US 7,320,677 B2
Needleless syringe for the delivery of therapeutic agents
Martin Brouillette, Sherbrooke (Canada)
Assigned to Société de Commercialisation des Produits de la Recherche Appliquée - Socpra Sciences et Génie, S.E.C., Sherbrooke, Quebec (Canada)
Appl. No. 10/398,855
PCT Filed Oct. 19, 2001, PCT No. PCT/CA01/01491
§ 371(c)(1), (2), (4) Date Aug. 15, 2003,
PCT Pub. No. WO02/32483, PCT Pub. Date Apr. 25, 2002.
Claims priority of application No. 2324045 (CA), filed on Oct. 20, 2000.
Prior Publication US 2004/0024350 A1, Feb. 05, 2004
Int. Cl. A61M 5/30 (2006.01)
U.S. Cl. 604—68  [604/69] 51 Claims
OG exemplary drawing
 
1. A needleless syringe for delivering therapeutic particles to a skin surface, comprising:
a gas reservoir for receiving a gas at a first pressure, the gas reservoir having a first internal diameter and an opening;
an elongate tubular nozzle having an upstream end mounted to the opening of the gas reservoir, an upstream portion and a downstream end;
an arrangement comprising:
the elongate tubular nozzle having a generally constant second internal diameter smaller than the first internal diameter and being at a second internal a pressure;
a contraction of the gas reservoir from the first internal diameter to the second internal diameter;
a source of therapeutic particles positioned in the upstream end of the elongated tubular nozzle of generally constant second internal diameter; and
a partition for separating the gas reservoir from the source of particles, the partition being designed to be opened and to withstand large pressure differences between the gas reservoir and the elongate tubular nozzle; and
wherein the first and second internal diameters and the first and second gas pressures define respective, predetermined diameter and pressure ratios adapted to produce, in response to opening of the partition, a gaseous expansion generating a) a stationary expansion wave in the contraction leading to a sonic flow at the upstream end of the tubular nozzle and b) non-stationary expansion waves traveling downstream in the elongate tubular nozzle to carry the therapeutic particles into a supersonic gas flow and deliver the therapeutic particles to the skin surface through the downstream end of the tubular nozzle.