Development and usability of a new subcutaneous auto-injector device to administer hydroxyprogesterone caproate to reduce the risk of recurrent preterm birth.

Background: Current administration of hydroxyprogesterone caproate (HPC) by intramuscular injection is associated with limitations, including the potential for human error and contamination, patient anxiety, and increased risk of needlestick injury.

Objective: To describe the design of an auto-injector for subcutaneous (SC) administration of HPC and the results of studies that evaluated the target user's understanding of the proper use of this device.

Materials And Methods: A single-use, prefilled, fixed-dose, disposable auto-injector intended for the SC administration of HPC was developed, and its usability by health care providers was evaluated in 3 formative (N=32, 64 injections) and 3 validation studies (N=45, 90 injections).