In vivo models to evaluate ingestible devices: Present status and current trends

Evaluation of orally ingestible devices is critical to optimize their performance early in development. Using animals as a pre-clinical tool can provide useful information on functionality, yet it is important to recognize that animal gastrointestinal physiology, pathophysiology and anatomy can differ to that in humans and that the most suitable species needs to be selected to inform the evaluation. There has been a move towards in vitro and in silico models rather than animal models in line with the 3Rs (Replacement, Reduction and Refinement) as well as the better control and reproducibility associated with these systems. However, there are still instances where animal models provide the greatest under-standing. This paper provides an overview of key aspects of human gastrointestinal anatomy and physiology and compares parameters to those reported in animal species. The value of each species can be determined based upon the parameter of interest from the ingested device when considering the use of pre-clinical animal testing. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

Evaluation of orally ingestible devices is crucial for optimizing performance, with animal models providing useful information but the selection of the most appropriate species being key due to differences in gastrointestinal physiology. There is a shift towards in vitro and in silico models over animal models for better control and reproducibility, while acknowledging that animal models still offer valuable insights in certain cases.