Re: US FDA Approved material list?
Does US FDA have a database for approved list of materials which can be used for medical device?
Not as such. However, US FDA does Recognize a number of material-related Standards, each of which defines a particular grade, composition or formulation of a material. See
http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/Standards/default.htm.
If you use such a material in your device, US FDA will accept that material as suitable from a formulation perspective, subject to any special conditions that the Standard defines. You may however have to show that your use of that material is suitable i.e. if the Standard recognizes uses A, B and C but your device uses the material in novel manner D, that will require evidence of suitability. See
http://www.fda.gov/MedicalDevices/D...sions/PremarketNotification510k/ucm142706.htm and
http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocuments/ucm077274.htm.
When a supplier claim their product is medical grade (eg, Polyethylene), what is US FDA definition of medical grade?
There is no such US FDA definition. Any material can be used in a medical device if it's safe and effective in the application.
Probably what the vendor means is either that the material conforms to a Standard that is Recognized by US FDA, or that the material has been subjected to an appropriate series of ISO 10993 biocompatibility tests by somebody--its maker, the vendor, or someone else--and found to be biocompatible.
In the former case, presumably the material willl be supported with a certification of conformance, plus perhaps some evidence such as a third party lab test. In the latter case, a statement of conformance is meaningless unless a copy of the third party lab test is provided as evidence that you can then provide to US FDA in conjunction with a clearance process for your device.
A warning: if you run into a material vendor that claims medical device suitability based on USP or "Class VI", watch out. FDA split medical device materials qualification from pharmaceutical-packaging materials qualification as of 1995. Anyone still using that system obviously hasn't paid any attention to materials qualification in at least sixteen years.