Viscoelastic memory means and flow control valve and use thereof to produce a single-use, auto-destruct injection device

摘要

Solid disks of polyethylene oxide are radiation crosslinked to instill viscoelastic memory. The disks are then pierced with a needle, heated, cooled and the needle removed to form disks containing a flow orifice in each which upon contact with water will revert to solid disks. A disk with a flow orifice made as just described when used as a memory flow control valve in a conventional injection device will produce a syringe with a single-use, auto-destruct capability. When the disk is inserted in a retainer in the flow channel of the injection device, a drug/vaccine can be drawn into the syringe and then expelled for a preselected time less than six minutes before the water in the drug/vaccine causes the flow orifice in the disk to close, the disk then reverting to its solid shape due to its viscoelastic memory.