Development of an advanced injection time model for an autoinjector

Area of Science:

• Biomedical Engineering
• Pharmaceutical Technology

Background:

• Autoinjectors are critical for parenteral drug delivery.
• Accurate prediction of injection time is essential for autoinjector development and commercialization.

Purpose of the Study:

• To develop and validate an advanced physics-based mathematical model for predicting autoinjector injection time.
• To quantify the probability of achieving desired injection times.

Main Methods:

• Modeled injection time parameters as statistical variables with distribution functions.
• Employed Monte Carlo simulation to determine injection time probabilities.
• Conducted experimental validation with autoinjector testing.

Main Results:

• Demonstrated excellent agreement between modeled and measured injection times.
• Achieved modeling errors below 12% across various device configurations.
• Identified a slight model bias potentially due to internal friction.

Conclusions:

• The developed model is accurate, computationally inexpensive, and suitable for statistical simulations.
• The model effectively determines expected injection time ranges considering component variability.
• Validated approach supports robust autoinjector design and development.