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Glycerol Phenylbutyrate 1.1 g/mL Liquid — NDC 31722-0605-32 package photo

Glycerol Phenylbutyrate 1.1 g/mL Liquid

by Camber Pharmaceuticals, Inc. · 4 BOTTLE in 1 CARTON (31722-605-32) / 25 mL in 1 BOTTLE
NDC 31722-0605-32
🏷️ FDA NDC (as labeled) 31722-605-32 billing pads the product segment with a zero
This package
Contains25 mL in 1 bottle Pack sizes2 compare ↓
Also comes in: 25 mL 31722-0605-31
Rx only Generic On market Non-controlled
🗂️ Data synced Sep 10, 2026 · sources: openFDA · FDA label (DailyMed) · FDA Orange & Purple Book · First Databank · CMS NADAC, ASP, Medicare & Medicaid · RxNorm
📋 All sources & update times →

This page is curated, coded, and maintained by

Compiled from public FDA, CMS, DailyMed, NADAC, and related drug data sources. Editorial policy

🆔 Identity & classification

FDA NDC (as labeled) 31722-605-32
Product NDC 31722-605
11-digit billing NDC 31722060532
RxCUI 1368453
UNII ZH6F1VCV7B
UPC 0331722605311
Application # ANDA205742
SPL Set ID d3b52ded-b305-445c-b943-ef0fb2dedd2b
Established class (EPC) Nitrogen Binding Agent
Mechanism of action Ammonium Ion Binding Activity
DEA schedule Non-controlled
Marketing category ANDA
Marketing status On market
FDA listing status Listed (active directory)
Marketing start 2026-08-21
Route ORAL
Dosage form LIQUID
Substance GLYCEROL PHENYLBUTYRATE
GCN Seq No 070560
GCN 34137
HICL code 039990
Ingredient (HICL) Glycerol Phenylbutyrate
HIC1 code D
Therapeutic class — broad (HIC1) Biliary System/Gastro-Intestinal System
HIC2 code D9
Therapeutic class — intermediate (HIC2) Ammonia Inhibitors
HIC3 code D9A
Therapeutic class — specific (HIC3) Ammonia Inhibitors
AHFS code 40:10.00.00
AHFS class Ammonia Detoxicants
FDB label name GLYCEROL PHENYLBUT 1.1 GRAM/ML
FDB brand name Glycerol Phenylbutyrate
Legend status F — Federal legend — prescription drug or device
TE code (Orange Book) AA · RLD · RS
Why two NDCs? The FDA registers this code as 31722-605-32 — a 5-3-2 layout, and that's what's printed on the package and shown on DailyMed. For insurance claims, every NDC is standardized to a uniform 11-digit 5-4-2 format by adding a zero to the product segment → 31722-0605-32. Same drug, same package — only the format differs.
Where does this data come from?
Identifiers from the FDA openFDA NDC Directory and Structured Product Labeling; RxCUI from RxNorm (NLM); GPI from Medi-Span; GCN / HIC / AHFS / legend from First Databank.

🏷️ RxNorm drug class

This medicine belongs to the Various alimentary tract and metabolism products class.

Drug family (ATC) Various alimentary tract and metabolism products
Where does this data come from?
Therapeutic classes from RxNorm RxClass (U.S. National Library of Medicine) — Established Pharmacologic Class (FDA), ATC drug family (WHO) and mechanism of action, matched by this product’s RxCUI.

🏭 Manufacturer & labeler

LabelerCamber Pharmaceuticals, Inc.
Application holderPH HEALTH LTD
FDA applicationANDA205742 (ANDA)
Labeler code31722
First marketedAug 2026
Product typeHuman Prescription Drug
Portfolio603 products on file
The labeler markets the product; the application holder owns the FDA approval. They’re often the same company but can differ (e.g. a repackager or an authorized generic). A mailing address / phone appears here when the manufacturer includes it in the product’s FDA label (not all do).
Where does this data come from?
Labeler, application holder and registered establishment from the FDA openFDA NDC Directory and Drugs@FDA; address/contact from the product’s FDA label.

🩺 Clinical

Label name GLYCEROL PHENYLBUT 1.1 GRAM/ML Ingredient Glycerol Phenylbutyrate
📗 Our plain-language guide HelloPharmacist
  • Glycerol phenylbutyrate — sold as Ravicti or as a generic — is used to manage urea cycle disorders, which are rare inherited conditions where the body can't properly get rid of amm...
  • What exactly is this medication for, and why does my child need it?
  • Yes — the technique matters. Use the oral syringe that comes with the medication to measure the exact prescribed dose, and give it directly into the mouth. Always take it with food...
  • How should I give this medicine — is there a special technique?
📖 Read our full Glycerol Phenylbutyrate guide →

Supplement & herbal interactions

🌿 Drug–supplement interaction checker →
Where does this data come from?
Plain-language summary from MedlinePlus (U.S. National Library of Medicine); supplement & herbal interactions and nutrient depletion data from the Natural Medicines database; our full guide is HelloPharmacist editorial content.

🧪 Inactive Ingredients / Excipients

Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.

A current SPL was checked, but it does not contain a structured or narrative inactive-ingredient list for this product. This does not mean the product has no inactive ingredients.
Where does this data come from?
Source: official FDA Structured Product Labeling (SPL) via DailyMed and the openFDA label index. Structured IACT rows and label-wide narrative are kept separate; availability and product-level specificity depend on the submitted label.

Inactive ingredient FAQ

Are inactive ingredients the same for every manufacturer?
No. Inactive ingredients can differ by manufacturer, dosage form, strength, and package / product version.
Why might an inactive ingredient be missing?
Some SPLs do not provide a complete structured inactive-ingredient list, and older or unusual labels may only include the information in narrative text.
Can inactive ingredients matter?
Yes. They can matter for allergies, intolerances, dyes, gluten / lactose concerns, preservatives, and formulation differences — but confirm with a pharmacist or the manufacturer when it’s clinically important.

💲 Pricing

A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.

Price systemPer mLPer package
Retail pharmacies payNADAC · weekly Not in the retail survey — common for institutional, discontinued, or low-volume packs.
Medicaid paysCMS SDUD · 12 mo No recent Medicaid claims on file for this NDC — rare and low-volume NDCs are suppressed in the public data.
Medicare drug plans payPart D · quarterly No Part D plan price is available for this NDC in our data.
ℹ️
No price is published for this exact package yet. CMS surveys NADAC per package size, so a different pack of the same drug often has one.
Try another pack size: 25 mL
Where does this data come from?
NADAC (National Average Drug Acquisition Cost) is the CMS weekly pharmacy-acquisition-cost survey — what pharmacies pay. ASP (Average Sales Price) is the CMS Medicare Part B drug-payment file, published quarterly. Medicaid pays is computed by us from CMS State Drug Utilization Data (total reimbursed ÷ units, trailing 12 months) — gross of rebates and inclusive of dispensing fees, so it reflects what Medicaid paid, not an acquisition cost. Medicare drug plans pay is the median negotiated point-of-sale unit cost across plans listing this NDC in the CMS quarterly Prescription Drug Plan pricing files, before rebates. The VA pays is the federal contract price (FSS, and the statutory Big 4 ceiling where listed) from the VA National Acquisition Center pharmaceutical price file. All are free public government data; each measures a different payer, so the figures are not directly comparable.

🔁 Therapeutic equivalents

ProductLabelerPackNADAC/unitTEStatusPrice vs. this
Glycerol phenylbutyrate 1.1 g/mL 00480-3777-58 Teva 1 bottle — AA FDA listed —
Glycerol Phenylbutyrate 1.1 g/mLthis 31722-0605-32 Camber 4 bottles — AA FDA listed —
Glycerol Phenylbutyrate 1.1 g/mL 49884-0264-95 Par 1 bottle — AA FDA listed —
Glycerol Phenylbutyrate 1.1 g/mL 59651-0988-25 Aurobindo 1 bottle — AA FDA listed —
Glycerol Phenylbutyrate 1.1 g/mL 70710-2193-05 Zydus 1 bottle — AA FDA listed —
glycerol phenylbutyrate 1.1 g/mL 70748-0425-01 Lupin 1 bottle — AA FDA listed —
Glycerol phenylbutyrate 1.1 g/mL 72205-0331-57 Novadoz 1 bottle — AA FDA listed —
Ravicti 1.1 g/mL 75987-0050-06 Horizon 1 bottle — AA FDA listed —
About this product: this is a generic version of the medicine. FDA equivalence ratings are shown when available, and other versions are listed above, least expensive first.
Where does this data come from?
Equivalents are other NDCs of the same ingredient, form and route from the openFDA NDC Directory, ranked least-expensive-first by NADAC. Therapeutic-equivalence (AB) ratings come from the FDA Orange Book; biologics use the FDA Purple Book for biosimilar & interchangeable status.

⏳ Availability & generic status

🏛️
2021
First FDA approval
Dec 2021
📍
2026
Currently FDA-listed
5 years listed
🔓
·
Generic on the market
this product is a generic
✅This is a generic drug

This product is an FDA-approved generic. Other versions of the same drug are listed under Therapeutic equivalents, least expensive first.

🛡️ Latest patent/protection date listed: The latest listed FDA patent/protection lapsed Apr 2026 — those protections no longer apply, though a generic still needs FDA approval and a manufacturer to market it.
📅 FDA approved Dec 2, 2021 AA TE-rated RLD RS

Why the date isn’t exact: Generic timing can change because patents may be challenged, settled, licensed, added, removed, or worked around with a narrower label — and FDA approval does not always mean a pharmacy can get the generic today.

Patents & exclusivity — FDA Orange Book
Exclusivity PC
2021 2023 2025
Today
LOE
Substance patent Formulation patent Method-of-use patent Exclusivity Pediatric +6mo
🏛️FDA exclusivity
FDA-granted marketing protection. It’s separate from patents and may be shorter than patent protection.
🧪Product / substance patents
Patents covering the active ingredient, product, formulation, or related drug features.
🎯Method-of-use patents
Patents covering specific approved uses. These can sometimes be carved out with a “skinny label,” but not always.
🛈 What do these terms mean?
Patent
Legal protection listed in the Orange Book that may delay generic approval or launch. Issued by the U.S. Patent & Trademark Office.
Substance patent
Covers the active drug molecule itself — the hardest to design around. A generic generally can’t launch until it expires.
Formulation (product) patent
Covers a specific formulation or dosage form. A generic can sometimes work around it with a different formulation.
Method-of-use patent
A patent covering one specific approved use of the drug — not necessarily the whole molecule. A generic can sometimes launch with a “skinny label” that carves out the protected use and keeps the others.
Skinny label
A generic label that omits a still-patented use when the FDA allows it — letting a generic reach the market for the unprotected uses.
Exclusivity
FDA-granted marketing protection, separate from patents — e.g. 5-yr new chemical entity, 7-yr orphan drug, or a +6-month pediatric extension.
Paragraph IV
A generic applicant’s formal challenge to a listed patent. It can potentially lead to earlier generic entry, but often involves litigation or a settlement.
RLD / RS
Reference Listed Drug — the brand product the FDA uses as the reference for generic applications. Reference Standard — the product the FDA expects generics to compare against in bioequivalence testing.
TE / AB rating
FDA therapeutic-equivalence rating. An AB rating generally means the FDA considers a generic therapeutically equivalent to — and substitutable for — the brand.
LOE (loss of exclusivity)
The latest patent or exclusivity currently listed — the loss-of-exclusivity / latest-listed-protection date shown on this page. Paragraph-IV challenges and settlements can move the real date earlier; FDA approval and a manufacturer’s decision to market can move it later.

Built from the FDA Orange Book. The bars above are scaled to each protection’s expiry; the red LOE marker is the last one to lapse.

FDA exclusivity
CodeWhat it grantsExpires
PCPediatric Exclusivity (+6 months)Apr 15, 2026
Common questions
Is there a generic version of GLYCEROL PHENYLBUT 1.1 GRAM/ML?
Yes — an FDA-approved generic equivalent is listed in the FDA Orange Book for GLYCEROL PHENYLBUT 1.1 GRAM/ML. See the alternatives section for substitutable, lower-cost products.
The FDA approved a generic — why can’t I get it at my pharmacy yet?
FDA approval and pharmacy availability are two different things. The FDA can approve a generic years before it actually reaches pharmacies, because the brand company may still hold patents or have a settlement that delays the launch. A manufacturer also has to choose to make and sell it, and have supply ready. So a drug can be “FDA-approved generic exists” and still be brand-only at the counter today.
Why do different websites show different generic release dates?
Generic availability is not based on one single date. Some sources use the first exclusivity expiration, some use the last product patent, and others use the latest method-of-use patent. Patent challenges, settlements, licenses, and label carve-outs can also change the real-world launch date. This page shows the underlying Orange Book dates so you can see why estimates may differ.
What does “FDA listed” mean?
It means the product appears in the FDA’s official NDC directory. That’s a good sign a product exists and is intended for the U.S. market, but on its own it does not confirm a pharmacy can fill it today. Where we have recent retail pricing data (NADAC) for a product, we label it “Availability likely” instead.
What does a patent or protection date mean here?
It’s the latest date currently listed in the FDA Orange Book for a patent or exclusivity on the brand product. It can affect when a full generic version becomes widely available — but it is not a guaranteed generic launch date. Generics sometimes arrive earlier (through a settlement or patent challenge) or later (a manufacturer still has to make and sell one).
What does “current Orange Book estimate” mean?
It means we are using the latest patent and exclusivity dates currently listed in the FDA Orange Book. It is not a guaranteed launch date.
Can a generic come out before the last patent expires?
Sometimes. A generic company may challenge a patent, settle with the brand manufacturer, receive a license, or obtain approval with a narrower label that avoids a patented use. In other cases, the last listed protection may delay full-label generic competition.
Can a generic come out after the listed dates?
Yes. Even after patents or exclusivity expire, a generic still needs FDA approval and a manufacturer must choose to market it. Supply, litigation, business decisions, or regulatory issues can delay actual availability.
What is the difference between patents and exclusivity?
Patents are legal protections usually issued by the U.S. Patent and Trademark Office. FDA exclusivity is marketing protection granted by the FDA. They are separate, and either one can affect generic timing.
Why are there multiple patent dates?
One drug can have several patents covering different things: the active ingredient, a formulation, a manufacturing process, or a specific approved use. That is why a page may show several expiration dates instead of one simple generic date.
Built from FDA Orange Book patent and exclusivity data. Dates are refreshed from public FDA data when available; the marker is max(latest patent expiry, latest exclusivity expiry). Paragraph-IV settlements and first-filer 180-day exclusivity can shift the real date; a method-of-use patent may allow an earlier skinny-label generic for non-protected indications. Generic launch timing is an estimate, not a guarantee.
Where does this data come from?
Patents and exclusivity from the FDA Orange Book (small-molecule drugs), refreshed from public FDA data. Generic launch timing is an estimate, not a guarantee.

📊 Medicare Part D spend CMS · PART D · 2026 (Q1)

Medicare Part D (outpatient prescription) spending for Glycerol Phenylbutyrate — the program that covers self-administered drugs. 2 manufacturers.
⚠️ Drug-level data: CMS publishes Part D spending by drug, not by NDC — these figures combine every manufacturer, strength and package size sold under the name Glycerol Phenylbutyrate. That’s a different level of aggregation than the Medicaid card above, which is specific to this exact 11-digit NDC (pack size included), so the two aren’t directly comparable.
Period
Total Part D spend
$5.4M
Claims incl. refills
87
Beneficiaries
41
Spend / beneficiary
$131,820.43
Spend / claim
$62,122.27
Trend by period
💵 About the dollar figures: spending is what Part D plans paid before confidential manufacturer rebates, so the program’s real net cost is lower. A blank patient count means fewer than 11 people — CMS hides counts that small to protect privacy. Source: CMS Medicare Quarterly Part D Spending by Drug (data.cms.gov), updated quarterly.

🔬 Reported adverse events (FAERS)

Read carefully: FAERS reports are voluntary and unverified. Counts are not incidence, do not establish causation, are subject to reporting bias, and cannot be used to compare one drug to another. Shown for signal context only. Reports for Glycerol Phenylbutyrate (this brand).

Top reported reactions

Hyperammonaemic Crisis5
Hyperammonaemic Encephalopathy5
Ammonia Increased3
Hyperammonaemia3
Myelosuppression3
Condition Aggravated2
Feeling Abnormal2

Reporter sex

32 reports

Serious outcomes

Hospitalization19
Life-threatening2
Reports over time (by year) — tap or hover for the count & year
2019 2021 2023 2026 3 0
Most recent year is provisional (FAERS lags ~3 months).
Where does this data come from?
Adverse-event reports from the FDA Adverse Event Reporting System (FAERS) via openFDA. FAERS reports are voluntary and unverified — counts are not incidence and don’t establish causation.

📦 Packaging — all sizes for this product

Package NDCDescription Marketing startStatus
31722-0605-31 1 BOTTLE in 1 CARTON (31722-605-31) / 25 mL in 1 BOTTLE 2026-08-21 Active
31722-0605-32 You're viewing this 4 BOTTLE in 1 CARTON (31722-605-32) / 25 mL in 1 BOTTLE 2026-08-21 Active

Pack size FAQ

What quantity is in NDC 31722-0605-32?
NDC 31722-0605-32 is listed by the FDA — 4 bottle in 1 carton / 25 ml in 1 bottle.
What NDC number is used to bill for this package of Glycerol Phenylbutyrate 1.1 g/mL Liquid?
Bill NDC 31722-0605-32 — the 11-digit billing format is 31722060532. Pharmacy and medical claims use the 11-digit form; the FDA label may print a shorter form of the same code.

🧭 About this NDC listing & data coverage

Finished prescription product
What data is (and isn’t) available for this NDC — tap to expand
NDC identity (package / product / labeler codes) ✓ Available
Labeler ✓ Available
Product & package description ✓ Available
Marketing category & status ✓ Available
Active ingredient / dosage form / route ✓ Available
FDA label (SPL via DailyMed) ✓ Available
Package photos ✓ Available
Inactive ingredients (structured) — Not published for this NDC The labeler did not submit a structured excipient list, or no SPL is available.
NADAC pharmacy acquisition price (CMS) — Not published for this NDC CMS publishes NADAC only for NDCs reported in its retail-pharmacy survey.
Orange Book / therapeutic-equivalence data ✓ Available
HCPCS J-code billing crosswalk — Not published for this NDC Most self-administered / retail products have no J-code — that is normal.
Medicaid utilization (CMS SDUD) — Not published for this NDC CMS reports utilization only for NDCs with Medicaid claims above its privacy threshold.
“Not published” reflects what the public FDA / CMS / NLM sources provide for this exact package code — it is a property of the data feeds, not a judgment about the product.

Questions about this listing

Why is there no price listed?
The pricing shown on our NDC pages comes from CMS NADAC, a voluntary survey of retail community pharmacy invoices. CMS does not publish a NADAC for every NDC — packages outside the retail survey (institutional and hospital products, bulk packages, discontinued items, and many OTC items) may never receive one. A missing price reflects the survey's scope, not this product's actual cost, and does not mean the product is free or unavailable.
Is the NDC printed on the package the same as the 11-digit billing NDC?
Yes, they identify this exact package in different formats. The FDA registers it as 31722-605-32, which is what is printed on the packaging and shown on DailyMed. Insurance claims use a fixed 11-digit 5-4-2 format, so the short segment is padded with a leading zero: 31722-0605-32, written without dashes as 31722060532. The Identity section at the top of this page lists every form of this code.
What do the three segments of this NDC mean?
In 31722-0605-32, the first segment (31722) is the labeler code FDA assigned to Camber Pharmaceuticals, Inc.; the middle segment (0605) identifies this specific product — its ingredient, strength, and dosage form; and the last segment (32) identifies this exact package size and type. Together they name one specific package of one specific product.
Is this package still being marketed?
Yes, per the latest FDA NDC Directory data on this page: this package is listed as actively marketed, with no marketing end date reported by Camber Pharmaceuticals, Inc.. Listing status can change — the directory data on this page refreshes weekly.
Does this product come in other package sizes?
Yes — the FDA directory lists 1 other package presentation of this same product, including 1 bottle (31722-0605-31). Each has its own NDC and its own page — see the package list near the top of this page.
Who lists this product with the FDA?
Camber Pharmaceuticals, Inc. is the labeler of record for this NDC — the company under whose FDA-assigned code the package is listed. The labeler may be the manufacturer itself or a distributor marketing the product under its own code.
Do I need a prescription for this product?
This NDC is listed with FDA as a prescription product, so it is dispensed under a prescriber's order. Your pharmacist can tell you whether any over-the-counter forms of the same medication exist.
This page identifies an FDA-listed package (the NDC) and reports public regulatory and pricing data about the listing. It is reference information, not a medical recommendation — talk to your pharmacist or prescriber about your own medication.
Where does this data come from?
Listing facts (marketing category, packager status, marketing dates) from the FDA openFDA NDC Directory; label availability from DailyMed; pricing coverage from CMS NADAC; equivalence scope from the FDA Orange Book.

📄 Full prescribing information FDA SPL

The complete FDA label for this product — the official prescribing information, verbatim, section by section. Jump with a chip, search within the label, or expand everything.
🎯 Indications and Usage ⏱️ Dosage and Administration 💊 Dosage Forms and Strengths ⛔ Contraindications ⚠️ Warnings and Cautions 🤒 Adverse Reactions 🔄 Drug Interactions 👥 Use in Specific Populations 🤰 Pregnancy 🧒 Pediatric Use 🧓 Geriatric Use 🆘 Overdosage 🧬 Clinical Pharmacology 🧬 Mechanism of Action 📦 How Supplied / Storage and Handling 📋 Description 💬 Information for Patients 💬 Medication Guide
🎯 Indications and Usage 213 words ▾

1 INDICATIONS AND USAGE Glycerol phenylbutyrate oral liquid is indicated for use as a nitrogen-binding agent for chronic management of patients with urea cycle disorders (UCDs) who cannot be managed by dietary protein restriction and/or amino acid supplementation alone. Glycerol phenylbutyrate oral liquid must be used with dietary protein restriction and, in some cases, dietary supplements (e.g., essential amino acids, arginine, citrulline, protein-free calorie supplements). Limitations of Use : • Glycerol phenylbutyrate oral liquid is not indicated for the treatment of acute hyperammonemia in patients with UCDs because more rapidly acting interventions are essential to reduce plasma ammonia levels. • The safety and efficacy of glycerol phenylbutyrate oral liquid for the treatment of N -acetylglutamate synthase (NAGS) deficiency has not been established.

Glycerol phenylbutyrate is a nitrogen-binding agent indicated for chronic management of patients with urea cycle disorders (UCDs) who cannot be managed by dietary protein restriction and/or amino acid supplementation alone. Glycerol phenylbutyrate oral liquid must be used with dietary protein restriction and, in some cases, dietary supplements. ( 1 ) Limitations of Use: • Glycerol phenylbutyrate oral liquid is not indicated for treatment of acute hyperammonemia in patients with UCDs.

( 1 ) • Safety and efficacy for treatment of N-acetylglutamate synthase (NAGS) deficiency has not been established. ( 1 )

⏱️ Dosage and Administration ~3 min read ▾

2 DOSAGE AND ADMINISTRATION • Glycerol phenylbutyrate oral liquid should be prescribed by a physician experienced in management of UCDs. For administration and preparation, see full prescribing information. ( 2.1 , 2.6 ) Switching From Sodium Phenylbutyrate Tablets or Powder to Glycerol Phenylbutyrate Oral Liquid : • Patients should receive the dosage of glycerol phenylbutyrate that contains the same amount of phenylbutyric acid, see full prescribing information for conversion.

( 2.2 ) Initial Dosage in Phenylbutyrate-Naïve Patients ( 2.3 ) : • Recommended dosage range is 4.5 to 11.2 mL/m 2 /day (5 to 12.4 g/m 2 /day). • For patients with some residual enzyme activity not adequately controlled with dietary restriction, the recommended starting dose is 4.5 mL/m 2 /day. • Take into account patient's estimated urea synthetic capacity, dietary • protein intake, and diet adherence. Dosage Adjustment and Monitoring : • Follow plasma ammonia levels to determine the need for dosage titration. ( 2.4 ) Dosage Modifications in Patients with Hepatic Impairment : • Start dosage at lower end of range.

( 2.5 , 8.7 )

2.1Important Administration Instructions Glycerol phenylbutyrate oral liquid should be prescribed by a physician experienced in the management of UCDs. Instruct patients to take glycerol phenylbutyrate oral liquid with food or formula and to administer directly into the mouth via oral syringe. Instruct patients to use the glycerol phenylbutyrate oral liquid bottle and oral syringe as follows: Use a new reclosable bottle cap adapter with each new bottle that is opened.

Open the glycerol phenylbutyrate oral liquid bottle and twist on the new reclosable bottle cap adapter. Use a new and dry oral syringe to withdraw each prescribed dose of glycerol phenylbutyrate oral liquid. Discard the oral syringe after each dose.

Tightly close the tethered tab on the reclosable bottle cap adapter after each use. Do not rinse the reclosable bottle cap adapter. Discard bottle and any remaining contents 28 days after opening.

If water or moisture enters the glycerol phenylbutyrate oral liquid bottle, the contents will become cloudy in appearance. If the contents of the bottle appear cloudy at any time, do not use the remaining glycerol phenylbutyrate oral liquid in the bottle and return it to the pharmacy to be discarded. Instruct that glycerol phenylbutyrate oral liquid should be administered just prior to breastfeeding in infants who are breastfeeding.

For patients who cannot swallow, see the instructions on administration of glycerol phenylbutyrate oral liquid by nasogastric tube or gastrostomy tube [see Dosage and Administration ( 2.6 )] . For patients who require a volume of less than 1 mL per dose via nasogastric or gastrostomy tube, the delivered dose may be less than anticipated. Closely monitor these patients using ammonia levels [see Dosage and Administration ( 2.6 )] .

The recommended dosages for patients switching from sodium phenylbutyrate to glycerol phenylbutyrate oral liquid and patients naïve to phenylbutyric acid are different [see Dosage and Administration ( 2.2 , 2.3 )] . For both subpopulations: Patients 2 years of age and older: Give glycerol phenylbutyrate oral liquid in 3 equally divided dosages, each rounded up to the nearest 0.5 mL Patients less than 2 years: Give glycerol phenylbutyrate oral liquid in 3 or more equally divided dosages, each rounded up to the nearest 0.1 mL.

The maximum total daily dosage is 17.5 mL (19 g). Glycerol phenylbutyrate oral liquid must be used with dietary protein restriction and, in some cases, dietary supplements (e.g., essential amino acids, arginine, citrulline, protein-free calorie supplements).

2.2Switching From Sodium Phenylbutyrate to Glycerol Phenylbutyrate Oral Liquid Patients switching from sodium phenylbutyrate to glycerol phenylbutyrate oral liquid should receive the dosage of glycerol phenylbutyrate oral liquid that contains the same amount of phenylbutyric acid. The conversion i…

💊 Dosage Forms and Strengths 29 words ▾

3 DOSAGE FORMS AND STRENGTHS Oral liquid: clear, colorless to pale yellow, 1.1 g/mL of glycerol phenylbutyrate (delivers 1.02 g/mL of phenylbutyrate). Oral liquid: 1.1 g/mL. ( 3 )

⛔ Contraindications 34 words ▾

4 CONTRAINDICATIONS Glycerol phenylbutyrate oral liquid is contraindicated in patients with known hypersensitivity to phenylbutyrate. Signs of hypersensitivity include wheezing, dyspnea, coughing, hypotension, flushing, nausea, and rash. Known hypersensitivity to phenylbutyrate. ( 4 )

⚠️ Warnings and Cautions ~2 min read ▾

5 WARNINGS AND PRECAUTIONS • Neurotoxicity: Phenylacetate (PAA), the active moiety of glycerol phenylbutyrate, may be toxic; reduce dosage for symptoms of neurotoxicity. ( 5.1 ) • Pancreatic Insufficiency or Intestinal Malabsorption: Monitor ammonia levels closely. ( 5.2 )

5.1Neurotoxicity Increased exposure to PAA, the major metabolite of glycerol phenylbutyrate, may be associated with neurotoxicity in patients with UCDs. In a study of adult cancer patients, subjects received sodium phenylacetate administered as a 1-hour infusion twice daily at two dose levels of 125 and 150 mg/kg for a 2-week period. Of 18 subjects enrolled, 7 had a history of primary central nervous system tumor.

Signs and symptoms of potential PAA neurotoxicity, which were reversible, were reported at plasma PAA concentrations above 500 micrograms/mL and included somnolence, fatigue, lightheadedness, headache, dysgeusia, hypoacusis, disorientation, impaired memory, and exacerbation of preexisting neuropathy. PAA concentrations were not measured when symptoms resolved. In healthy subjects, after administration of 4 mL and 6 mL glycerol phenylbutyrate 3 times daily (13.2 g/day and 19.8 g/day, respectively) for 3 days, a dosedependent increase in non-serious nervous system adverse reactions were observed.

In subjects who had nervous system adverse reactions, plasma PAA concentrations, which were measured on Day 3 per protocol and not always at onset of symptoms, ranged from 8 to 56 micrograms/mL with 4 mL glycerol phenylbutyrate 3 times daily and from 31 to 242 micrograms/mL with 6 mL glycerol phenylbutyrate 3 times daily. In clinical trials in patients with UCDs who had been on sodium phenylbutyrate prior to administration of glycerol phenylbutyrate, adverse reactions of headache, fatigue, symptoms of peripheral neuropathy, seizures, tremor and/or dizziness were reported.

No correlation between plasma PAA concentration and neurologic symptoms was identified but plasma PAA concentrations were generally not consistently measured at the time of neurologic symptom occurrence [see Clinical Pharmacology (12.3)]. If symptoms of vomiting, nausea, headache, somnolence or confusion are present in the absence of high ammonia or other intercurrent illness which explains these symptoms, consider the potential for PAA neurotoxicity which may need reduction in the glycerol phenylbutyrate dosage [see Dosage and Administration (2.4)].

5.2Pancreatic Insufficiency or Intestinal Malabsorption Exocrine pancreatic enzymes hydrolyze glycerol phenylbutyrate in the small intestine, separating the active moiety, phenylbutyrate, from glycerol. This process allows phenylbutyrate to be absorbed into the circulation. Low or absent pancreatic enzymes or intestinal disease resulting in fat malabsorption may result in reduced or absent digestion of glycerol phenylbutyrate and/or absorption of phenylbutyrate and reduced control of plasma ammonia.

Monitor ammonia levels closely in patients with pancreatic insufficiency or intestinal malabsorption.

🤒 Adverse Reactions ~3 min read ▾

6 ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in the labeling: Neurotoxicity [ see Warnings and Precautions (5.1) ] Pancreatic insufficiency or Intestinal Malabsorption [ see Warnings and Precautions (5.2) ] Most common adverse reactions (≥10%) in adults are: diarrhea, flatulence, and headache. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Camber Pharmaceuticals, Inc. at 1-866-495-1995 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .

6.1Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. Assessment of adverse reactions was based on exposure of 45 adult patients (31 female and 14 male) with UCD subtype deficiencies of ornithine transcarbamylase (OTC, n=40), carbamoyl phosphate synthetase (CPS, n=2), and argininosuccinate synthetase (ASS, n=1) in a randomized, double-blind, active-controlled (glycerol phenylbutyrate vs sodium phenylbutyrate), crossover, 4-week study (Study 1) that enrolled patients 18 years of age and older [see Clinical Studies ( 14.1 )] .

One of the 45 patients received only sodium phenylbutyrate prior to withdrawing on day 1 of the study due to an adverse reaction. The most common adverse reactions (occurring in at least 10% of patients) reported during short-term treatment with glycerol phenylbutyrate were diarrhea, flatulence, and headache. Table 1 summarizes adverse reactions occurring in 2 or more patients treated with glycerol phenylbutyrate or sodium phenylbutyrate (incidence of at least 4% in either treatment arm).

Table 1: Adverse Reactions Reported in 2 or More Adult Patients with UCDs (at least 4% in Either Treatment Arm) in Study 1 Number (%) of Patients in Study 1 Sodium Phenylbutyrate (N = 45) Glycerol Phenylbutyrate (N = 44) Diarrhea 3 (7) 7 (16) Headache 4 (9) 6 (14) Flatulence 1 (2) 6 (14) Abdominal pain 2 (4) 3 (7) Vomiting 2 (4) 3 (7) Decreased appetite 2 (4) 3 (7) Fatigue 1 (2) 3 (7) Dyspepsia 3 (7) 2 (5) Nausea 3 (7) 1 (2) Dizziness 4 (9) 0 Abdominal discomfort 3 (7) 0 Other Adverse Reactions Glycerol phenylbutyrate has been evaluated in 77 patients with UCDs (51 adult and 26 pediatric patients ages 2 years to 17 years) in 2 open-label long-term studies, in which 69 patients completed 12 months of treatment with glycerol phenylbutyrate (median exposure = 51 weeks).

During these studies there were no deaths. Adverse reactions reported in at least 10% of adult patients were nausea, vomiting, diarrhea, decreased appetite, dizziness, headache, and fatigue. Adverse reactions reported in at least 10% of pediatric patients ages 2 years to 17 years were upper abdominal pain, rash, nausea, vomiting, diarrhea, decreased appetite, and headache.

Glycerol phenylbutyrate has been evaluated in 17 patients with UCDs ages 2 months to less than 2 years in 3 open-label studies. The median exposure was 6 months (range 0.2 to 20 months). Adverse reactions reported in at least 10% of pediatric patients aged 2 months to less than 2 years were neutropenia, vomiting, constipation, diarrhea, pyrexia, hypophagia, cough, nasal congestion, rhinorrhea, rash, and papule.

Glycerol phenylbutyrate has been evaluated in 16 patients with UCDs less than 2 months of age (age range 0.1 to 2 months, median age 0.5 months) in a single, open-label study. The median exposure was 10 months (range 2 to 20 months). Adverse reactions reported in at least 10% of pediatric patients aged less than 2 months were vomiting, rash, gastroesophageal reflux, increased hepatic enzymes, feeding disorder (decreased appetite, hypophagia), anemia, cough, dehydration, metabolic acidosis, thrombocytosis, thrombocytopenia, neutropenia, lymphocytosis, diarrhea, flatulence, constipation, pyrexia, lethargy, and irritability/agitation.

6.2 Postmarket…

🔄 Drug Interactions ~1 min read ▾

7 DRUG INTERACTIONS • Corticosteroids, valproic acid, or haloperidol : May increase plasma ammonia level; monitor ammonia levels closely. ( 7.1 ) • Probenecid : May affect renal excretion of metabolites of glycerol phenylbutyrate, including phenylacetylglutamine (PAGN) and PAA. ( 7.2 ) • CYP3A4 Substrates with narrow therapeutic index (e.g., alfentanil, quinidine, cyclosporine) : Glycerol phenylbutyrate may decrease exposure; monitor for decreased efficacy of the narrow therapeutic index drug.

( 7.3 ) • Midazolam : Decreased exposure; monitor for suboptimal effect of midazolam. ( 7.3 )

7.1Potential for Other Drugs to Affect Ammonia Corticosteroids Use of corticosteroids may cause the breakdown of body protein and increase plasma ammonia levels. Monitor ammonia levels closely when corticosteroids and glycerol phenylbutyrate are used concomitantly. Valproic Acid and Haloperidol Hyperammonemia may be induced by haloperidol and by valproic acid.

Monitor ammonia levels closely when use of valproic acid or haloperidol is necessary in patients with UCDs.

7.2Potential for Other Drugs to Affect Glycerol Phenylbutyrate Probenecid Probenecid may inhibit the renal excretion of metabolites of glycerol phenylbutyrate including PAGN and PAA.

7.3Potential for Glycerol Phenylbutyrate to Affect Other Drugs Drugs with narrow therapeutic index that are substrates of CYP3A4 Glycerol phenylbutyrate is a weak inducer of CYP3A4 in humans. Concomitant use of glycerol phenylbutyrate may decrease the systemic exposure to drugs that are substrates of CYP3A4. Monitor for decreased efficacy of drugs with narrow therapeutic index (e.g., alfentanil, quinidine, cyclosporine) [see Clinical Pharmacology ( 12.3 )] .

Midazolam Concomitant use of glycerol phenylbutyrate decreased the systemic exposure of midazolam. Monitor for suboptimal effect of midazolam in patients who are being treated with glycerol phenylbutyrate.

👥 Use in Specific Populations ~3 min read ▾

8 USE IN SPECIFIC POPULATIONS Lactation : Breastfeeding is not recommended. ( 8.2 )

8.1Pregnancy Risk Summary Limited available data with glycerol phenylbutyrate use in pregnant women are insufficient to inform a drug-associated risk of major birth defects and miscarriage. In an animal reproduction study, administration of oral glycerol phenylbutyrate to pregnant rabbits during organogenesis at doses up to 2.7–times the dose of 6.87 mL/m 2 /day in adult patients resulted in maternal toxicity, but had no effects on embryo-fetal development. In addition, there were no adverse developmental effects with administration of oral glycerol phenylbutyrate to pregnant rats during organogenesis at 1.9 times the dose of 6.87 mL/m 2 /day in adult patients; however, maternal toxicity, reduced fetal weights, and variations in skeletal development were observed in pregnant rats administered oral glycerol phenylbutyrate during organogenesis at doses greater than or equal to 5.7 times the dose of 6.87 mL/m 2 /day in adult patients [ see Data] .

The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.

Data Animal Data Oral administration of glycerol phenylbutyrate during the period of organogenesis up to 350 mg/kg/day in rabbits produced maternal toxicity, but no effects on embryo-fetal development. The dose of 350 mg/kg/day in rabbits is approximately 2.7 times the dose of 6.87 mL/m 2 /day in adult patients, based on combined area under the plasma concentration-time curve [AUCs] for PBA and PAA. In rats, at an oral dose of 300 mg/kg/day of glycerol phenylbutyrate (1.9 times the dose of 6.87 mL/m 2 /day in adult patients, based on combined AUCs for PBA and PAA) during the period of organogenesis, no effects on embryo-fetal development were observed.

Doses of 650 mg/kg/day or greater produced maternal toxicity and adverse effects on embryo-fetal development including reduced fetal weights and cervical ribs at the 7th cervical vertebra. The dose of 650 mg/kg/day in rats is approximately 5.7 times the dose of 6.87 mL/m 2 /day in adult patients, based on combined AUCs for PBA and PAA. No developmental abnormalities, effects on growth, or effects on learning and memory were observed through maturation of offspring following oral administration in pregnant rats with up to 900 mg/kg/day of glycerol phenylbutyrate (8.5 times the dose of 6.87 mL/m 2 /day in adult patients, based on combined AUCs for PBA and PAA) during organogenesis and lactation.

8.2Lactation Risk Summary There are no data on the presence of glycerol phenylbutyrate in human milk, the effects on the breastfed infant, or the effects on milk production. Because of the potential for serious adverse reactions, including neurotoxicity and tumorigenicity in a breastfed infant, advise patients that breastfeeding is not recommended during treatment with glycerol phenylbutyrate.

8.4Pediatric Use Patients 2 Years to 17 Years of Age The safety and effectiveness of glycerol phenylbutyrate in patients 2 years to less than 18 years of age have been established in 3 clinical studies: 2 open-label, fixed-sequence, switchover clinical studies from sodium phenylbutyrate to glycerol phenylbutyrate, and 1 long-term, open label safety study [see Adverse Reactions ( 6.1 ), Clinical Studies ( 14.2 )] . Patients Less Than 2 Years of Age The safety and effectiveness of glycerol phenylbutyrate in patients with UCDs less than 2 years of age have been established in 3 open-label studies.

Pharmacokinetics and pharmacodynamics (plasma ammonia), and safety were studied in 17 patients aged 2 months to less than 2 years of age and in 16 patients less than 2 months of age [see Adverse Reactions ( 6.1 ), C…

🤰 Pregnancy ~2 min read ▾

8.1Pregnancy Risk Summary Limited available data with glycerol phenylbutyrate use in pregnant women are insufficient to inform a drug-associated risk of major birth defects and miscarriage. In an animal reproduction study, administration of oral glycerol phenylbutyrate to pregnant rabbits during organogenesis at doses up to 2.7–times the dose of 6.87 mL/m 2 /day in adult patients resulted in maternal toxicity, but had no effects on embryo-fetal development. In addition, there were no adverse developmental effects with administration of oral glycerol phenylbutyrate to pregnant rats during organogenesis at 1.9 times the dose of 6.87 mL/m 2 /day in adult patients; however, maternal toxicity, reduced fetal weights, and variations in skeletal development were observed in pregnant rats administered oral glycerol phenylbutyrate during organogenesis at doses greater than or equal to 5.7 times the dose of 6.87 mL/m 2 /day in adult patients [ see Data] .

The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.

Data Animal Data Oral administration of glycerol phenylbutyrate during the period of organogenesis up to 350 mg/kg/day in rabbits produced maternal toxicity, but no effects on embryo-fetal development. The dose of 350 mg/kg/day in rabbits is approximately 2.7 times the dose of 6.87 mL/m 2 /day in adult patients, based on combined area under the plasma concentration-time curve [AUCs] for PBA and PAA. In rats, at an oral dose of 300 mg/kg/day of glycerol phenylbutyrate (1.9 times the dose of 6.87 mL/m 2 /day in adult patients, based on combined AUCs for PBA and PAA) during the period of organogenesis, no effects on embryo-fetal development were observed.

Doses of 650 mg/kg/day or greater produced maternal toxicity and adverse effects on embryo-fetal development including reduced fetal weights and cervical ribs at the 7th cervical vertebra. The dose of 650 mg/kg/day in rats is approximately 5.7 times the dose of 6.87 mL/m 2 /day in adult patients, based on combined AUCs for PBA and PAA. No developmental abnormalities, effects on growth, or effects on learning and memory were observed through maturation of offspring following oral administration in pregnant rats with up to 900 mg/kg/day of glycerol phenylbutyrate (8.5 times the dose of 6.87 mL/m 2 /day in adult patients, based on combined AUCs for PBA and PAA) during organogenesis and lactation.

🧒 Pediatric Use ~1 min read ▾

8.4Pediatric Use Patients 2 Years to 17 Years of Age The safety and effectiveness of glycerol phenylbutyrate in patients 2 years to less than 18 years of age have been established in 3 clinical studies: 2 open-label, fixed-sequence, switchover clinical studies from sodium phenylbutyrate to glycerol phenylbutyrate, and 1 long-term, open label safety study [see Adverse Reactions ( 6.1 ), Clinical Studies ( 14.2 )] . Patients Less Than 2 Years of Age The safety and effectiveness of glycerol phenylbutyrate in patients with UCDs less than 2 years of age have been established in 3 open-label studies.

Pharmacokinetics and pharmacodynamics (plasma ammonia), and safety were studied in 17 patients aged 2 months to less than 2 years of age and in 16 patients less than 2 months of age [see Adverse Reactions ( 6.1 ), Clinical Studies ( 14.3 )]. Juvenile Animal Toxicity Data In a juvenile rat study with daily oral dosing performed on postpartum day 2 through mating and pregnancy after maturation, terminal body weight was 2 dose-dependently reduced by up to 16% in males and 12% in females at 900 mg/kg/day or higher (3 times the dose of 6.87 mL/m /day in adult patients, based on combined AUCs for PBA and PAA).

Learning, memory, and motor activity endpoints were not affected. However, fertility (number of pregnant 2 rats) was decreased by up to 25% at 650 mg/kg/day or higher (2.6 times the dose of 6.87 mL/m /day in adult patients, based on combined AUCs for PBA and PAA).

🧓 Geriatric Use 86 words ▾

8.5Geriatric Use Clinical studies of glycerol phenylbutyrate did not include sufficient numbers of subjects 65 years of age and older to determine whether they respond differently than younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.

🆘 Overdosage 56 words ▾

10 OVERDOSAGE While there is no experience with overdosage in human clinical trials, PAA, a toxic metabolite of glycerol phenylbutyrate, can accumulate in patients who receive an overdose [see Warnings and Precautions ( 5.1 )] . If over-exposure occurs, call your Poison Control Center at 1-800-222-1222 for current information on the management of poisoning or overdosage.

🧬 Clinical Pharmacology ~3 min read ▾

12 CLINICAL PHARMACOLOGY

12.1Mechanism of Action UCDs are inherited deficiencies of enzymes or transporters necessary for the synthesis of urea from ammonia (NH3, NH4 + ). Absence of these enzymes or transporters results in the accumulation of toxic levels of ammonia in the blood and brain of affected patients. Glycerol phenylbutyrate is a triglyceride containing 3 molecules of PBA.

PAA, the major metabolite of PBA, is the active moiety of glycerol phenylbutyrate. PAA conjugates with glutamine (which contains 2 molecules of nitrogen) via acetylation in the liver and kidneys to form PAGN, which is excreted by the kidneys (Figure 1). On a molar basis, PAGN, like urea, contains 2 moles of nitrogen and provides an alternate vehicle for waste nitrogen excretion.

Figure 1: Glycerol Phenylbutyrate Mechanism of Action glycerolphenylbutyratefigure1

12.2Pharmacodynamics Pharmacological Effects In clinical studies, total 24-hour area under the plasma concentration-time curve (AUC) of ammonia levels was comparable at steady state during the switchover period between glycerol phenylbutyrate and sodium phenylbutyrate [see Clinical Studies (14)]. Cardiac Electrophysiology The effect of multiple doses of glycerol phenylbutyrate 13.2 g/day and 19.8 g/day (approximately 69% and 104% of the maximum recommended daily dosage) on QTc interval was evaluated in a randomized, placebo- and active-controlled (moxifloxacin 400 mg), four-treatment-arm, crossover study in 57 healthy subjects.

The upper bound of the one-sided 95% CI for the largest placebo-adjusted, baseline-corrected QTc, based on individual correction method (QTcI) for glycerol phenylbutyrate, was below 10 ms.

12.3Pharmacokinetics Absorption Glycerol phenylbutyrate is a pro-drug of PBA. Upon oral ingestion, PBA is released from the glycerol backbone in the gastrointestinal tract by lipases. PBA derived from glycerol phenylbutyrate is further converted by β-oxidation to PAA.

In healthy, fasting adult subjects receiving a single oral dose of 2.9 mL/m 2 of glycerol phenylbutyrate, peak plasma levels of PBA, PAA, and PAGN occurred at 2 hours, 4 hours, and 4 hours, respectively. Upon single-dose administration of glycerol phenylbutyrate, plasma concentrations of PBA were quantifiable in 15 of 22 participants at the first sample time postdose (0.25 hours). Mean maximum concentration (C max ) for PBA, PAA, and PAGN was 37.0 micrograms/mL, 14.9 micrograms/mL, and 30.2 micrograms/mL, respectively.

In healthy subjects, intact glycerol phenylbutyrate was detected in plasma. While the study was inconclusive, the incomplete hydrolysis of glycerol phenylbutyrate cannot be ruled out. In healthy subjects, the systemic exposure to PAA, PBA, and PAGN increased in a dose-dependent manner.

Following 4 mL of glycerol phenylbutyrate 3 times a day for 3 days, the mean C max and AUC were 66 micrograms/mL and 930 micrograms•h/mL for PBA and 28 micrograms/mL and 942 micrograms•h/mL for PAA, respectively. In the same study, following 6 mL of glycerol phenylbutyrate three times a day for 3 days, mean C max and AUC were 100 micrograms/mL and 1400 micrograms•h/mL for PBA and 65 mcg/mL and 2064 micrograms•h/mL for PAA, respectively. In adult patients with UCDs receiving multiple doses of glycerol phenylbutyrate, maximum plasma concentrations at steady state (C max,ss ) of PBA, PAA, and PAGN occurred at 8 hours, 12 hours, and 10 hours, respectively, after the first dose in the day.

Intact glycerol phenylbutyrate was not detectable in plasma in patients with UCDs. In clinical studies of glycerol phenylbutyrate in patients with UCDs, the peak observed PAA concentrations by age group are shown in Table 2. Table 2: Peak PAA Concentrations in Patients with UCDs Treated with Glycerol Phenylbutyrate in Clinical Trials Age Range Glycerol Phenylbutyrate Dose Mean Peak PAA Concentration* (SD) Median Peak PAA Concentration * (Range) Less than 2 months (n=16) 3.1 to 12.7 mL/m 2 /day (3.4 to 14 g/m 2 /day) 257 (162) 205 (96 to 70…

🧬 Mechanism of Action 127 words ▾

12.1Mechanism of Action UCDs are inherited deficiencies of enzymes or transporters necessary for the synthesis of urea from ammonia (NH3, NH4 + ). Absence of these enzymes or transporters results in the accumulation of toxic levels of ammonia in the blood and brain of affected patients. Glycerol phenylbutyrate is a triglyceride containing 3 molecules of PBA.

PAA, the major metabolite of PBA, is the active moiety of glycerol phenylbutyrate. PAA conjugates with glutamine (which contains 2 molecules of nitrogen) via acetylation in the liver and kidneys to form PAGN, which is excreted by the kidneys (Figure 1). On a molar basis, PAGN, like urea, contains 2 moles of nitrogen and provides an alternate vehicle for waste nitrogen excretion.

Figure 1: Glycerol Phenylbutyrate Mechanism of Action glycerolphenylbutyratefigure1

📦 How Supplied / Storage and Handling 74 words ▾

16 HOW SUPPLIED/STORAGE AND HANDLING Glycerol Phenylbutyrate Oral Liquid 1.1 g/mL is supplied in multi-use, 25 mL glass bottles. The bottles are supplied in the following configurations: • NDC 31722-605-31: Single 25 mL bottle per carton • NDC 31722-605-32: Four 25 mL bottles per carton Store at 20° to 25°C (68° to 77°F), with excursions permitted to 15° to 30°C (59° to 86°F) [see USP Controlled Room Temperature]. Discard bottle 28 days after opening.

📋 Description 80 words ▾

11 DESCRIPTION Glycerol phenylbutyrate is a clear, colorless to pale yellow oral liquid. It is soluble in dimethylsulfoxide (DMSO) and in dimethyl formamide. Glycerol phenylbutyrate is a nitrogen-binding agent.

It is a triglyceride containing 3 molecules of PBA linked to a glycerol backbone, the chemical name of which is benzenebutanoic acid, 1', 1' ' –(1,2,3-propanetriyl) ester with a molecular weight of 530.67. It has a molecular formula of C 33 H 38 O 6 . The structural formula is: glycerolphenylbutyratestructure

💬 Information for Patients ~2 min read ▾

17 PATIENT COUNSELING INFORMATION Advise the patient to read the FDA-approved patient labeling (Medication Guide). Neurotoxicity [see Warnings and Precautions ( 5.1 )] . Inform patients/caregivers that adverse reactions of glycerol phenylbutyrate are sometimes the same as symptoms of high blood ammonia.

Neurological adverse reactions may also be associated with the major metabolite of glycerol phenylbutyrate, PAA, and may be reversible. Blood tests for PAA may be done to measure the amount of PAA in the blood. Instruct the patient/caregiver to contact the healthcare provider immediately if the patient experiences: nausea, vomiting, headache, fatigue, somnolence, lightheadedness, confusion, exacerbation of preexisting neuropathy, disorientation, impaired memory, dysgeusia, or hypoacusis.

Lactation Advise patients that breastfeeding is not recommended during treatment with glycerol phenylbutyrate [see Use in Specific Populations ( 8.2 )]. Administration Instruct patients to take glycerol phenylbutyrate with food or formula and to administer directly into the mouth via oral syringe. Instruct patients to use the glycerol phenylbutyrate bottle and oral syringe as follows: Use a new reclosable bottle cap adapter with each new bottle that is opened.

Open the glycerol phenylbutyrate bottle and twist on the new reclosable bottle cap adapter. Use a new and dry oral syringe to withdraw each prescribed dose of glycerol phenylbutyrate. Discard the oral syringe after each dose.

Tightly close the tethered tab on the reclosable bottle cap adapter after each use. Do not rinse the reclosable bottle cap adapter. Discard bottle and any remaining contents 28 days after opening.

If water or moisture enters the glycerol phenylbutyrate bottle, the contents will become cloudy in appearance. If the contents of the bottle appear cloudy at any time, do not use the remaining glycerol phenylbutyrate in the bottle and return it to the pharmacy to be discarded. Instruct that glycerol phenylbutyrate should be administered just prior to breastfeeding in infants who are breastfeeding.

Instruct patients to take glycerol phenylbutyrate orally, even if they have a nasogastric and/or gastrostomy tube. For patients who cannot swallow and who have a nasogastric tube or gastrostomy tube in place, instruct patients/caregivers to administer glycerol phenylbutyrate as follows: Utilize a new dry oral syringe to withdraw the prescribed dosage of glycerol phenylbutyrate from the bottle. Place the tip of the syringe into the gastrostomy/nasogastric tube.

Utilizing the plunger of the syringe, administer glycerol phenylbutyrate into the tube. Use a separate syringe to flush the nasogastric/gastrostomy tube. Flush once with 10 mL of water or formula and allow the flush to drain.

If needed, flush a second time with an additional 10 mL of water or formula to clear the tube. Manufactured for: Camber Pharmaceuticals, Inc. Piscataway, NJ 08854.

By: Annora Pharma Pvt. Ltd. Sangareddy - 502313, Telangana, India.

Revised: 03/2026 glycerolphenylbutyratecamberlogo

💬 Medication Guide ~3 min read ▾

MEDICATION GUIDE Glycerol Phenylbutyrate Oral Liquid (glis-er-ol-fen-il-bue-ti-rate) What is the most important information I should know about glycerol phenylbutyrate oral liquid? Glycerol phenylbutyrate oral liquid may cause serious side effects, including: Nervous system problems (Neurotoxicity). Phenylacetate (PAA), a breakdown product of glycerol phenylbutyrate oral liquid, may cause nervous system side effects.

Call your doctor or get medical help right away if you get any of these symptoms while taking glycerol phenylbutyrate oral liquid: • sleepiness • worsening of numbness, tingling, or burning in your hands or feet • lightheadedness • change in taste • headache • problems with hearing • feeling very tired (fatigue) • confusion • nausea • problems with memory • vomiting Your doctor may do blood tests to measure the amount of PAA in your blood during your treatment with glycerol phenylbutyrate oral liquid. What is glycerol phenylbutyrate oral liquid?

Glycerol phenylbutyrate oral liquid is a prescription medicine used for long-term management of high blood levels of ammonia (hyperammonemia) caused by a condition called a urea cycle disorder (UCD). Glycerol phenylbutyrate oral liquid should be used if the UCD cannot be managed with a low protein diet and dietary supplements alone. Glycerol phenylbutyrate oral liquid must be used along with a low protein diet and in some cases dietary supplements.

Glycerol phenylbutyrate oral liquid is not used for the acute treatment of hyperammonemia in people with UCD. It is not known if glycerol phenylbutyrate oral liquid is safe and effective for the treatment of N-acetylglutamate synthase (NAGS) deficiency. Do not take glycerol phenylbutyrate oral liquid if you are allergic to phenylbutyrate.

Call your doctor or go to the nearest hospital emergency room if you have wheezing, shortness of breath, cough, low blood pressure, flushing, nausea or a rash while taking glycerol phenylbutyrate oral liquid. Before taking glycerol phenylbutyrate oral liquid, tell your doctor about all of your medical conditions, including if you: have liver or kidney problems have pancreas or bowel (intestine) problems are pregnant or plan to become pregnant. It is not known if glycerol phenylbutyrate will harm your unborn baby. are breastfeeding or plan to breastfeed.

It is not known if glycerol phenylbutyrate passes into your breast milk. Breastfeeding is not recommended during treatment with glycerol phenylbutyrate oral liquid. Talk to your doctor about the best way to feed your baby if you take glycerol phenylbutyrate oral liquid.

Tell your doctor about all the medicines you take, including prescription and over-the-counter medicines, vitamins, dietary and herbal supplements. Know the medicines you take. Keep a list of them to show your doctor and pharmacist when you get a new medicine.

How should I take glycerol phenylbutyrate oral liquid? Take glycerol phenylbutyrate oral liquid exactly as your doctor tells you. Your doctor will tell you how much glycerol phenylbutyrate oral liquid to take and when to take it.

Your doctor may change your dose if needed. Take glycerol phenylbutyrate oral liquid with food or formula. In an infant who is breastfeeding, give glycerol phenylbutyrate oral liquid just before breastfeeding.

Glycerol phenylbutyrate is an oral liquid that is taken by mouth using an oral syringe. Ask your pharmacist for oral syringes and a reclosable bottle cap adapter for each bottle you receive if you do not have them. Use the glycerol phenylbutyrate oral liquid bottle and oral syringe as follows: Use a new reclosable bottle cap adapter with each new glycerol phenylbutyrate oral liquid bottle that is opened.

Open the glycerol phenylbutyrate oral liquid bottle and twist on the new reclosable bottle cap adapter. Use a new dry oral syringe to remove each prescribed dose of glycerol phenylbutyrate oral liquid. Throw away (discard) the oral syringe after each dose.

Tightly close the tethered tab on th…

Source: FDA Structured Product Labeling, mirrored from DailyMed / openFDA. Prefer the government’s original formatting? View this label on DailyMed ↗
← 31722-0603-12 · Camber 31722-0607-05 · Camber →
For educational and professional reference only — not medical advice. Pricing reflects published NADAC and CMS ASP (free public data) and may differ from your acquisition cost; always verify before billing or dispensing.