BS EN ISO 10993-5:2009

BS EN ISO 10993-5:2009 Biological evaluation of medical devices. Tests for in vitro cytotoxicity (ISO 10993-5:2009)

BS EN ISO 10993-5 has been revised and now contains informative annexes that identify the sections of the standard that conform to the Medical Devices Directives 93/42/EEC and 90/385/EEC, for medical devices and active implantable medical devices.

BS EN ISO 10993-1 is part of the ISO 10993 series that consists of the following parts, under the general title Biological evaluation of medical devices:

• Part 1: Evaluation and testing
• Part 2: Animal welfare requirements
• Part 3: Tests for genotoxicity, carcinogenicity and reproductive toxicity
• Part 4: Selection of tests for interactions with blood
• Part 5: Tests for in vitro cytotoxicity
• Part 6: Tests for local effects after implantation
• Part 7: Ethylene oxide sterilization residuals
• Part 9: Framework for identification and quantification of potential degradation products
• Part 10: Tests for irritation and delayed-type hypersensitivity
• Part 11: Tests for systemic toxicity
• Part 12: Sample preparation and reference materials
• Part 13: Identification and quantification of degradation products from polymeric medical devices
• Part 14: Identification and quantification of degradation products from ceramics
• Part 15: Identification and quantification of degradation products from metals and alloys
• Part 16: Toxicokinetic study design for degradation products and leachables
• Part 17: Establishment of allowable limits for leachable substances
• Part 18: Chemical characterization of materials
• Part 20 Principles and methods for immunotoxicology testing of medical devices

Due to the general applicability of in vitro cytotoxicity tests and their widespread use in evaluating a large range of devices and materials, it is the purpose of this part of ISO 10993, rather than to specify a single test, to define a scheme for testing which requires decisions to be made in a series of steps. This should lead to the selection of the most appropriate test.

Three categories of test are listed: extract test, direct contact test, indirect contact test.

The choice of one or more of these categories depends upon the nature of the sample to be evaluated, the potential site of use and the nature of the use.

This choice then determines the details of the preparation of the samples to be tested, the preparation of the cultured cells, and the way in which the cells are exposed to the samples or their extracts.

At the end of the exposure time, the evaluation of the presence and extent of the cytotoxic effect is undertaken.

It is the intention that BS EN ISO 10993-5 leaves open the choice of type of evaluation. Such a strategy makes available a battery of tests, which reflects the approach of many groups that advocate in vitro biological tests.

The numerous methods used and endpoints measured in cytotoxicity determination can be grouped into the following categories of evaluation:

• Assessments of cell damage by morphological means
• Measurements of cell damage
• Measurements of cell growth
• Measurements of specific aspects of cellular metabolism.

There are several means of producing results in each of these four categories. The investigator should be aware of the test categories and into which category a particular technique fits, in order that comparisons be able to be made with other results on similar devices or materials both at the intra- and interlaboratory level.

Examples of quantitative test protocols are given in annexes. Guidance for the interpretation of the results is also provided.

Contents of BS EN ISO 10993-5 include:

• Introduction
• Scope
• Normative references
• Terms and definitions
• Sample and control preparation
• Preparation of liquid extracts of material
• Preparation of material for direct-contact tests
• Preparation of controls
• Cell lines
• Culture medium
• Preparation of cell stock culture
• Test procedures
• Number of replicates
• Test on extracts
• Test by direct contact
• Test by indirect contact
• Determination of cytotoxicity
• Test report
• Assessment of results
• Neutral red uptake (NRU) cytotoxicity test
• Colony formation cytotoxicity test
• MTT cytotoxicity test
• XTT cytotoxicity test
• Bibliography

BS EN ISO 10993-5:2009 replaces BS EN ISO 10993-5:1999, which has been withdrawn.