Needleless injection device with double stopper with low pressure profiles

Inventors

Alexandre, Patrick

Abstract

The present invention relates to a needleless injection device (1) comprising a reservoir (3), obturated by an upstream stopper (4) and a downstream stopper (5) between which a liquid active principle (6) is accommodated, and a receptacle (7) comprising at least one injection conduit (8), said receptacle comprising a cavity (10) whose height is equal to the distance traveled by the downstream stopper before each injection conduit is opened, —the height of the cavity in millimeters being between a minimum height and a maximum height, respectively defined by the following relationships, •minimum height=3, •maximum height=15×exp. (−(V/9)2)+10, where V is the initial speed of ascent of the pressure profile expressed in bar per microsecond, —the ratio between the length of each injection conduit and the height of the cavity being between 1 and 2.

Core Innovation

The invention relates to a needleless injection device having a body with a first end and a second end, an energy source adjacent the first end, and a reservoir blocked by a movable upstream stopper and a movable downstream stopper with a liquid active principle housed between the stoppers. The device further includes an injection nozzle adjacent the second end, equipped with a receptacle and at least one injection duct.

The receptacle contains a cavity whose height equals a distance covered by the movable downstream stopper before opening each injection duct, and the cavity height in millimeters is constrained between minimum and maximum heights defined as functions of a speed of an initial increase in a pressure profile expressed in bars per microsecond. A ratio between a length of each injection duct and the height of the cavity is between 1 and 2.

The device is configured to manage shockwave and speed limits in double-stopper systems while reducing operating pressure, using the cavity-height selection and duct geometry to obtain improved injection performance. Documented configurations include an energy source as a pyrotechnic gas generator with a pyrotechnic charge and an ignition system, and embodiments where reservoir stoppers and the receptacle geometry cooperate with multiple injection ducts and defined pressure-profile behavior.

Claims Coverage

The independent claims are directed to a needleless injection device with a double-stopper liquid reservoir and an injection nozzle receptacle whose cavity opening timing is tied to downstream stopper travel. Across the independent claims, the inventive features include an energy source positioned at the device end(s), a movable upstream/downstream stopper reservoir arrangement, a receptacle cavity configured to define when injection ducts open, and quantitative constraints on cavity height as a function of a pressure-profile-derived initial pressure ascent speed V, together with a duct-length-to-cavity-height ratio constraint.

Across the independent claims, the core inventive concept is the coupling of a double-stopper reservoir to an injection nozzle receptacle whose cavity height and geometry are constrained using exponential functions of V and a duct-length-to-cavity-height ratio. The claims center on the stopper-to-cavity configuration and the V-based cavity/duct geometry constraints.

Stated Advantages

Documented Applications