Continuous manufacturing of drugs, and FDA's push to spread it

Three years after Congress set up a program to speed the use of new ways of making medicines, FDA's drug center had received five requests under it and granted none. As of October 16, 2025, the Center for Drug Evaluation and Research had turned down two requests and was still reviewing three, while FDA's biologics center had granted three designations out of 13 requests, according to the agency's first report to Congress on the Advanced Manufacturing Technologies Designation Program¹, published in December 2025.

Neither center had yet received a product application using a designated technology.

Continuous manufacturing is the technology FDA's early-engagement program has had the most success with, according to FDA's December 2025 strategy document on innovative manufacturing⁷. FDA argues that newer production methods can make supply more reliable and help prevent shortages. The same document says cost is a particular obstacle for generic makers, whose products often run into supply disruptions and shortages. This explainer covers how continuous production differs from batch production, the rules FDA has written since 2014, and what the record so far suggests for generic supply.

How continuous production differs from batch production

Traditional drug production runs in batches. Federal rules define a batch as "a specific quantity of a drug" made "according to a single manufacturing order during the same cycle of manufacture," under 21 CFR 210.3¹¹. Each step works on that fixed quantity, and material can sit between steps.

Continuous manufacturing links those steps. The ICH Q13 guidance⁵, which FDA adopted in March 2023, describes it as "the continuous feeding of input materials into, the transformation of in-process materials within, and the concomitant removal of output materials from a manufacturing process," and focuses on systems where two or more unit operations are directly connected. A 2022 paper by FDA scientists in the International Journal of Pharmaceutics⁸ summed it up as sending "materials directly and continuously to the next step of a process, eliminating hold times and reducing processing times."

Q13 allows several arrangements. Some steps can run in batch mode while others run continuously, every step can be continuous, or the active ingredient can be synthesized and turned into the finished product in one integrated line. A batch can be defined by run time, and a batch size can be set as a range with a minimum and maximum run time. One of the guidance's own examples describes a company validating a larger batch after approval by running longer, "without impact to the equipment scale."

Tracking material takes new methods. Q13 asks manufacturers to characterize residence time distribution, how long material takes to move through the system. That knowledge lets a plant trace a disturbance to the output it affected and divert that material. Our pieces on process validation and CGMP rules cover the quality framework these lines still sit inside.

What FDA has done since 2014

FDA's 2022 self-audit is the main public evidence on regulatory outcomes. Comparing continuous and batch applications, FDA staff found "no substantial regulatory barriers" for continuous applications on manufacturing changes or preapproval inspections. Continuous applicants reached approval 8 months faster at the mean and 3 months faster at the median, and reached market 12 or 4 months faster, which the authors estimated was worth $171 million to $537 million in earlier revenue.

A 2023 paper by FDA reviewers looked at the other side. Examining continuous and real-time release submissions for immediate-release tablets in new drug applications, it listed common deficiencies, including poor sampling strategies, inappropriate experimental designs and dissolution models that could not predict the full release profile, according to the paper in the Journal of Pharmaceutical Sciences⁹. Our explainer on dissolution testing explains what those models replace.

The designation program Congress created in 2022

Congress used the Food and Drug Omnibus Reform Act of 2022 to add section 506L to the Federal Food, Drug, and Cosmetic Act. Under FDA's final guidance³, a manufacturing method qualifies if it uses a novel technology, or an established one in a novel way, that will "substantially improve the manufacturing process for a drug while maintaining equivalent, or providing superior, drug quality." That can mean cutting development time or "increasing or maintaining the supply" of a drug that is life-supporting, life-sustaining, of critical importance to health care, or on FDA's shortage list.

The main benefit, FDA's guidance says, is early interaction, meaning timely advice and extra meetings or written exchanges with applicants using a designated technology, as resources permit. FDA says it will prioritize interactions on drugs made with a designated technology, with higher priority for those that could improve quality or keep a shortage-prone drug in supply. For ANDAs involving complex generics, those interactions would typically run through existing channels such as pre-ANDA meetings.

Source: FDA Report to Congress, Advanced Manufacturing Technologies Designation Program, CY 2025¹, data as of October 16, 2025.

CDER's two denials cited missing information on how the technology would cut development time or protect supply, no explanation of how it met the criteria for its intended use, and no showing that the method was novel. FDA's biologics center listed "unsubstantiated claims of manufacturing process or drug supply improvement" and "lack of novelty" among common reasons for denial.

The cost problem for generic makers

FDA's strategy document is direct about money. Adopting innovative manufacturing "entails a significant upfront investment," it says, and manufacturers "may not expect a sufficient long-term return." It adds that these considerations "are particularly important for generic manufacturers, which operate on smaller profit margins." Workshop panelists told FDA that legislation, guidance and financial incentives "could be particularly valuable for generic drugs that often experience supply chain disruptions, manufacturing and quality issues, and drug shortages." Our piece on the economics of making a generic covers those margins.

Regulation abroad is the other brake. Panelists said a lack of international harmonization leaves manufacturers unsure whether a process FDA accepts will clear other markets, the document says.

FDA's own shortage reporting makes the supply argument. Its report to Congress on 2024 drug shortages¹⁰ says advanced manufacturing can "improve drug manufacturing reliability" and "address shortages of medicines," and that it "may help domestic companies operate with lower costs and fewer quality manufacturing deviations in smaller facilities." Our explainers on why shortages happen and the onshoring push put that claim in context.

There is a mismatch in where the experience lies. The 2023 FDA review of continuous submissions covered oral immediate-release tablets, while 71 percent of the drugs on FDA's current shortage list on November 3, 2026, were injectables, according to GxRadar's analysis of FDA's shortage data¹³. Our shortage tracker has the full list, and our piece on sterile injectable shortages explains why those products dominate it.

Section 506L requires FDA to report to Congress every year, so the next count of requests and designations is due by late December 2026. Under the statute's sunset, FDA cannot consider new designation requests after October 1, 2032. FDA's advanced manufacturing page¹² collects the agency's guidance and funding notices in the meantime.