Claims for Patent: 6,881,200

Summary for Patent: 6,881,200

Title:	Needleless syringe using super sonic gas flow for particle delivery
Abstract:	A needleless syringe having a membrane (28) which is ruptured by gas pressure to generate a supersonic gas flow in which particles containing a therapeutic agent are injected.
Inventor(s):	Bellhouse; Brian J. (Islip, GB), Sarphie; David F. (Oxford, GB), Greenford; John C. (Abingdon, GB)
Assignee:	PowderJect Research Limited (Oxford, GB)
Application Number:	09/248,743
Patent Claims:	1. A sealed unit for use with a needleless syringe, the unit comprising first and second rupturable diaphragms which are directly or indirectly sealed to each other around their edges to form a compartment which contains particles of a powdered therapeutic agent, wherein at least one of said first and second diaphragms is constructed from a material having a burst pressure of between 20 and 75 atmospheres in a pressure chamber having a volume of between 1 and 5 ml, whereby said at least one diaphragm is rupturable by a flow of gas to initiate a gas flow through said sealed unit. 2. The unit of claim 1, in the form of a sealed rupturable sachet or capsule. 3. The unit of claim 2, further comprising a third diaphragm disposed between the first and second diaphragms to provide at least two compartments containing different powdered therapeutic agents. 4. The unit of claim 1 in which the powdered therapeutic agent is a stable mixture of drugs which are unstable when mixed wet. 5. The unit of claim 1 in which the therapeutic agent comprises insulin. 6. The unit of claim 1 in which the particles have a size predominantly in the range of 0.1 to 250 .mu.m. 7. A product according to claim 6, wherein the size range is 1 to 50 .mu.m, preferably 10 to 20 .mu.m. 8. A sealed capsule for use in a needleless syringe, wherein said capsule contains a dose of a powdered agent and has a burst pressure of between 20 and 75 atmospheres in a pressure chamber having a volume of between 1 and 5 ml, whereby said capsule will release the powdered agent for transdermal delivery thereof when said capsule is contacted with a source of pressurized gas. 9. The sealed capsule of claim 8 wherein said capsule comprises at least one membrane which retains the powdered agent within the capsule prior to contact with a source of pressurized gas. 10. The sealed capsule of claim 8 wherein the powdered agent is comprised of particles having a size predominantly in the range of 0.1 to 250 .mu.m. 11. The sealed capsule of claim 10 wherein the particles have a size predominantly in the range of about 10 to 20 .mu.m.