NDA system

Of ultimate importance are the full reports of the clinical studies in humans and their results. These data will be treated statistically for their validity. The number of studies for a specific compound or combination of compounds will vary with the type of drug being tested, as will the number of tests needed to appraise relative or absolute safety and to clearly demonstrate efficacy. The basic requirement is the proof of safety and efficacy of the product being submitted under the NDA system. A drug that does not contribute to therapy, such as a new antihistamine that does not demonstrate greater safety or efficacy, or both, compared with drugs already on the market, will have a difficult or impossible time achieving approval. 

There have been hundreds of investigations and reports on the IND/NDA system. Numerous analyses have been done of the costs and benefits, and hundreds of recommendations have been made about ways to improve the system. Feelings run deep on these subjects, and the philosophical and emotional element often dwarfs the factual and analytical element. 

This brief survey of the FDA regulation of pharmaceutical products demonstrates the breadth and depth of FDA activity in this field. Although there are repeated calls for reform of the IND/NDA system, it appears unlikely that any substantial change will occur in the near future. It is therefore important that any person who enters the prescription drug industry in the United States be fully informed about the requirements, understand the regulatory risks involved, and comply adequately with all of the FDA requirements. 

The hardware and software of an NDA system depend on the specific conditions (e.g., environment, sample matrix, etc.) of the measurement task. In most cases, different NDA instruments are required to obtain the total quantity for a given nuclear material sample. Only a combination of the results of several calibrated NDA techniques provides for a credible assessment of the type and quantity of nuclear material. 

Modern nuclear facilities are increasingly automated with the aim of decreasing both personnel exposure and production costs. Owing to automation, direct access to nuclear material maybe limited for both the operator and the inspectorate. Unattended NDA systems generate measurement data without requiring the presence of an inspector. The data acquired are routinely collected from measurement cabinets after a certain period or are transmitted remotely to an external location (such as an inspector s office). Main attributes of various unattended NDA systems are listed in Table 63.6. 

The main drawback of these automated systems is their predictability. In most safeguards approaches, this drawback is compensated for by unannounced or short-notice inspections on a random basis. Most unattended NDA systems are part of the HLNC family. Other systems use low-resolution gamma detectors either in combination or as a stand-alone application. 

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