The United States Food and Drug Administration (FDA) has established classifications for approximately 1,700 generic medical devices. Each generic device is assigned to a regulatory class based on the level of control necessary to assure the safety and effectiveness of the device. The three classes and the requirements which apply to them are:
Class I General Controls (With Exemptions; and Without Exemptions)
Class II General Controls and Special Controls (With Exemptions; and Without Exemptions)
Class III General Controls and Premarket Approval
The class to which a device is assigned determines the type of premarketing submission/application required for FDA clearance to market. A device classified as Class I or II, and not exempt, requires a 510k for marketing.
Class III devices generally require premarket approval application (PMA) is required unless a device is a preamendments device (on the market prior to the passage of the medical device amendments in 1976, or substantially equivalent to such a device) and PMA's have not been called for. In that case, a 510k will be the route to market.
Device classification depends on the intended use of the device and also upon indications for use. In addition, classification is based on the risk the device poses to the patient and/or the user. Class I includes devices with the lowest risk and Class III includes those with the greatest risk.
Materials Used In Medical Devices
The FDA may require biological evaluation of medical devices to determine the potential toxicity resulting from contact of the component materials of the device with the body. According to the FDA, the device materials should not, either directly or through the release of their material constituents:
(i) produce adverse local or systemic effects;
(ii) be carcinogenic;
(iii) produce adverse reproductive and developmental effects.
The appropriate tests for biological evaluation of a medical device is determined by the chemical characteristics of device materials and the nature, degree, frequency and duration of its exposure to the body. In general, the tests may include: acute, sub-chronic and chronic toxicity; irritation to skin, eyes and mucosal surfaces; sensitization; hemocompatibility; genotoxicity; carcinogenicity; and, effects on reproduction including developmental effects. Additional tests may be necessary for some devices.
The International Standards Organization (ISO) developed a standard for biological evaluation of medical devices (ISO 10993) to evaluate the effects of medical device materials on the body. This standard provides guidance for selecting the tests to evaluate the biological response to medical devices, and appropriate methods to conduct the biological tests.
(content from this page: www.fda.gov)