Seminar Report

Medical Plastics : Materials, Applications And Processing

For Medical Devices And Pharmaceuticals Industries

Genotoxicity

• These tests apply mammalian or non-mammalian cell culture techniques to determine 

• gene mutations 

• changes in chromosomal structure and number 

• other DNA or gene toxicities

          caused by the device, material or their extracts

Implantation

• Assesses the local pathological effects on the living tissue, at both the gross level and microscopic levels 

• Sample of the material or the device is surgically implanted in an appropriate site (muscle, dentin or bone) based on the intended application 

• Note : For a material, these tests are equivalent to sub chronic toxicity tests, if systemic effects are also investigated

Haemocompatibility

• Evaluates the effects on blood or blood components by blood contacting devices or materials 

• Specific haemocompatibility tests may have to be designed to simulate the 

• Geometry 

• contact conditions 

• flow dynamics  

          of the final application 

• Haemolysis tests determine the degree of blood cell lysis and release of hemoglobin caused by device / material samples

Chronic Toxicity 

• Estimates the effects of either single or multiple exposures, during the period of at least 10% of the life span of the animal model, to medical devices, materials or their extracts in suitable animal model 

Carcinogenicity

• These tests determine the tumorigenic potential of medical devices, materials or their extracts 

• The test duration shall cover a period over the major portion of the life span of the animal model 

• Can be carried out along with chronic toxicity studies 

• Note : Required to be conducted only if there are suggestive data from other sources 

Reproductive & Developmental Toxicity

• Studies the potential effects on 

• reproductive function 

• embryonic development (teratogenicity) 

• prenatal and early post natal development 

• Note : Need to be conducted only if the device has potential impact on the reproductive potential of the subject

Biodegradation

• Where the potential for resorption / degradation exists, these tests determine the 

• process of degradation 

• biotransformation 

• elimination of degradation products 

• Note : ISO 10993 is not very specific on the norms for selection of biodegradation studies; only the method is described

Basis for Selection of Tests 

• Categorization based on the nature of contact with human body

• Non contact devices 

• Surface contacting devices 

• External communicating devices 

• Implant devices

• Categorization based on the duration of contact

• Limited exposure devices (< 24 hours) 

• Prolonged exposure devices (multiple or long term exposure up to 30 days) 

• Permanent contact devices (contact exceeds 30 days)

Non contact devices

• Packaging materials 

• Medical instruments that does not come in contact with either the patient or the operator (Eg. Electrical components in a medical instrument) 

• No specific biological qualification is required except ensuring that these materials does not introduce leachants into the contacting products that could become harmful.

Surface contacting devices

• Skin : Devices that contact intact skin surfaces only  

• Electrodes, fixation tapes, compression bandages and various monitors 

• Mucosal membranes : Devices that contact intact mucosal membranes only 

• Endo tracheal tubes, contact lenses, bronchoscopes, intra uterine devices 

• Breached or compromised surfaces : Devices that contact breached or otherwise compromised body surfaces 

• Wound dressings, occlusive patches for ulcers, burns etc.