Long-Term Stability of the Electronic Sensor Component of a Digital Pill System in Real-World Storage Settings

Abstract

Background: Digital pill systems comprise an ingestible sensor integrated into a gelatin capsule that overencapsulates medication allowing real-time measures of medication ingestion. These systems may improve the manner in which medication adherence can be assessed and supported. Objective: In this investigation, we tested the durability of the ingestible sensor as part of a clinical trial to measure the feasibility and acceptability of the system to measure adherence to once daily tenofovir disoproxil fumarate/emtricitabine (NCT03842436). Methods: Digital pills not dispensed during the study were stored in a pharmacy. Seventeen sensors were selected from digital pills stored for at least 12 months and activated in a simulated gastric environment. A radiofrequency spectrum analyzer and the reader device used in the clinical trial to capture ingestion events were used to measure activation of emitters. A passing evaluation was defined as an energized emitter within 30 minutes of immersion, ability to broadcast a signal for 10 minutes, and successful acquisition by the reader. Results: All ingestible sensors passed the stability test. Mean activation time in simulated gastric fluid was 3.33 minutes (SD = 1.47); emitters remained active for a mean of 47.72 minutes (SD = 1.78). These parameters matched guidelines defined in the ID-Cap system requirements for use in patients. Conclusions: Ingestible sensor components of the ID-Cap system were therefore stable after long-term storage.

The Case for Digital Pill Use in Clinical Trials

“…A digital signal transmits medication ingestion data in real time. 8,9 A wearable device picks up the signal and transmits the information for use by the clinician and researcher.…”

“…8 Digital pills have also shown long-term stability when stored in real-world conditions during long-term use. 9 Fifteen-years of experience and safety data support the use of digital pills, with over 140,000 ingestions recorded in more than 1,000 patients who have used these devices safely and effectively. 10 Digital pill systems have demonstrated a high rate of accuracy, with one study showing 99.4% adherence (2,807 ingestions detected/2,824 ingestions prescribed) in kidney transplant patients.…”