#FDA Tag

This guidance, published in March, is aimed at all those involved in the regulatory submission of medicinal product data. It supports the development and implementation of the International Organization for Standardization (ISO) Identification of Medicinal Products (IDMP) standards for substances, terminologies and other information used throughout the medicinal product development lifecycle worldwide.

The purpose of these standards is to make the international exchange of medicines information between stakeholders more accurate, complete, and consistent.

The five IDMP standards and corresponding technical specifications, were developed within the ISO network member organizations. The standards, originally published in 2012 by ISO, provide a framework (data models, terms, definitions, etc.) to uniquely identify and describe medicinal products with consistent documentation and terminologies to enable reliable exchange of product information between global regulators, manufacturers, suppliers, and distributors.

The FDA supports these standards for the identification and description of marketed non-investigational medicinal products, with the goal of harmonizing the standards for the international exchange of medicinal product data.

This guidance serves as a guidance document made available by the FDA and contains helpful but nonbinding recommendations.


FDA Guidance “Identification of Medicinal Products – Implementation and Use“.

The U.S. Food and Drug Administration (FDA) has updated (Revision 1) its Guidance for Industry on Out-of-Specification (OOS) Results. The first version of the document was dated October 2006.

The guide follows a step-by-step approach consisting of three main phases for investigating OOS test results


The process outlined in the text follows quite closely the requirements laid out in 21 CFR part 211.


The definition of “OOS” has not changed.

«the term “OOS results” includes all test results that fall outside the specifications or acceptance criteria established in drug applications, drug master files (DMFs), official compendia, or by the manufacturer.  The term also applies to all in-process laboratory tests that are outside of established specifications

Comparison with the 2006 version

The revision of the guideline contains some formal adjustments from the previous version, and also focuses on updating references to other FDA relevant guidelines and regulatory requirements (USP chapters, CFR paragraphs, etc.)

In addition, the new text contains some clarifications or rewordings from the 2006 edition, the following changes are worth mentioning:

  • section IV.C.2.: the wording on “Outlier Tests” has been amended as follows:
  • Version October 2006“Occasionally, an outlier test may be of some value in estimating the probability that the OOS result is discordant from a data set, and this information can be used in an auxiliary fashion, along with all other data from the investigation, to evaluate the significance of the result.”
  • Version May 2022“Occasionally, an outlier test may be of some value in understanding how discordant from a data set a result is, but can be used solely in an informational capacity in the course of an investigation to determine the distance of a result from the mean.”
  • Section V.B. – Cautions: has been divided into three subsections:
  1. Averaging results from multiple sample preparations from the original sample
  2. Averaging results from same final sample preparation
  3. Borderline results that are within specification

Both versions of the guideline can be downloaded from the FDA homepage.