| abstract |
Solid discs of polyethylene oxide are crosslinked by radiation, which gives them a visco-elastic memory. The discs are then pierced using a needle, heated and cooled; then the needle is removed, so that one obtains discs each containing a flow orifice and which, in contact with water, will again become solid discs. A disc comprising a flow orifice produced as described above and used as a memory flow regulator in a conventional injection device makes it possible to obtain a syringe for single use and self-destructing. When the disc (1b) is inserted into a retainer (10) in the flow channel (12) of the injection device, a drug / vaccine can be drawn into the syringe and then ejected in a preselected time, less ten minutes before the water in the medication or vaccine causes the disc orifice to close, after which the disc will return to its solid form due to its visco-elastic memory. |