This article covers topical issues in the regulation of medical devices in the US, including:

Medical devices are comprehensively regulated in the US by the Food and Drug Administration (FDA). The FDA regulatory scheme is both complex and constantly evolving. The device regulatory requirements apply only to those products that are considered "devices", although whether a product is a "device" under the Federal Food, Drug, and Cosmetic Act (FDC Act) is not always clear.

Under the FDC Act, product regulation is heavily influenced by product classification. A device is subject to very different requirements than a drug, and consumer products are not regulated by FDA at all. Therefore, to understand how a product will be regulated, it is important to understand how it will be classified.

Under the FDC Act, a device is defined as an article "intended for use in the diagnosis of disease or other conditions, or in the care, mitigation, treatment, or prevention of disease in a man" or "intended to affect the structure of any function of the body of man" (21 USC § 321(h)).

This definition places a heavy emphasis on "intended use". Intended use is determined by the objective intent of the manufacturer, such as claims in promotional materials or labelling (21 CFR § 801.4). It is not affected by how the product is actually used. While some products are inherently devices, such as pacemakers or glucose tests, manufacturers can often control how a product is regulated by controlling what they say.

In some cases, a product may be regulated as a device if the manufacturer makes one set of claims, and as a consumer product if the manufacturer makes other claims. This principle is well-established and enshrined in FDA's regulations. For example, scales to measure weight are devices if intended for clinical purposes. Otherwise, they are consumer products, and regulated under a different, much less rigorous law.

Another example involves Personal Sound Amplification Products (PSAPs). Because these are intended simply to amplify sounds (such as helping hunters hear prey or amplify the sound from television sets) and do not make any medical claims, they are regulated as consumer products. In contrast, products that are intended to address hearing loss are considered hearing aids, and are regulated by FDA as devices.

Drawing the line between these two categories is not easy. FDA initially released a guidance document that was designed to differentiate PSAPs from hearing aids. In response to aggressive marketing materials by PSAP companies, FDA proposed a new, more restrictive guidance document in 2013. More recently, and in response to arguments that PSAPs should be promoted to individuals with hearing loss, FDA has reopened the comment period on its draft guidance document. This controversy vividly demonstrates a recurring issue, that defining the line between a device and a consumer product can often be very challenging. Section 513(g) of the FDA Act does establish a mechanism by which companies can ask FDA whether a product is a device.

There is also a second type of jurisdictional issue that occurs regularly, whether the product be regulated as a device or a drug (or biologic). That issue can take two forms. The first is whether the product itself is a drug or a device. The second variant involves how to regulate products which combine device and drug components.

The first question arises because the definition of a device and drug are very similar. However, there is an exclusionary clause in the device definition, so that it includes only a product "which does not achieve its primary intended purposes through chemical action within or on the body of man or other animals and which is not dependent upon being metabolized for the achievement of its primary intended purposes."

That definition naturally raises a series of questions. What, exactly, does "achieve" mean? In other words, how much of the impact must be attributed to the drug action before the "achieve" threshold is reached? Similarly, what is "chemical action"? Many actions which are generally thought of as "physical" may have a "chemical" action when considered at the molecular level. What criteria are used to determine whether an intended use is "dependent" on metabolisation?

As for the second issue, FDA will determine whether the product will be reviewed as a device or drug based on "the primary mode of action of the combination product". That definition, too, is prone to questions. One of the most important issues is how to decide which of the two modes of action, physical or chemical, is primary.

Product classification decisions can be crucial to the fate of a product. While both devices and drugs are regulated by FDA, the manner of regulation differs materially. In general, devices face an easier pathway to the market. In many cases, a product will be commercially viable only if it will be regulated as a device.

Most often, it will be clear whether a product will be regulated as a device or as a drug. However, product jurisdiction can be uncertain for an increasing number of products, particularly with the rapid growth of products that combine drug and device components.

FDA has established a mechanism to learn the regulatory classification of the product at an early stage. Called the "Request for Designation" (RFD), this submission enables an applicant to find out how FDA will regulate its product. An RFD is submitted to FDA's Office of Combination Products (OCP). OCP then has 60 days in which to issue its decision. The RFD must contain, among other elements, a description of the product, the sponsor's recommendation for how the product should be regulated, and data supporting the sponsor's recommendation. OCP will respond within 60 days, as otherwise the sponsor's recommendation would take effect.

Companies seeking device status must think carefully about how they craft their RFD. Applications are limited to only 15 pages, and yet must contain sufficient data to show why the primary mode of action of a combination product is that of a device, or why any chemical action is not necessary to "achieve" the intended purpose(s) of the product. Companies seeking device classification must be careful to avoid using any language which inadvertently supports drug status. Although the applicable law is phrased neutrally, OCP has exhibited a strong preference for drug status. In effect, the burden is on the applicant to prove why the product should be regulated as a device.

Applicants should also be aware that OCP does not consider itself bound by precedents. Unless the product is exactly the same as another product and has the identical intended use, OCP appears to consider itself free to undertake a new examination of the product's appropriate jurisdiction. The US Congress is considering legislation to address some of the problems that have arisen with the product jurisdiction process. FDA also created a Combination Products Policy Council to address some jurisdictional and designation issues and practices.

OCP does allow companies to submit an "informal RFD". This is a submission where the company forwards its data and arguments in advance of making a formal application. OCP's response is non-binding. However, this response will give the manufacturer a clear indication of OCP's thinking, and may allow the company to adjust the formal RFD in light of OCP's feedback.

Product jurisdictional issues routinely arise. While in many instances a product is unquestionably a device, in some instances it will not be clear whether a product is, on the one hand, a device or a consumer product, or, on the other hand, a device or drug. In either case, product classification profoundly affects regulatory obligations. Manufacturers need to be alert to these issues and address them carefully.

Many devices require FDA review before they can be marketed. The primary means (roughly 98% of FDA reviewed devices) are through 510(k) pre-market notifications. However, after a company achieves 510(k) clearance for a medical device, the product rarely remains static. Opportunities for cost savings, obsolescence of parts or changes in suppliers, competitive pressures, product performance issues, and changes in standards and laws, can result in design and material changes. The levels of performance may not match the company's goals or commercial needs, and companies may want to include upgrades in new production. Customer-driven changes in features or revised marketing campaigns may affect product claims.

Companies should not simply make these changes. Before such changes are implemented, a 510(k) modification analysis is necessary to determine whether a new 510(k) submission and clearance is required to distribute the modified product.

Device manufacturers need to promote their products. FDA extensively regulates promotional activities, and has restricted the dissemination of information about off-label uses. Those restrictions are under assault by companies invoking the First Amendment of the US Constitution, which protects free speech.

One of the most controversial device regulatory issues is whether FDA should regulate Laboratory Developed Tests (LDTs). For several decades, FDA has asserted that it has the authority to regulate LDTs (sometimes also referred to as "home brew assays"). However, it is only recently that FDA has taken steps to begin doing so. In October 2014, FDA issued draft guidance documents outlining its planned regulatory framework for LDTs. Since their issuance, there has been much debate about FDA's authority to regulate LDTs (including whether FDA can do so through guidance rather than formal notice and comment rule making) and the effect of such regulation on the lab industry and patient care. Several legislative counter proposals have been put forth. If FDA's efforts become a reality, it will mean major changes in laboratory operations, and constitute one of FDA's most important regulatory initiatives of the past decade. Although the exact number of LDTs is unknown, there are certainly tens of thousands of LDTs in the US. FDA has stated that it plans to issue final LDT guidances before the end of 2016.