Intradermal injection device

Abstract

An intradermal injection device comprising a unitary body having an open distal end and a proximal end having a skin engaging surface defined thereon, a reservoir defined between the proximal and distal ends for accommodating a drug substance, and a channel defined at the proximal end of the unitary body and extending through, and distally from, the skin engaging surface to the reservoir. A needle cannula having a sharpened proximal end and a distal end may be provided in the channel. The needle cannula is secured in the channel with the distal end being in communication with the reservoir and the proximal end of the needle cannula extending from the skin engaging surface a distance in the range of about 0.5 mm to 3.0 mm such that the skin engaging surface limits penetration of the proximal end of the needle cannula to the dermis layer of the skin of a patient.

Description

[0001] This application claims priority to U.S. Provisional Application No. 60 / 498,508, filed Aug. 28, 2003.FIELD OF THE INVENTION [0002] The present invention relates to an intradermal injection device. BACKGROUND [0003] Drug substances may be delivered into a patient's body via injection into the muscle, subcutaneous tissue, or into the epidermis and dermis (also referred to as an intradermal injection). The efficacy of a particular drug substance may change when the drug is delivered intradermally. In some cases, intradermal delivery may be more beneficial to the patient. There is considerable variation in the skin thickness both between individuals and within the same individual at different sites of the body. Generally, the outer skin layer epidermis has a thickness of ranging from 50 to 200 microns, and the dermis, the inner and thicker layer of the skin, has a thickness ranging from 1.5 to 3.5 mm. Therefore, a needle cannula that penetrates the skin deeper than about 3 mm has...

AI Technical Summary

Benefits of technology

[0007] In a further aspect of the subject invention, a protrusion is provided on the proximal end of the body of the device which extends proximally from a first surface portion. Preferably, the protrusion is annular and circumscribes the channel. The protrusion aides in the injection process by providing a good interface between the device and the patient's skin, limiting leakage from the injection site during the injection process.

Problems solved by technology

Therefore, a needle cannula that penetrates the skin deeper than about 3 mm has a potential of passing through the dermis layer of the skin, thus making the injection into the subcutaneous region, which may result in an insufficient immune response, especially where the substance to be delivered intradermally has not been indicated for subcutaneous injection.

Also, the needle cannula may penetrate the skin at too shallow a depth to deliver the substance and result in what is commonly known in the art as a “wet injection” due to reflux of the substance from the injection site.

The standard procedure for making an intradermal injection, generally referred to as the Mantoux procedure, is difficult to perform, and successful administration of an intradermal injection using that procedure depends upon experience and technique of the person using the injection device.

The above-described technique is difficult to perform and typically requires the attention of a trained nurse or medical doctor.

Inserting the needle to a depth greater than about 3 mm typically results in a failed intradermal injection because the drug substance being expelled through the cannula will be injected into the subcutaneous tissue of the patient.

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