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Single-use, self-annulling injection syringe

  • US 4,781,683 A
  • Filed: 04/22/1987
  • Issued: 11/01/1988
  • Est. Priority Date: 04/22/1987
  • Status: Expired due to Term
First Claim
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1. A single use injection device, comprising:

  • a variable volume chamber adapted to receive a drug containing water;

    an injection needle having an internal lumen, said injection needle connected to said variable volume chamber forming a flow channel between said variable volume chamber and said internal lumen of said injection needle; and

    a hydrophilic expansion means composed essentially of a hydrogel, positioned within said flow channel, for expanding and blocking said flow channel after being exposed to said drug containing water, thereby preventing reuse of the injection device, wherein said hydrophilic expansion means comprises a delay means for providing a preset time window greater than thirty seconds from the time of exposure of said hydrophilic expansion means to said drug containing water for injection of the drug before the hydrophilic expansion means blocks said flow channel.

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