FDA’s Abbreviated New Drug Application Process Explained: How Generic Drugs Get Approved

When you pick up a prescription at the pharmacy, there’s a 90% chance it’s a generic drug. But how does that pill, tablet, or injection get approved to be sold at a fraction of the brand-name price? The answer lies in the FDA’s Abbreviated New Drug Application (ANDA) process - a system designed to bring safe, effective, and affordable generic medicines to market without repeating every clinical trial ever done.

What Is the ANDA Process?

The ANDA is the legal pathway for generic drug companies to get FDA approval. It’s called “abbreviated” because it doesn’t require the same mountain of clinical data as a brand-new drug. Instead, it builds on the FDA’s previous approval of the original drug - known as the Reference Listed Drug (RLD). If the brand-name drug was approved in 2010 and its patent expired in 2020, a generic maker can submit an ANDA to prove their version works the same way.

The whole system was created by the Hatch-Waxman Act of 1984. Before that, generic drugs faced long delays and legal battles. The law gave manufacturers a clear route to market while still protecting innovators’ patents. Today, it’s the backbone of America’s affordable drug supply.

How the ANDA Process Works

Getting an ANDA approved isn’t quick or easy, but it’s predictable. Here’s how it breaks down:

1. Submission: The company files electronically using the FDA’s Electronic Submission Gateway. They include Form FDA-356h (the application) and Form FDA-3674 (financial disclosures).
2. Filing Review: Within 60 days, the FDA checks if the application is complete. If it’s missing key data - like bioequivalence results or manufacturing details - it gets sent back.
3. Discipline Reviews: Teams of scientists review different parts: chemistry, manufacturing, labeling, microbiology, and bioequivalence. Each team looks for one thing: Is this generic exactly the same as the brand?
4. Information Requests: If something’s unclear, the FDA sends an Information Request (IR). This is where most delays happen. Companies often get 10 to 20 IRs before approval.
5. Approval or Tentative Approval: If everything checks out and there are no patent or exclusivity blocks, the FDA gives Final Approval. If there’s a patent still in effect, they issue Tentative Approval - meaning the drug is ready to go as soon as the patent expires.

The FDA’s goal under GDUFA III (the current user fee program) is to review 90% of original ANDAs within 10 months. But in reality, the average timeline is about 30 months. Why? Because complex products - like inhalers, creams, or injectables - take longer to prove equivalence.

What Makes a Generic Drug “Equivalent”?

The FDA doesn’t just say, “It looks the same.” They demand proof. For a generic to be approved, it must match the brand in five key ways:

• Active ingredient: Same chemical compound, same amount.
• Strength: Same dosage per pill or milliliter.
• Form: Tablet, capsule, liquid, injection - identical.
• Route of administration: Taken by mouth, injected, inhaled - same method.
• Labeling: Same warnings, directions, and uses - with minor exceptions.

The biggest hurdle? Bioequivalence. The generic must deliver the same amount of active ingredient into the bloodstream at the same rate as the brand. For simple pills, this is usually proven with one small study in healthy volunteers. But for complex products - like topical creams or nasal sprays - the FDA requires multiple studies, sometimes over years.

Why Is the ANDA Process So Important?

In 2023, generic drugs saved the U.S. healthcare system $373 billion. That’s not a guess. It’s from the FDA and IQVIA. Generics make up 90% of prescriptions but only 23% of drug spending. That’s because a brand-name drug might cost $500 a month - the generic version? $20.

This isn’t just about savings. It’s about access. Without the ANDA process, millions of people couldn’t afford their medications. Diabetics, heart patients, people with mental health conditions - they rely on generics to stay on treatment.

The FDA’s Office of Generic Drugs (OGD) approved over 1,100 ANDAs in 2022, with a 91% first-cycle approval rate. That’s a high success rate - but only for those who do it right.

Challenges Generic Companies Face

Even with a clear process, companies run into roadblocks:

• Complex generics: Products like inhalers, patches, or injectables are harder to copy. Bioequivalence studies cost $1 million or more per attempt.
• Patent thickets: Brand companies sometimes file dozens of minor patents to delay generics. This can push approval back for years.
• Facility inspections: The FDA must inspect every manufacturing site. If a plant in India or China fails inspection, the ANDA stalls.
• Information Requests: 78% of applicants report getting unexpected IRs. One company got 17 IRs on their first ANDA - delaying approval by 14 months.

The most common reasons for rejection? Inadequate bioequivalence studies (35%), manufacturing issues (28%), and labeling errors (22%).

Who’s Winning in the Generic Market?

The U.S. generic market was worth $127.6 billion in 2022 and is expected to hit $189.2 billion by 2027. A few big players dominate:

• Teva Pharmaceuticals: Holds 22% of the market. They’ve filed over 1,000 ANDAs.
• Viatris (formerly Mylan): 15% market share.
• Sandoz: 12% market share.

Most ANDAs come from companies that have already approved at least five generic drugs. These firms have teams of 10-15 people - regulatory affairs, pharmacists, chemists, QA/QC - working full-time on submissions. They spend 5,000 to 10,000 hours per ANDA.

How to Improve Your Chances of Approval

If you’re a generic manufacturer, here’s what works:

• Use pre-ANDA meetings: 78% of successful applicants meet with the FDA before submitting. It’s free. It saves time.
• Follow product-specific guidances: The FDA has over 2,000 of these. They tell you exactly how to test your product. Ignore them at your peril.
• Adopt Quality by Design (QbD): 68% of top manufacturers use QbD - building quality into the process, not just testing it at the end.
• Prepare for inspections: Don’t wait until the FDA shows up. Audit your own facility like they’re coming tomorrow.

Companies that treat the ANDA like a checklist get rejected. Those who treat it like a science project - with deep understanding, rigorous testing, and clear communication - get approved.

The Future of the ANDA Process

The FDA is changing. They’re focusing more on complex generics. In 2022, 35% of pending ANDAs were for tricky products like inhalers or topical gels. The agency is investing in new tools - like AI to analyze chemistry data - and real-world evidence to speed up reviews.

GDUFA III (effective 2022) pushes the FDA to meet tighter timelines. But the real challenge isn’t the process - it’s the barriers around it. Patent extensions, REMS restrictions, and supply chain issues still block access.

Still, the system works. It’s not perfect. But it’s the reason why your insulin, your blood pressure pill, your asthma inhaler costs a fraction of what it did 20 years ago.

What Comes Next?

If you’re a patient, you can trust generics. They’re safe, effective, and cheaper. If you’re a manufacturer, the ANDA process is tough - but it’s doable. The key is preparation, precision, and patience.

The system isn’t broken. It’s working - just slowly for some products. And that’s why the FDA is investing in AI, better guidances, and faster reviews. The goal? More generics, sooner. For everyone who needs them.