Abstract: A needleless syringe particle delivery system is provided. The needleless syringe has an elongate nozzle that is connected at its upstream end to a sealed chamber. The sealed chamber contains gas at super-atmospheric pressure and particles of a therapeutic agent. Upon release of the gas from the sealed chamber, a flow is formed which entrains the particles and allows the particles to pass through the nozzle at supersonic speed for subsequent delivery to a target surface.

Abstract: A method is provided for in vivo or ex vivo delivery of a preparation of powdered nucleic acid molecules into vertebrate tissue for transformation of cells in the tissue using needleless injection techniques. The method can be used to deliver therapeutically relevant nucleotide sequences to cells in mammalian tissue to provide gene therapy, elicit immunity or to provide antisense or ribozyme functions. A method for providing densified processed pharmaceutical compositions is also described. The method is used to convert non-dense pharmaceutical powders or particulate formulations into densified particles optimally suited for transdermal delivery using a needleless syringe. The method is also used to optimize the density and particle size of powders and particulate formulations for subsequent transdermal delivery thereof. Densified pharmaceutical compositions formed by the present methods are also provided.

Abstract: A needleless syringe particle delivery system is provided. The needleless syringe comprises an elongate nozzle which is connected at its upstream end to an open ended capsule chamber. The capsule chamber is configured to house and intimately enclose a nonrigid capsule containing particles of a therapeutic agent. An opening means is provided at the upstream end of the capsule chamber, and is used to pierce the upstream end of a capsule in the chamber. After the capsule is opened, an energizing means connected to the upstream end of the capsule chamber applies a gaseous pressure sufficient to force the particles out of the capsule and the open downstream end of the capsule chamber and thus to create through the nozzle a supersonic gas flow in which the particles are entrained.

Abstract: A needleless syringe capable of accelerating particles comprising a therapeutic agent across skin or mucosal tissue of a vertebrate subject is provided. The syringe comprises an elongate tubular nozzle having a bend along its length and is connected to or capable of connection to a suitable energizing means for producing in the nozzle a supersonic condition sufficient to cause delivery of the particles to a target surface. A method for delivering particles comprising a therapeutic agent from the needleless syringe is also provided.