Abstract: A method for determining predicted failure rates of drug injection devices includes receiving a set of parameters specifying physical properties of a syringe, a liquid drug, and a drug injection device configured to deliver the liquid drug to a patient via the syringe, the drug injection device including a mechanism that drives a plunger rod toward a plunger of the syringe encased in a syringe carrier. The method also includes receiving failure rate data specifying a measured rate of failure of the drug injection device in response to various peak pressures within the syringe, applying the set of parameters to a kinematic model of the drug injection device to determine a predicted peak pressure within the syringe, determining a probability of failure of the drug injection device using the failure rate data and predicted peak pressure, and providing an indication of the determined probability of failure to an output device.

Abstract: Impact testing apparatuses are disclosed which simulate and measure various impact-related events associated with the operation of a drug delivery device. The impact testing apparatus may include an impactor configured to simulate a plunger rod of the drug delivery device, and a guide sleeve configured to receive a syringe corresponding to the drug delivery device. The syringe may have a proximal end, a distal end defining an outlet, and an interior chamber extending between the proximal and distal ends and carrying a plunger. Additionally, the impact testing apparatus may include an energy source configured to reduce a distance between the impactor and the plunger so that the impactor strikes the plunger. Various sensors may be included to measure characteristics of one or more impacts caused by the impactor. Methods of impact testing a syringe filled with a fluid and carrying a plunger are also disclosed.

Abstract: Impact testing apparatuses are disclosed which simulate and measure various impact-related events associated with the operation of a drug delivery device. The impact testing apparatus may include an impactor configured to simulate a plunger rod of the drug delivery device, and a guide sleeve configured to receive a syringe corresponding to the drug delivery device. The syringe may have a proximal end, a distal end defining an outlet, and an interior chamber extending between the proximal and distal ends and carrying a plunger. Additionally, the impact testing apparatus may include an energy source configured to reduce a distance between the impactor and the plunger so that the impactor strikes the plunger. Various sensors may be included to measure characteristics of one or more impacts caused by the impactor. Methods of impact testing a syringe filled with a fluid and carrying a plunger are also disclosed.

Abstract: Impact testing apparatuses are disclosed which simulate and measure various impact-related events associated with the operation of a drug delivery device. The impact testing apparatus may include an impactor configured to simulate a plunger rod of the drug delivery device, and a guide sleeve configured to receive a syringe corresponding to the drug delivery device. The syringe may have a proximal end, a distal end defining an outlet, and an interior chamber extending between the proximal and distal ends and carrying a plunger. Additionally, the impact testing apparatus may include an energy source configured to reduce a distance between the impactor and the plunger so that the impactor strikes the plunger. Various sensors may be included to measure characteristics of one or more impacts caused by the impactor. Methods of impact testing a syringe filled with a fluid and carrying a plunger are also disclosed.

Abstract: A method for determining predicted failure rates of drug injection devices includes receiving a set of parameters specifying physical properties of a syringe, a liquid drug, and a drug injection device configured to deliver the liquid drug to a patient via the syringe, the drug injection device including a mechanism that drives a plunger rod toward a plunger of the syringe encased in a syringe carrier. The method also includes receiving failure rate data specifying a measured rate of failure of the drug injection device in response to various peak pressures within the syringe, applying the set of parameters to a kinematic model of the drug injection device to determine a predicted peak pressure within the syringe, determining a probability of failure of the drug injection device using the failure rate data and predicted peak pressure, and providing an indication of the determined probability of failure to an output device.

Abstract: A drug delivery device includes a reservoir, a drug delivery member in fluid communication with the reservoir, and a plunger disposed in and moveable relative to the reservoir. A plunger rod has a mass MP and is movable from (i) a first position, where the distal end of the plunger rod is spaced apart from the plunger to (ii) a second position, where the distal end of the plunger rod contacts the plunger. A drive mechanism is coupled to the proximal end of the plunger rod and is configured to deliver a drive force FD to move the plunger rod from the first position to the second position. A ratio of the mass of the plunger rod to the drive force of the drive mechanism (MP/FD) is in a range of approximately a value greater than 0 kg/kgf to approximately 0.05 kg/kgf.

Abstract: A method for determining predicted failure rates of drug injection devices includes receiving a set of parameters that specify physical properties of (i) a syringe, and (ii) a liquid drug, and (iii) a drug injection device configured to deliver the liquid drug to a patient via the syringe. The method further includes receiving failure rate data that specifies a measured rate of failure of the drug injection device in response to various peak pressures within the syringe, applying the received set of parameters to a kinematic model of the drug injection device to determine a predicted peak pressure within the syringe, including determining the predicted peak pressure as a function of impact velocity of the liquid drug, determining a probability of failure of the drug injection device using (i) the received failure rate data and (ii) the predicted peak pressure, and providing an indication of the determined probability of failure to an output device.

Abstract: Components of drug delivery devices can experience large impact forces by a spring-loaded drive mechanism causing a drug reservoir of the delivery device to fracture. For an autoinjector having a reservoir, a plunger rod, a drive mechanism, and a carrier that experiences two impact events when the autoinjector is activated, the mass of the carrier and the mass of the rod is increased by a mass multiplier to reduce the impact pressure at both first and second impacts. The internal pressure of the device decreases in relation to a mass of the impact system 110 to force ratio, where the force is the drive force of the drive mechanism. To reduce the impact pressure from the first event, the mass of the plunger rod may be increased within a range such that the ratio of plunger rod mass to drive force is within a range of approximately a value greater than 0 kg/kgf to approximately 0.05 kg/kgf.

Abstract: A method for determining predicted failure rates of drug injection devices includes receiving a set of parameters that specify physical properties of (i) a syringe, and (ii) a liquid drug, and (iii) a drug injection device configured to deliver the liquid drug to a patient via the syringe. The method further includes receiving failure rate data that specifies a measured rate of failure of the drug injection device in response to various peak pressures within the syringe, applying the received set of parameters to a kinematic model of the drug injection device to determine a predicted peak pressure within the syringe, including determining the predicted peak pressure as a function of impact velocity of the liquid drug, determining a probability of failure of the drug injection device using (i) the received failure rate data and (ii) the predicted peak pressure, and providing an indication of the determined probability of failure to an output device.