Biocompatibility testing questions.
Is biological testing still required for medical devices?
The 2018 version of ISO 10993 emphasises risk assessment and chemical understanding. This means that if the combination of chemicals and materials in a device are known and their toxicity is known, this information can be combined to with knowledge of the product's use to eliminate biological testing when appropriate. It is still a good idea to conduct cytotoxicity testing and in some cases an investigation of local effects.
Is chemical extract testing required for medical devices?
ISO 10993 has chemical characterisation as the first requirement in the testing matrix. It encourages the use of this chemical analysis when insufficient information is available to define all the required toxicity end points. It is only required if the material review and risk assessment conclude that this information is not available.
How do I calculate sample requirements for medical device biocompatibility testing?
Part 12 of ISO 10993 details the ratio of extract solvent volume to device surface required to produce the test fluids. This ratio can be applied to devices and pharmaceutical containers. Your testing supplier will be able to advise you on what volume of fluid is required for each test. In the case materials characterisation, and leachables and extractables the required volume is often 50 to 100ml.
What is the testing biocompatibility matrix?
The biological evaluation matrix in ISO 10993 lists end points for toxicity assessment for medical devices. The end points required are defined according to the invasiveness of the device's use and its duration of contact. An end point is a toxicological risk that must be discussed and evaluated with the object of showing that the risk from a device is insignificant when compared to the benefit. Examples are cytotoxicty, geneotoxicity and mutagenicity.
Why is EMC testing required for my medical device?
Medical equipment must be immune to the influence of reasonable levels of interference from radiated or conducted emissions. That is to say, its performance should not be altered by emissions from equipment in the vicinity. Equally the device in question must not emit levels of interference that would influence other equipment. The syringe pump on bed B should not effect the pacemaker in bed A.
What is EMC testing?
All electrical and electronic equipment will emit some electromagnetic interference and could be effected by external radiation. Electromagnetic compatibility (EMC) testings measure emissions and resistance to interference both from radiation and conducted through wiring.
Extractables and leachables questions
What is extractables and leachables testing?
It is obviously undesirable for a medication or a medical device to introduce unwanted substances to the human body. E&L testing investigates substances (organic and inorganic) that probably will be and possibly could be released to a patient form medical devices, pharmaceutical production and pharmaceutical packaging. The aim is to identify and quantify chemical species to allow an informed toxicological risk assessment.
Extractables and leachables definition
Leachables are materials which are likely to migrate into drug products during storage or production. They can subsequently be identified in laboratory investigations.
Extractables could similarly find their way into medications but with a lower probability. They are identified in the laboratory using ‘forced’ extraction.
In the case of medical devices leachables are substances that are likely to be released to a patient during use. Extractables are materials that could be released in long term use or if the device is damaged.
Packaging validation questions
Which is the best transit simulation protocol to use for medical device packaging?
The 2019 edition of ISO 11607 lists ISTA 3A and ASTM D4169 as alternatives for transit validation. Both test regimes are intended for packages that can be handled in small parcel distribution. This is a worse case than pallet distribution and is normally the chosen direction.
What is transit simulation?
When sterile devices are distributed in the delivery chain there is significant risk of damage from vibration and impacts. Simulation is conducted to measure the effects of external impacts and internal product movement on the sterile barrier. After cartons have been subjected to atmospheric conditioning and the transport inputs, the blister or pouch packs inside are tested for seal strength and integrity.
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