Chapter 3 - Irritation test

Abstract

Assessment of skin irritation is an integral component of the biocompatibility and biosafety evaluation of medical devices. For the safety evaluation of medical devices, various toxicological endpoints are described in EN/ISO 10993 series of standards. The endpoints considered for testing in medical devices depend upon device type, device contact with patient, and duration of contact. However, testing the skin irritation potential is recommended for almost all devices or its extracts. The International Organization of Standardization (ISO) 10993-10: Tests for irritation and skin sensitization describe the guidelines to evaluate potential irritation effects in the finished product. Historically, the rabbit (in vivo) skin irritation test is the most preferred irritation tests for evaluating safety of medical devices. Upon validation and regulatory acceptance, in vitro reconstructed human epidermis (RhE)-based test methods has become the regulatory standard for skin irritation testing. A recent study has demonstrated that the RhE-based test method produces results equivalent to those from the intracutaneous rabbit skin irritation test. These findings drove the creation of a new international standard, ISO 10993-23:2021 Biological evaluation of medical devices–Part 23: Tests for irritation. This standard specifies the guidelines for RhE-based in vitro testing models that shall be conducted to assess skin irritation before any in vivo animal testing is considered.