ABS Corporation

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July 23, 2026

CMS Case: 732115

WARNING LETTER

Dear Mr. Wood:

The United States Food and Drug Administration (FDA) inspected your drug manufacturing facility, ABS Corporation, located at 7031 N 16th St. Omaha, Nebraska, from January 12th to 16th 2026.

This warning letter summarizes significant violations of FDA’s Current Good Manufacturing Practice (CGMP) regulations for finished pharmaceuticals. See Title 21 Code of Federal Regulations (CFR), parts 210 and 211 (21 CFR parts 210 and 211).

Because your methods, facilities, or controls for manufacturing, processing, packing, or holding do not conform to CGMP, your drug products are adulterated within the meaning of section 501(a)(2)(B) of the Federal Food, Drug, and Cosmetic Act (FD&C Act), 21 U.S.C. § 351(a)(2)(B).

Current Good Manufacturing Practice Violations

We reviewed your January 30, 2026, response to our Form FDA 483 in detail. We have not received any other correspondence from you regarding this inspection.

Our review of the evidence gathered during the inspection and your response revealed significant violations, including the following.

1. Your firm failed to thoroughly investigate any unexplained discrepancy or failure of a batch or any of its components to meet any of its specifications, whether or not the batch has already been distributed (21 CFR 211.192).

Your firm manufactures animal drugs for (b)(4) and (b)(4) use. Your firm released drug products with confirmed out of specification (OOS) results without performing corrective actions explicitly required by your approved Master Production Records (MPR).

For example, during the manufacture of (b)(4), your firm repeatedly failed to perform required (b)(4) adjustments and released batches with confirmed OOS (b)(4) results. For Lot (b)(4), finished product testing yielded an OOS (b)(4) result of 4.03 (specification: (b)(4)). During your corrective and preventative action (CAPA) investigation, internal retesting of three individual bottles produced (b)(4) results of 4.49, 4.51, and 4.40 — the third result of 4.40 also failed to meet the established specification. Rather than invalidating the OOS result through a scientifically justified investigation, your firm (b)(4) the three results ((b)(4)), (b)(4) to (b)(4), and released the batch for distribution on July 21, 2025. Your investigation identified that the root cause was an in- process OOS result for (b)(4) and that the required corrective (b)(4) adjustment using (b)(4), as specified in your approved MPR, had not been performed.

Similarly, for Lot (b)(4), your firm obtained an in-process (b)(4) result of 4.0 (specification: (b)(4)). Again, production personnel failed to perform the corrective (b)(4) adjustment using (b)(4) as specified in your approved MPR. Your contract laboratory subsequently confirmed the finished product (b)(4) OOS at 4.06. Despite this confirmed OOS result, your firm released the batch for distribution on October 9, 2025.

Additionally, during (b)(4) validation of (b)(4) Tablets - (b)(4), Lot (b)(4), 17 out of (b)(4) in-process samples yielded assay results above the product USP specification of (b)(4) mg/tablet (b)(4) ((b)(4) mg/tablet) listed on your batch record. You manually changed the assay upper specification limit in the batch record from (b)(4) mg/tablet to (b)(4) mg/tablet by crossing out "(b)(4)" and handwriting "(b)(4)" with the initials of the person making the change and date (3/27/24), You did not document or provide a justification for this specification change.

Furthermore, you failed to investigate an in-process sample assay result of 346.90 mg/tablet, which exceeded the revised assay upper specification limit of (b)(4) mg/tablet. Despite exceedances of both the original USP specification and the revised upper specification limit, during in-process testing, (b)(4) Tablets - (b)(4), Lot (b)(4) was sold in March 2024. The Certificate of Analysis for the finished product Lot reported an assay (b)(4) of 333.09 mg/tablet.

Adequate corrective actions and thorough investigations into a batch failure to meet established specifications are fundamental to ensure your products meet the established quality standards. Your specifications exist to ensure product safety, efficacy, and quality. Deviating from these specifications without scientific justification places animals receiving these products at risk.

Your response acknowledges the inappropriate use of (b)(4) analytical results to override individual OOS findings and the failure to perform corrective (b)(4) adjustments as required by your Master Production Record. You indicated that immediate corrections were implemented during the FDA inspection, including discontinuing the acceptance of averaged analytical results across all drug products and formally closing corrective and preventive action records which addressed (b)(4) OOS events. You committed to revising OOS and deviation investigation procedures to explicitly prohibit (b)(4), or (b)(4) of analytical results for batch disposition decisions, require documented scientific justification and predefined acceptance criteria for any retesting, and mandate Quality Assurance approval for all batch disposition decisions involving OOS results.

For the validation batch you acknowledged the failure to initiate an OOS investigation for an individual out-of-specification assay result and committed to revising validation procedures to require evaluation of individual assay results, define acceptance criteria for intra-batch and inter-batch variability, and use statistical tools to assess process variability.

Your response is inadequate because it fails to address the safety and disposition of distributed products. Specifically, the response provides no scientific justification or data to support the claim that OOS does not impact product quality and stability and fails to address the product distributed after a validation that included an OOS assay result and unjustified specification change.

The response also lacks commitment to retrospective safety assessment of distributed products and provides no specific timelines for procedure revisions or implementation.

In response to this letter, provide:

• A comprehensive, independent assessment of your overall system for investigating deviations, discrepancies, complaints, OOS results, and failures. Provide a detailed action plan to remediate this system. Your action plan should include, but not be limited to, significant improvements in investigation competencies, scope determination, root cause evaluation, CAPA effectiveness, quality unit (QU) oversight, and written procedures. Address how your firm will ensure that all phases of investigations are appropriately conducted.
• An independent assessment and remediation plan for your CAPA program. Provide a report that evaluates whether the program includes effective root cause analysis, ensures CAPA effectiveness, analyzes investigation trends, improves the CAPA program when needed, implements final QU decisions, and is fully supported by executive management.

2. Your firm failed to test samples of each component for identity and conformity with all appropriate written specifications for purity, strength, and quality. Additionally, your firm failed to withhold components from use until sampling, testing, examination, and release by the quality control unit (21 CFR 211.84(d) and 21 CFR 211.84(a)).

You failed to perform adequate identity testing on each shipment and lot of incoming components at high risk of contamination. Additionally, you used expired raw material in the manufacture of drug products before receiving retest results and subsequently released those batches for distribution after the material failed retesting. For example:

• Your firm’s raw material examination reports for (b)(4) lots identified by “(b)(4)” (b)(4) and (b)(4) used to manufacture (b)(4), Lot (b)(4), exp. (b)(4), (b)(4), Lot (b)(4), exp. (b)(4) and (b)(4), exp. (b)(4) lacked data for identity, (b)(4), and (b)(4) limits. Further, your firm manufactures (b)(4) products containing (b)(4), including (b)(4) (Lot (b)(4) and others). Your Quality Manager confirmed that your firm has not tested any received (b)(4) for the limit of (b)(4).
• Your firm used (b)(4) (item number (b)(4), (b)(4)) in the manufacture of Lot (b)(4) and Lot (b)(4), expiration date (b)(4), of (b)(4) despite the material having passed its retest date of April 25, 2024. On June 11, 2024, your contract laboratory reported that the material failed retesting. However, your firm released both batches for distribution on the same day you received the failing retest results (June 11, 2024). Your decision was based on a qualitative comparison of the Fourier-transform infrared (FT-IR) spectroscopy scan for OOS raw material and a previous scan spectrum of itself, that determined the material passed specification.

Without adequate testing, you do not have scientific evidence that your raw materials conform to the appropriate specifications before their use in the manufacture of your drug products. Your failure to adequately test high-risk components including (b)(4) and (b)(4) before use in drug manufacturing could result in adverse effects and represent considerable safety risk to animals receiving the drug products using these components.

As a manufacturer, you are responsible for sampling, testing, and examining drug components before their use in production to ensure adequate quality and to mitigate contamination risks.

Your response acknowledged inadequate sampling and testing controls and recognized that (b)(4) and (b)(4) are high-risk components requiring appropriate testing. You indicated that immediate corrections were implemented, including a requirement that each container of (b)(4) received for use in ingested drug products undergo (b)(4) and (b)(4) limit testing prior to release for manufacturing use, and each lot of (b)(4) received for use in drug product manufacturing undergo (b)(4) limit testing prior to release.

You committed to revising raw material sampling and testing procedures, updating incoming inspection and quarantine procedures and providing targeted training to Quality Control and Quality Assurance personnel on the revised procedures. Further, you committed to verify compliance with the new established procedures through routine receiving and batch record review, and trending of high-risk component testing to confirm compliance.

Regarding the use of components beyond its re-test date and releasing drug products that were manufactured using out of specification components, your response did not specifically address this deviation.

Your response is inadequate. While you committed to implement proper testing going forward, you failed to address the already distributed products that were manufactured with inadequately tested components. The response does not address the testing status or disposition of (b)(4) and (b)(4) containers currently in inventory that were received prior to implementation of the new testing requirements and provides no commitment to test retained samples from distributed product batches. You provided no risk assessment evaluating the probability of contamination in untested material and failed to commit or conduct a comprehensive retrospective review identifying all batches manufactured with inadequately tested material. Additionally, your response lacks specific timelines for procedure revisions, training completion, and full implementation of testing requirements.

In response to this letter, provide:

• A comprehensive, independent review of your material system, including but not limited to:
  o evaluating all suppliers of materials (components, containers, and closures) to determine if they are reliable and appropriately qualified;
  o an assessment of all materials to determine whether they are consistently of acceptable quality;
  o a review to ensure assigned expiration or retest dates are appropriate (supported by data);
  o adequacy of the supplier qualification program, and its selection, qualification, and disqualification provisions.
• Based on a thorough review, provide a summary of your systems corrective action and preventive action (CAPA) to remediate the supplier qualification program and prevent use of unsuitable components, containers and closures.
• The chemical and microbiological quality control specifications you use to test and release each incoming lot of components for use in manufacturing.
• A description of how you will test each component lot for conformity with all appropriate specifications for identity, strength, quality, and purity. If you intend to accept any results from your suppliers’ COAs instead of testing each component lot for strength, quality, and purity, specify how you will robustly establish the reliability of your supplier’s results through initial validation as well as periodic re-validation. In addition, include a commitment to always conduct at least one specific identity test for each incoming component lot.
• A summary of results obtained from testing all components to evaluate the reliability of the COA from each component manufacturer. Include your SOP that describes this COA validation program.
• A summary of your program for qualifying and overseeing contract facilities that test the drug products you manufacture.
• The firm name, address, and supplier qualification report, for your third-party laboratory or laboratories conducting your raw material testing.

3. Your firm failed to establish adequate written procedures for production and process control designed to assure that the drug products you manufacture have the identity, strength, quality, and purity they purport or are represented to possess (21 CFR 211.100(a)).

Your Quality Manager confirmed with the investigator that your firm does not write validation protocols, stating that "all equipment, steps, and acceptance criteria are listed within the batch record." The quality manager further confirmed to the investigator that your firm does not write final validation reports after process validation.

Our review of your (b)(4) Tablets - (b)(4) validation lot (b)(4) batch record found multiple deficiencies. The document evidenced product failure to meet quality attributes in-process specifications, incomplete in-process monitoring data with unexplained gaps and missing process parameters for key manufacturing equipment. Together, these deficiencies prevent an adequate assessment of process consistency and control and provide no evidence to establish validated operating ranges or to ensure process reproducibility.

Further, significant variability in critical quality attributes was neither investigated nor evaluated or changes documented and justified. When results exceeded established specification limits, your firm changed the specifications during validation to accommodate failing results rather than investigating and correcting the underlying process deficiencies.

Despite these deficiencies, you released the referenced validation batch and subsequently distributed multiple batches of (b)(4) Tablets - (b)(4) without adequate evidence that your manufacturing process is validated, controlled, or capable of consistently producing tablets that meet quality standards.

Process validation evaluates the design integrity and state of control of a manufacturing process throughout its lifecycle. Each significant manufacturing stage must be appropriately designed to ensure the quality of inputs, in-process materials, and finished products. Process qualification studies establish whether an initial state of control has been achieved and must be successfully completed before commercial distribution. Ongoing monitoring of process performance and product quality is then required to maintain a stable manufacturing operation over the product lifecycle.

Your response acknowledges deficiencies in process validation and change control and commits to revising your Validation Master Plan, updating validation protocol and report templates to include identification of critical quality attributes and critical process parameters with predefined acceptance criteria, and revising change control procedures to require documented assessment of validation impact and training requirements.

The response is inadequate because it fails to address the validation status and safety of products already distributed to the market. You provide no commitment to revalidating existing processes using scientifically sound protocols with proper evaluation, no assessment of whether your currently marketed products were manufactured by processes in a state of control, and no scientific justification for the specification changes implemented, including toxicological assessment or stability data supporting the increased API concentration.

Your response also lacks specific timelines for completing procedure revisions, implementing new validation requirements, conducting revalidation studies, and training personnel. You state only that actions are "being revised" or "pending final approval" without providing commitment dates.

In response to this letter, provide:

• A detailed summary of your validation program for ensuring a state of control throughout the product lifecycle, along with associated procedures. Describe your program for process performance qualification and ongoing monitoring of both intra-batch and inter-batch variation to ensure a continuing state of control.
• A timeline for performing process performance qualification for each of your marketed drug products.
• Process performance protocol(s), and written procedures for qualification of equipment and facilities.
• A detailed program for designing, validating, maintaining, controlling and monitoring each of your manufacturing processes that includes vigilant monitoring of intra-batch and inter-batch variation to ensure an ongoing state of control. Also, include your program for qualification of your equipment and facility.

CGMP Consultant Recommended

Based upon the nature of the violations we identified at your firm, you should engage a consultant qualified as set forth in 21 CFR 211.34 to evaluate your operations and to assist your firm in meeting CGMP requirements. The qualified consultant should also perform a comprehensive six-system audit¹ of your entire operation for CGMP compliance and evaluate the completion and efficacy of your corrective actions and preventive actions before you pursue resolution of your firm’s compliance status with FDA.

Your use of a consultant does not relieve your firm’s obligation to comply with CGMP. Your firm’s executive management remains responsible for resolving all deficiencies and systemic flaws to ensure ongoing CGMP compliance.

Conclusion

The violations cited in this letter are not intended to be an all-inclusive list of violations that exist at your facility. You are responsible for investigating and determining the causes of any violations and for preventing their recurrence or the occurrence of other violations.

You must correct any violations promptly. Failure to promptly and adequately address this matter may result in regulatory or legal action without further notice, including, without limitation, seizure and injunction. Unresolved violations may also prevent other Federal agencies from awarding contracts.

FDA may withhold approval of new applications or supplements listing your firm as a drug manufacturer until any violations are completely addressed and we confirm your compliance with CGMP. We may re-inspect to verify that you have completed corrective actions to any violations.

This letter notifies you of our findings and provides you with an opportunity to address the above deficiencies. After you receive this letter, respond to this office in writing within 15 working days. Specify what you have done to address any violations and to prevent their recurrence. In response to this letter, you may provide additional information for our consideration as we continue to assess your activities and practices. If you cannot complete corrective actions within 15 working days, state your reasons for delay and your schedule for completion.

Send your electronic reply to CVM-483-Responses@fda.hhs.gov. Refer to the CMS Case number 732115 FEI 1950042 and ATTN: Dayna I. Martínez when replying.

Sincerely,
/S/

Johnetta Walters, Ph.D.
Acting Director
Division of Drug Compliance
Office Surveillance and Compliance
Center for Veterinary Medicine

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1 Including Quality System, Facilities & Equipment System, Materials System, Production System, Packaging & Labeling System, and Laboratory Control System as described in FDA’s guidance document Quality Systems Approach to Pharmaceutical CGMP Regulations.