable blood sugar level cannot be accurately and repeatably detected by the naked eye.

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