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CVM GFI #23 Medicated Free Choice Feeds--Manufacturing Control July 1985

Docket Number:
Issued by:
Guidance Issuing Office
Center for Veterinary Medicine

Revised 7/1/85


Liquid Feeds
Mineral Mixes



Free choice medicated feeds are those products which contain one or more animal drugs and are placed in feeding and grazing areas but are not intended to be fully consumed at a single feeding or to constitute the entire diet of the animal.

Free choice medicated feeds include such common feed products as medicated blocks, mineral mixes and liquid feeds. This document provides the necessary information for the manufacture of these type feed products under regulation 21 CFR 510.455 which provides for the new animal drug requirements.

Information concerning the manufacture of free-choice medicated products can be presented in a new animal drug application (NADA), in a supplement to an approved NADA or in a master file. If a master file is used to provide the information, proper reference to the source must be made in the NADA. Initial approval of the manufacture of the free-choice product must be made under an NADA submission. The manufacturing requirements are listed in 21 CFR 514.1(b)(5)(i) through (xiii).

Once initial approval has been granted under the NADA for the use of a free choice product, the product may be manufactured under a FDA-1800 application. The FDA-1800 application must provide for the information required under 21 CFR 510.455(e).


The manufacture of medicated free choice feed products is subject to the current good manufacturing practice regulations (cGMPs) for medicated feeds.. 21 CFR Part 225. The agency is aware that there are not specific GMP regulations for free choice products. The products because of their use are considered as a finished feed ready for consumption and thus fall under 21 CFR 255.

  1. Pre-Approval Requirements

    As a prerequisite for approval for use, the information listed in 21 CFR 514.1(b)(5) will be required. In addition, the sponsor will need to further address the following specific areas relative to the manufacture of free-choice type medicated products:

    • Raw Materials Controls
    • Analytical Controls
    • Stability
  2. Post-Approval Requirements

    Once approval has been given for the manufacture and use of a medicated free choice feed product, the manufacturer of the products will be regulated under the requirements of the cGMP regulations for medicated feeds as per 21CFR 225.

    The information below should be helpful in addressing the three subject areas.


    1. Active Ingredient:

      The source of the active ingredient(s) for a mediated free choice product may be an undiluted drug substance or a medicated premix. The source must be properly identified.

      (i)Bulk drug substance: If a bulk drug substance is to be used in preparing the product, the following information should be provided:

      IDENTIFICATION TEST: A test to determine that the chemical is what it purports to be. The test must be specific. This may be a simple chemical color test, an IR test, a TLC (Thin Layer Chromatography) test, etc.

      ASSAY TEST: A determinative (potency) test to assure the chemical has the potency it purports to have. The method itself (along with proper validation date, if necessary) or proper reference must be given.

      CERTIFICATE OF ANALYSIS: A certificate of analysis from the supplier may be used for the assay test. A copy should be submitted for review.

      The identification test must be conducted even when a certificate isavailable.

      (ii)Medicated Premix: If an approved medicated premix is used to prepare a free choice medicated product, the premix must be properly identified. If a copy of the certificate of analysis is available, it should be submitted for review.

    2. Inert Ingredients:

      Inert ingredients should meet AAFCO specifications, definitions, or other standards as applicable. References to the appropriate standard reference source(s) should be listed.


    1. Batch Analysis:

      Proper mixing should provide for a homogeneous dispersion of the active ingredient throughout the finished product. If the free-choice product is manufactured from a bulk drug substance or an approved medicated premix, duplicate samples from three (3) batches must be analyzed to assure proper quality control and manufacturing procedures are conducted. The data must be presented for review.

      Any site participating in the manufacture of the product will be expected to abide by the above analytical requirements.

    2. Release Specifications:

      Release specifications for each type of finished free choice feed product must be provided. The specifications should include the following:

      • Physical characteristics
      • Identification tests for the active ingredients(s).
      • Assay limits, including test methods for active ingredients(s).
      • Moisture determination, if applicable.

      The test methods used must be provided for review. References to official methods must be provided, if applicable. If unapproved methods are used, validation information must be provided. Validation should include accuracy, precision, and interference (specificity) data. Sampling procedures should be described.


    Because of the nature of the products and their proposed use, stability information is needed on the different types of free-choice feed products. Specific requirements for medicated blocks can be found in the Center for Veterinary Medicine Stability Guidelines. Requirements for liquid feeds should follow the guides listed under medicated premixes and finished feeds. Requirements for mineral mixes may be found under medicated premixes and finished feeds. The Guidelines also provide procedures on how to develop the needed stability data. Prior to initiation of a stability study, protocols for the stability program and study should be submitted to the Center for comment.


Submit Comments

You can submit online or written comments on any guidance at any time (see 21 CFR 10.115(g)(5))

If unable to submit comments online, please mail written comments to:

Dockets Management
Food and Drug Administration
5630 Fishers Lane, Rm 1061
Rockville, MD 20852

All written comments should be identified with this document's docket number: FDA-2021-D-0623.


Contact Point
Center for Veterinary Medicine
Food and Drug Administration
7500 Standish Pl, HFV-1
Rockville, MD 20855
(240) 402-7002
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