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. That’s not luck-it’s the result of a carefully designed regulatory system called the Abbreviated New Drug Application (ANDA). This process lets companies sell cheaper versions of brand-name medicines without repeating every single clinical trial. It’s how we get pills that work the same but cost a fraction of the price. And it’s been saving the U.S. healthcare system over $370 billion a year since the 1980s.

What Exactly Is an ANDA?

An ANDA is a shortcut. It’s not a full application like the one brand-name drugmakers use. Instead of proving a drug is safe and effective from scratch, generic companies prove their version is identical in performance to the original. The FDA already confirmed the brand-name drug works-so the generic maker just needs to show their version does the same thing in the body.

To qualify, the generic must match the brand in four key ways:

• Same active ingredient
• Same strength and dosage form (pill, injection, cream, etc.)
• Same way it’s taken (by mouth, injected, inhaled)
• Same intended use (what condition it treats)

It doesn’t need to look exactly the same-color, shape, or inactive ingredients can differ. But the active part? That has to be identical. And the body has to absorb it the same way.

How the ANDA Process Works

The ANDA process isn’t quick, but it’s structured. Here’s how it flows:

1. Submission: The company files electronically through the FDA’s Electronic Submission Gateway. They submit Form FDA-356h and a financial disclosure form. The filing team checks if everything’s there within 60 days.
2. Review: Teams of scientists-chemistry, manufacturing, microbiology, labeling, and bioequivalence experts-dig into the data. They check if the generic dissolves the same way, if the manufacturing plant meets standards, and if the labeling matches the brand’s (with minor exceptions).
3. Feedback: If something’s missing or unclear, the FDA sends an Information Request (IR). Most companies get at least one. Some get 10, 15, even 20. Each one adds months to the timeline.
4. Decision: If everything checks out, the FDA gives either Final Approval or Tentative Approval. Final Approval means the drug can be sold. Tentative Approval means the science is solid, but the brand still has patent or exclusivity protection. The generic can’t ship until that protection expires.

The FDA aims to review original ANDAs in 10 months under the GDUFA III rules that took effect in 2022. But in reality, the average time from submission to approval is about 30 months. Why? Delays in inspections, complex products, and back-and-forth requests add up.

Why the ANDA Process Saves Billions

Brand-name drugs cost an average of $2.3 billion to develop. That includes 10-15 years of research, clinical trials on thousands of patients, and marketing. Generic companies don’t do that. They focus on one thing: proving bioequivalence. That usually costs between $1 million and $5 million.

That’s why, within a year of a generic hitting the market, the price drops to about 15% of the brand’s cost. By 2023, generics made up 90% of all prescriptions filled in the U.S.-but only 23% of total drug spending. The savings? Over $370 billion in 2021 alone.

This isn’t just about money. It’s about access. A patient who can’t afford a $500 brand-name pill can often get the generic for $10. That’s the whole point.

Where the ANDA Process Gets Complicated

For simple pills-like metformin or lisinopril-the ANDA process works smoothly. But for complex products? It gets messy.

Topical creams, inhalers, injectables, and transdermal patches are harder to copy. Why? Because how the drug is delivered matters as much as what’s in it. A cream’s texture, a spray’s particle size, an injection’s pH-all affect how the drug behaves in the body.

That’s why 35% of Complete Response Letters from the FDA in 2022 cited problems with bioequivalence studies for complex generics. One company spent $1.2 million and three tries to get their topical cream approved. Another waited 14 months because of 17 information requests.

Patents and exclusivity rules also slow things down. Even if a generic is ready, it can’t launch until the brand’s patent expires or a legal challenge clears the way. Some companies use legal tactics to delay generics for years-something called “patent thickets.”

Who’s Winning in the Generic Market?

The generic drug market is dominated by a few big players. Teva Pharmaceuticals controls about 22% of the U.S. market. Viatris (formerly Mylan) has 15%, and Sandoz holds 12%. Together, these three account for nearly half of all generic sales.

But 75% of ANDAs come from companies that already have five or more approved generics. Experience matters. Teva’s regulatory head said after their tenth ANDA, they hit FDA timelines 92% of the time. Newer companies? They’re learning the hard way.

The FDA now offers over 2,000 product-specific guidances to help applicants. In 2022 alone, they published 450 new ones. These aren’t suggestions-they’re roadmaps. Skip them, and your application will likely get rejected.

What’s Next for Generic Drugs?

The FDA is pushing hard to improve the ANDA process. They’re using AI to speed up chemistry reviews-78% of reviewers now use AI tools to analyze data. They’re also exploring real-world evidence to support approval for complex generics, instead of always requiring new clinical trials.

The goal? Faster approvals for drugs that treat shortages or unmet needs. In 2022, the FDA approved 117 priority generics to address drug shortages. That’s a big shift. The agency now treats generic approvals like a public health tool, not just a regulatory box to check.

Still, challenges remain. Manufacturing inspections still take too long. Some facilities overseas are hard to access. And patent fights keep dragging on. But the system is evolving-and it’s working.

What This Means for Patients

You don’t need to understand the science behind an ANDA. But you should know this: when your doctor prescribes a generic, you’re getting the same medicine at a fraction of the cost. The FDA doesn’t approve generics lightly. They require proof-hard data-that it works just like the brand.

If your pharmacy gives you a generic instead of the name-brand drug, don’t assume it’s inferior. It’s not. It’s the same active ingredient. Same effect. Same safety profile. Just cheaper.

And if your generic isn’t working the way you expect? Talk to your doctor. Sometimes, inactive ingredients can cause minor differences in how a drug feels-like a pill dissolving slower or causing a slight stomach upset. But that’s rare. And if it happens, there’s almost always another generic version available.

Common Questions About the ANDA Process

Final Thoughts

The ANDA process isn’t perfect. It’s slow, complex, and sometimes frustrating for manufacturers. But it’s the reason you can fill a $300 prescription for $12. It’s why insulin, blood pressure meds, and antibiotics are accessible to people who need them most. Without it, the U.S. healthcare system would be unaffordable for millions.

The next time you pick up a generic, remember: behind that small pill is a decade of science, billions in savings, and a regulatory system designed to keep you healthy without breaking the bank.