Toxicological Evaluation Of
Materials / Medical Devices

• diagnosis, prevention, monitoring, treatment or alleviation of disease
• diagnosis, monitoring, treatment, or alleviation of, or compensation for, an injury or handicap
• investigation, replacement or modification of the anatomy or of a physiological process control of conception. And theses medical device are fabricated with a single/multiple materials.

This covers a broad range of products including the products used everyday in most health care settings such as needles, syringes, infusion pumps, endoscopes, examination gloves, dressings and blood glucose meters. The ISO 10993-1 document divides medical devices into three main categories: surface devices, externally communicating devices and implant devices. Each category is further divided into subcategories according to the type of contact to which the patient is exposed.

Biological evaluation of medical devices depends on the materials used in the device, the intended body contact and the duration of contact. The objective of the biological evaluation of materials, intended for the fabrication of medical devices, is to investigate the potential biological hazards by careful observations for unexpected adverse reactions or events in humans during clinical use of the medical devices. The safety assessments of medical devices are guided by the toxicological and other studies recommended by the International Standard protocol. The ISO 10993 is concerned with the safety in use of medical devices and materials and is intended to assess the biological response of materials or devices as a part of the overall evaluation and development of devices.

Safety/toxicity evaluation of medical device assesses the risk of adverse health effects due to normal use and likely misuse of a device. Since adverse health effects could result from exposure to the materials from which a device is made, preclinical assessment of the toxic potential of such materials or components is needed to minimize the potential hazard to the patient. It was well aware that the medical device comprises several components made from different materials; the ideal procedure from a toxicological point of view would be, to test extracts of the components separately. However, in some situations this is not practical, and extracts of the whole device may be used instead. The amount of leachable substances released to the extraction media is related to the surface area and thickness of the product to be extracted. The range of potential biological hazards is wide and may include; Short term effects; like acute toxicity, irritation, sensitization, haemolysis and thromobogenicity. Long term effects; such as sub chronic and chronic toxicity, sensitization, genotoxicity, carcinogenicity and effects on reproduction including teratogenicity.

Due to the diversity of medical devices, it is recognized that not all the tests identified in a category will be necessary or practical for any given device. It is indispensable for testing that each device shall be considered on its own merits.

Dr. PV. Mohanan, Scientist & Head, Toxicology Division, Sree Chitra Tirunal Institute for Medical Sciences and Technology (Govt. of India), Biomedical Technology Wing, Poojapura, Thiruvananthapuram – 695012, Kerala.

Dr. Mohanan dis his PhD in ‘Toxicological / Safety evaluation of anticancer drug’ and Postdoctoral programme in toxicology at the Institute of Community Medicine, The University of Tsukuba, Japan.

He has 23 years experience in Pre-clinical toxicity / safety evaluation of medical devices, drugs, chemicals and tissue engineered products as per OECD, ASTM, USP, FDA, ISO protocols.

Dr. P.V. Mohanan, Scientist, Toxicology Division, Biomedical Technology Wing , Sree Chitra Tirunal Institute for Medical Sciences and Technology

He is a National GLP Inspector, participated in more than 23 GLP inspection in industry, Institute, CROs and Pharma companies both in India and abroad. Participated as a GLP Inspector during the Mutual Joint Visit by OECD GLP team, participated as an observer at the International GLP Inspection held at Switzerland and France. Faculty member at the training cum Refresher Course for GLP Inspectors and training course on Test facilities conducted by National GLP Compliance Monitoring Authority, Dept. of Science and Technology, New Delhi.

He has participated at the training on ‘Non-clinical safety testing of products’ organized by TDS of WHO (2005) and GLP Trainers trainee course (WHO, 2003) at New Delhi.

Presently, he is the Secretary-General of the Society of Toxicology India and General Assembly Councilor at the International Union of Toxicology, USA. He is a Fellow of Society of Toxicology, India, Fellow of Academy of Sciences for animal welfare,, recipient of prestigious JSPS award from Japan Society for the Promotion Sciences, Govt. Japan and STOX/ASAW – Surajben Jethalal Thaker Prakruti Mandir Gold medal award.

Dr. Mohanan is member of many professional bodies / societies related to Toxicology / Quality Assurance / Animal Welfare. He has 73 publications in National and International Journals and edited two books in GLP area.