INOmax Generic: When Will Generic Nitric Oxide Be Available?
This page is aggregated from FDA records, court filings and company announcements. Coded and designed by Dr. Brian Staiger, PharmD, BCPS
Updated October 9, 2026 How we build our data
INOmax Generic at a Glance
Four quick answers from FDA records and our estimate.
- When is the first generic expected? June 2029 About 2.5 years away Why then?
- Has the FDA approved a generic? Not yet None in the FDA’s records yet
- When does the last patent end? November 2036 16 patents listed with the FDA Why is a generic expected sooner?
- Can you buy a generic today? Yes 2 companies list one
It already is. A generic nitric oxide is listed for sale by 2 companies, so ask your pharmacy whether it can fill your prescription with one.
Why June 2029?
It is when INOmax’s patent 11,931,377 ends. That patent covers the active ingredient, the product’s formulation and a way of using it, and once it ends, generics should be able to go on sale as soon as the FDA approves them. We rate it probable: more likely than not, but it can still move.
If INOmax’s last patent runs to November 2036, how can a generic come sooner?
The 16 patents that run past the expected month, to November 2036 (8,282,966, 8,293,284, 8,431,163, 8,795,741 and 12 more), cover a way of using it, the active ingredient and the product’s formulation. A generic can still come sooner if a court rules a patent invalid or not infringed, or if the companies settle on an earlier date. Generic companies have been challenging INOmax’s patents with the FDA since May 2014. That is why the expected month comes before the last protection ends. See the road to a generic
What should I do now?
Ask your pharmacy whether it can fill your prescription with a generic. It may look different from INOmax, but the active ingredient, strength and form are the same. What a generic means for you
Our month is only an estimate based on available information, so we never name a day.
INOmax by the Numbers
- Reason
- Patent expiresA patent that protects the brand runs out. After that, approved generics can be sold.
- How sure
- Probable More likely than not, but it can still move.
- Price competition
- None filed yet No filers on record
- Brand sales
- Sales not reported
- FDA approved 1999 December 1999 FDA Orange Book
- Patents listed 16 last runs to November 2036 FDA Orange Book
INOmax’s Road to a Generic
INOmax has had the market to itself since the FDA approved it in December 1999 (Mallinckrodt Pharmaceuticals Ireland Ltd). Its 16 listed patents run to November 2036. Generic companies have challenged its patents with the FDA since May 2014.
The first generic of INOmax is expected in June 2029.
Why that month: patent 11,931,377, on the active ingredient, the product’s formulation and a way of using it, ends then. That is about 7.5 years before the last listed patent runs out, in November 2036.
Why a Generic Can Come Before November 2036
The last listed patent runs to November 2036; a court ruling or a settlement can bring a generic sooner. Dr. Brian explains
Each bar runs from the brand’s approval to the day that protection ends. The green band is our projection for the first generic: a month, never a day, because legal dates move and a generic reaches shelves days to weeks after it is allowed. Sources: FDA Orange Book; the expected month from court records and company announcements.
INOmax Patents and FDA Protections
Every patent and exclusivity the FDA Orange Book lists for INOmax’s own applications. A protection running past the expected month does not mean the date is wrong: a settlement or a court ruling can let a generic in before a patent ends, and a patent on one formulation or use does not block every generic.
The one that matters for a generic launch: patent 11,931,377, which ends in December 2029. Why the later ones may not hold it back
| Patent | What it covers | Protects until | Status |
|---|---|---|---|
| 8,282,966 | A way of using it (U-1286) | December 2029 with the pediatric extension | Active |
| 8,293,284 | A way of using it (U-1286) | December 2029 with the pediatric extension | Active |
| 8,431,163 | A way of using it (U-1286) | December 2029 with the pediatric extension | Active |
| 8,795,741 | A way of using it (U-1286) | December 2029 with the pediatric extension | Active |
| 8,846,112 | A way of using it (U-1286) | December 2029 with the pediatric extension | Active |
| 11,931,377 Sets the expected month of generic availability | The active ingredient; the product’s formulation; a way of using it (U-3903) | December 2029 with the pediatric extension | Active |
| 8,291,904 | The product’s formulation; a way of using it (U-1226) | July 2031 with the pediatric extension | Active |
| 8,573,209 | The product’s formulation | July 2031 with the pediatric extension | Active |
| 8,573,210 | The product’s formulation; a way of using it (U-1453) | July 2031 with the pediatric extension | Active |
| 8,776,794 | The product’s formulation; a way of using it (U-1226) | July 2031 with the pediatric extension | Active |
| 8,776,795 | The product’s formulation; a way of using it (U-1226) | July 2031 with the pediatric extension | Active |
| 9,265,911 | The product’s formulation; a way of using it (U-1824) | July 2031 with the pediatric extension | Active |
| 9,295,802 | The product’s formulation; a way of using it (U-1226) | July 2031 with the pediatric extension | Active |
| 9,408,993 | The product’s formulation; a way of using it (U-1824) | July 2031 with the pediatric extension | Active |
| 9,279,794 | The product’s formulation; a way of using it (U-1823) | August 2035 with the pediatric extension | Active |
| 9,770,570 | A way of using it (U-2148) | November 2036 with the pediatric extension | Active |
Source: FDA Orange Book, application 020845. Patent numbers open the patent on Google Patents.
Patent Challenges to INOmax
The first patent challenge to INOmax reached the FDA in May 2014, from one company on that first day. A first challenger began selling its generic in April 2019.
What Is a Patent Challenge?
A generic company that wants to sell its version before INOmax’s patents run out can tell the FDA that a patent is invalid, or that its version does not infringe it. The FDA calls this a “Paragraph IV certification.” The brand company usually sues, and the FDA then generally cannot approve that generic for up to 30 months while the case runs. To reward going first, the companies that challenge first can get a 180-day head start: the FDA cannot approve the generics that came after them until it ends.
| Product | First challenged | Companies that day | 180-day head start | First challenger’s generic | Challenged patents run to | |
|---|---|---|---|---|---|---|
| Approved | On sale | |||||
| For inhalation, 100 ppm and 800 ppm | May 2014 | 1 company | Decision deferred decided November 2019 | October 2018 | April 2019 | January 2031 |
Source: the FDA’s Paragraph IV Patent Certifications list, as of September 2026. The FDA began posting the 180-day decisions and the first challenger’s approval and first sale in June 2019: an older entry it has not updated since reads “Not posted”, and “Not yet” means the list records no such event. “Companies that day” is the FDA’s count of challenges that arrived on the first day.
Who Is Lined Up to Make Generic Nitric Oxide
Three steps stand between a brand and a generic you can buy: a company applies to the FDA, the FDA approves it, and the company starts selling it.
Applied to the FDA
No company is recorded as having applied to the FDA to make a generic INOmax yet.
Generic companies have challenged INOmax’s patents with the FDA since May 2014: see the patent challenges.
Approved by the FDA
Not yet. The FDA has not approved a generic nitric oxide. Final approval often comes close to the day a generic can be sold.
For Sale in Pharmacies
Yes. A generic nitric oxide is listed for sale by 2 companies. Ask your pharmacy whether it can fill your prescription with it.
Airgas Therapeutics, LLC and VERO BIOTECH, INC.
Sources: how many companies have applied, from court records and company announcements; approved generics from the FDA Orange Book; tentative approvals from Drugs@FDA; what is for sale from the FDA NDC Directory. The FDA does not disclose an application before it approves it (21 CFR 314.430).
INOmax Price: What Pharmacies Pay and What Generics Usually Do
What a Generic Could Cost
How we estimate it. The national survey of what pharmacies pay (NADAC) has no recent price for INOmax, so we cannot show dollars. Here is the FDA’s finding of how far the price pharmacies pay usually falls as generic companies join: about 31% with one company, 44% with two, 73% with four and over 95% with six or more (the typical drop for every drug whose first generic came out from 2015 to 2017).
Median prices pharmacies paid for the generic (invoice prices), compared with the brand’s price before generic entry, from FDA’s 2019 analysis “Generic Competition and Drug Prices”. At the manufacturer’s price FDA found steeper drops (about 39%, 54%, 79% and over 95%), the figures quoted elsewhere on this tracker. A typical pattern, not a price quote for this medicine.
INOmax Strengths and Forms
| Strength | Form | How it is taken | Approved | Status |
|---|---|---|---|---|
| 800PPM | Gas | Inhalation | December 1999 | Prescription reference product |
| 4880PPM | Gas | Inhalation | January 2023 | Prescription reference product |
| 100PPM **Federal Register determination that product was not discontinued or withdrawn for safety or effectiveness reasons** | Gas | Inhalation | December 1999 | Discontinued reference product |
Source: FDA Orange Book, Mallinckrodt Pharmaceuticals Ireland Ltd. Listed for sale today by Ino Therapeutics LLC (FDA NDC Directory).
INOmax NDC Codes and Packages
Each INOmax package sold today has its own NDC, the product number printed on the box and on the pharmacy label. Open one to see that package’s details, what pharmacies pay for it and its patent timeline.
| NDC | Product | Package | Company |
|---|---|---|---|
| 64693-0002-01 | NITRIC OXIDE .98 mg/L gas | cylinder of 353 l | INO Therapeutics LLC |
| 64693-0002-01 | NITRIC OXIDE .98 mg/L gas | cylinder of 353 l | INO Therapeutics LLC |
| 64693-0002-02 | NITRIC OXIDE .98 mg/L gas | cylinder of 1,963 l | INO Therapeutics LLC |
| 64693-0002-02 | NITRIC OXIDE .98 mg/L gas | cylinder of 1,963 l | INO Therapeutics LLC |
| 64693-0003-01 | NITRIC OXIDE 6 mg/L gas | cylinder of 78 l | INO Therapeutics LLC |
| 64693-0003-01 | NITRIC OXIDE 6 mg/L gas | cylinder of 78 l | INO Therapeutics LLC |
Source: the FDA NDC Directory, current listings only. Only packages sold under INOmax’s own FDA approval (NDA 20845) are listed, never a generic. Some codes belong to companies that repackage INOmax: it is the same medicine in a different package.
What a Generic INOmax Means for You
Nothing Changes Until It Is in Pharmacies
A generic is listed for sale now, so your pharmacy may already be able to fill your prescription with it.
Your Pharmacy May Switch You Automatically
Every state lets pharmacists fill a brand-name prescription with an FDA-approved generic rated as equivalent to it, and about 19 states require them to, unless your prescriber writes “dispense as written” or “brand medically necessary” on the prescription. Some states ask the pharmacist to tell you, or to get your OK first. A study of every state’s law has the details.
It Will Probably Look Different
US trademark law does not let a generic look exactly like the brand, so the color, shape or markings usually change. The active ingredient, strength and form are the same. An “authorized generic,” made by or for the brand’s own company, can look identical. The FDA explains.
Your Insurance May Change Too
Once a lower-cost version is available, many insurance plans charge more for the brand, or stop covering it. Your plan’s drug list (formulary) says how.
Questions people ask about INOmax
Is there a generic for INOmax right now?
Yes. The FDA NDC Directory lists a generic nitric oxide from 2 companies. Ask your pharmacy whether it can fill your prescription with it.
When will INOmax go generic?
It already has. The FDA NDC Directory lists a generic nitric oxide from 2 companies, so ask your pharmacy whether it can fill your prescription with one.
Will generic nitric oxide be the same as INOmax?
Yes in the ways that matter: the same active ingredient, strength and form, with proof that it reaches your blood the same way. Inactive ingredients can differ, which is why some people notice a different look or taste.
How much will the generic cost?
Nobody can say for sure before launch. No company is recorded as having applied to the FDA to make one yet, and a single company usually brings only a modest drop.
Has the FDA approved a generic INOmax?
Not yet. The FDA Orange Book lists no approved generic version of INOmax.
When does the INOmax patent expire?
The FDA Orange Book lists 16 patents for INOmax; the last runs to November 2036, counting a six-month pediatric extension. The one behind the expected month is patent 11,931,377, which ends in December 2029. A patent date is not the launch date: settlements and court rulings often bring a generic earlier, and FDA approval or a company’s own plans can make it later. The expected month on this page (June 2029) weighs all of that.
Has anyone challenged the INOmax patents?
Yes. The first patent challenge to INOmax reached the FDA in May 2014, from one company on that first day. A first challenger began selling its generic in April 2019. A patent challenge (a “Paragraph IV certification”) is a generic company telling the FDA that a patent listed for the brand is invalid or will not be infringed by its version. The first companies to file one can earn a 180-day head start, during which the FDA cannot approve the generics that filed after them.
Changes to This Projection
- First generic expected June 2029 on this month’s schedule. A line is added here whenever a monthly update moves the month, the reason or how sure it is.
Every change to the expected month is logged here with the month we saw it.
Also Going Generic
- PlenvuAscorbic Acid, Polyethylene Glycol 3350, Potassium Chloride, Sodium Ascorbate, Sodium Chloride, and Sodium Sulfate2028 to 2029
- TerlivazTerlipressin AcetateMarch 2030
- YcanthCantharidinJanuary 2031
- BrekiyaDihydroergotamine MesylateAugust 2039
- LilettaLevonorgestrelSeptember 2040
- FinaceaAzelaic AcidTBD no date yet
About INOmax
- Generic name nitric oxide
- How it is taken Inhaled
- Company Mallinckrodt Pharmaceuticals Ireland Ltd
- Patent challenges Since May 2014 (FDA)
- More drugs Brand-name drugs starting with I
- Have a question? A pharmacist answers, free. Ask about INOmax
Sources. The expected month: FDA Paragraph IV Patent Certifications list, federal court records, company announcements and securities filings (settlement dates, launch plans, sales). The record on this page: FDA Orange Book, Drugs@FDA (tentative approvals), FDA NDC Directory, FDA Paragraph IV Patent Certifications list, FDA, Generic Competition and Drug Prices (2019). Updated October 9, 2026. Information, not medical advice.