Abstract: A backstop device to prevent inadvertent withdrawal of a stopper or plunger rod from the open distal end of a flangeless syringe barrel. The backstop includes a retaining wall configured to engage at least a portion of the syringe barrel, and a finger plate at the proximal end of the retaining wall. The finger plate includes an aperture adjacent the open proximal end of the syringe through which a stopper may be inserted. If desired, a ridge may be formed around the periphery of the aperture which may engage with a portion of the syringe barrel. The aperture and, if present, the ridge present a smaller passageway than the inside diameter of the syringe, preventing inadvertent removal of the stopper from the syringe. The backstop can be placed on the syringe regardless of the presence or absence of the plunger.

Abstract: A syringe assembly includes a substantially cylindrical syringe barrel and a plunger assembly. The plunger assembly includes a distally disposed flow channelizer and a proximally disposed stopper releasably engaged with one another. The stopper includes an aperture engageable with the distal end of a plunger rod. The flow channelizer includes flutes for accommodating an outflow of vapor during lyophilization and to enable efficient mixing of a lyophilized medication and a diluent. Liquid medication in the syringe chamber is lyophilized and a vacuum is applied to the syringe barrel. The plunger assembly then is urged distally into sealing engagement with the syringe barrel. A plunger rod is engaged with the stopper, and is moved proximally to simultaneously separate the stopper from the flow channelizer and to draw diluent into the chamber for reconstituting the previously lyophilized medication.

Abstract: A syringe having structure to isolate fluid from the distal end of the syringe includes a barrel with a chamber therein. A stopper is slidingly disposed in the chamber and is provided with an aperture extending axially therethrough. A plug includes a head releasably engaged in a sealing portion of the aperture of the stopper. A rigid tail extends distally from the head and through the aperture in the stopper and projects outwardly from the distal end of the stopper. The tail is long enough so that it can be used to move the head out of the sealing portion of the aperture by applying force to the distal end of the tail. The tail has a cross-sectional shape which defines at least one fluid channel between the tail and the sealing portion of the stopper to allow fluid to flow from the chamber through the aperture in the stopper and out of the distal end of the barrel.

Abstract: A two-component syringe includes a barrel having a chamber for retaining fluid and a distal end of the barrel having a passageway therethrough communicating with the chamber. A by-pass stopper is slidably positioned in fluid-tight engagement inside the barrel. The stopper has a distal rib contacting the barrel, a recess on the proximal side of the rib and a groove in the rib for allowing fluid communication between the recess and the chamber. This groove is positioned angularly with respect to the longitudinal access of the barrel so that liquid passing therethrough is directed angularly with respect to the longitudinal axis of the barrel. The barrel also includes a raised peripheral portion serving as a by-pass and defining a by-pass zone. The by-pass zone is shorter than the length of the stopper along the longitudinal axis of the barrel.

Abstract: A vacuum cleaner is provided with an improved filter bag which is attached to a fixed part of the vacuum cleaner by a removable base member. The base member is adapted to allow the ingress and egress of a pipe which transports a gaseous fluid to be filtered, to the interior of the bag. Seal means are also provided for holding the pipe in sealing engagement with the base member and bag.