K252684 · Medtox Diagnostics, Inc. · DJG · Jan 29, 2026 · Clinical Toxicology
Device Facts
Record ID
K252684
Device Name
Labcorp Fentanyl Urine Visual Test
Applicant
Medtox Diagnostics, Inc.
Product Code
DJG · Clinical Toxicology
Decision Date
Jan 29, 2026
Decision
SESE
Submission Type
Traditional
Regulation
21 CFR 862.3650
Device Class
Class 2
Indications for Use
The Labcorp Fentanyl Urine Visual Test is a lateral flow competitive immunoassay for the rapid qualitative detection of norfentanyl (fentanyl metabolite) in human urine at a cutoff of 5 ng/mL. It is intended for prescription use. For in vitro diagnostic use only. This test provides only a preliminary result. Clinical consideration and professional judgment must be applied to any drug test result, particularly in evaluating a preliminary positive result. To confirm preliminary positive results, a more specific analytical method must be used. Gas Chromatography-Mass Spectrometry (GC-MS), Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS), and High Performance Liquid Chromatography (HPLC) are the preferred confirmatory methods.
Device Story
Lateral flow competitive immunoassay; detects norfentanyl in human urine. Input: urine sample via disposable dropper into cassette. Principle: drug-protein conjugate on membrane competes with norfentanyl in sample for binding to colloidal gold-labeled drug-specific antibodies. Negative result: visible line at test position (antibodies bind conjugate). Positive result: no line at test position (antibodies bind drug in sample). Control line confirms proper flow. Used in clinical settings; interpreted visually by healthcare professionals. Provides preliminary results; requires confirmation by GC-MS, LC-MS/MS, or HPLC. Aids clinical decision-making regarding drug use.
Clinical Evidence
Bench testing only. Method comparison study evaluated 87 clinical urine samples against LC-MS/MS reference method. Precision/reproducibility studies conducted using spiked urine samples across 0-200% of cutoff concentrations. Analytical specificity, cross-reactivity, and interference testing performed with endogenous compounds, common drugs, and fentanyl analogs.
Technological Characteristics
Lateral flow competitive immunoassay; colloidal gold-labeled antibody technology. Cassette format with disposable dropper. Single-use. Qualitative visual readout. No electronic components or software. Shelf life 2 years at 2-30°C.
Indications for Use
Indicated for the rapid qualitative detection of norfentanyl in human urine at a 5 ng/mL cutoff. Intended for prescription use in clinical settings for preliminary screening of drug presence.
Regulatory Classification
Identification
An opiate test system is a device intended to measure any of the addictive narcotic pain-relieving opiate drugs in blood, serum, urine, gastric contents, and saliva. An opiate is any natural or synthetic drug that has morphine-like pharmocological actions. The opiates include drugs such as morphine, morphine glucoronide, heroin, codeine, nalorphine, and meperedine. Measurements obtained by this device are used in the diagnosis and treatment of opiate use or overdose and in monitoring the levels of opiate administration to ensure appropriate therapy.
Special Controls
*Classification.* Class II (special controls). An opiate test system is not exempt if it is intended for any use other than employment or insurance testing or is intended for Federal drug testing programs. The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 862.9, provided the test system is intended for employment and insurance testing and includes a statement in the labeling that the device is intended solely for use in employment and insurance testing, and does not include devices intended for Federal drug testing programs (*e.g.,* programs run by the Substance Abuse and Mental Health Services Administration (SAMHSA), the Department of Transportation (DOT), and the U.S. military).
Predicate Devices
Chemtrue® Drug Screen Fentanyl/Tramadol Cup Test (K232736)
Chemtrue® Drug Screen Fentanyl/Tramadol Dip Card Test (K232736)
Chemtrue® Multi-Panel Drug Screen Cup Test (K232736)
Chemtrue® Multi-Panel Drug Screen Dip Card Test (K232736)
Submission Summary (Full Text)
{0}
FDA
U.S. FOOD & DRUG
ADMINISTRATION
# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY
ASSAY ONLY
## I Background Information:
A 510(k) Number
K252684
B Applicant
MEDTOX Diagnostics, Inc.
C Proprietary and Established Names
Labcorp Fentanyl Urine Visual Test
D Regulatory Information
| Product Code(s) | Classification | Regulation Section | Panel |
| --- | --- | --- | --- |
| DJG | Class II | 21 CFR 862.3650 - Opiate Test System | TX - Clinical Toxicology |
## II Submission/Device Overview:
A Purpose for Submission: New device
B Measurand: Norfentanyl
C Type of Test: Qualitative
## III Intended Use/Indications for Use:
A Intended Use(s): See Indications for Use below.
B Indication(s) for Use:
Food and Drug Administration
10903 New Hampshire Avenue
Silver Spring, MD 20993-0002
www.fda.gov
{1}
The Labcorp Fentanyl Urine Visual Test is a lateral flow competitive immunoassay for the rapid qualitative detection of norfentanyl (fentanyl metabolite) in human urine at a cutoff of 5 ng/mL. It is intended for prescription use. For in vitro diagnostic use only.
This test provides only a preliminary result. Clinical consideration and professional judgment must be applied to any drug test result, particularly in evaluating a preliminary positive result. To confirm preliminary positive results, a more specific analytical method must be used. Gas Chromatography-Mass Spectrometry (GC-MS), Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS), and High Performance Liquid Chromatography (HPLC) are the preferred confirmatory methods.
## C Special Conditions for Use Statement(s):
Rx - For Prescription Use Only
## D Special Instrument Requirements:
This 510(k) premarket submission for the Labcorp Fentanyl Urine Visual Test assay only.
## IV Device/System Characteristics:
### A Device Description:
The Labcorp Fentanyl Urine Visual Test is a lateral flow competitive immunoassay for the rapid qualitative detection of Norfentanyl (nFEN), the primary urinary metabolite of Fentanyl, in human urine at concentrations above 5 ng/mL. It is intended for prescription use.
The single-use, in vitro diagnostic device is available in a cassette format with a disposable dropper provided for sample transfer.
The Labcorp Fentanyl Urine Visual Test contains a test strip that gives a qualitative result for presence of Norfentanyl in human urine. The test is read visually and has labeling with instructions for interpreting test results.
### B Principle of Operation:
The Labcorp Fentanyl Urine Visual Test uses lateral flow immunoassay technology in which a modified drug (drug-protein conjugate) completes with drug that may be present in the urine. The colorless drug-protein conjugate is applied to the membrane of the test strip at the test line position. The colored drug-specific antibody-colloidal gold is applied to the sample pad of the test strip. When urine is transferred onto the sample pad it dissolves and migrates the colored antibody-colloidal gold across the strip membrane. If drug is not present or is below the cutoff, the drug-specific antibodies will bind to the conjugate line on the membrane and the colloidal gold will form a visible line, which indicates a negative result. If drug is present in the urine, the drug-specific antibodies will bind to the drug in solution and bypass the conjugate on the membrane and no line will form, which indicates a preliminary positive result.
A visible control line should form in the control line position regardless of whether drug is present to indicate that the test has been performed properly.
K252684 - Page 2 of 11
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V Substantial Equivalence Information:
A Predicate Device Name(s):
Chemtrue® Drug Screen Fentanyl/Tramadol Cup Test, Chemtrue® Drug Screen Fentanyl/Tramadol Dip Card Test, Chemtrue® Multi-Panel Drug Screen Cup Test, Chemtrue® Multi-Panel Drug Screen Dip Card Test
B Predicate 510(k) Number(s):
K232736
C Comparison with Predicate(s):
| Device & Predicate Device(s): | K252684 | K232736 |
| --- | --- | --- |
| Device Trade Name | Labcorp Fentanyl Urine Visual Test | Chemtrue® Drug Screen Fentanyl Cup/Dip Card Tests |
| General Device Characteristic Similarities | | |
| Indications For Use | Qualitative detection of norfentanyl in human urine at a cut-off of 5 ng/mL | Same |
| General Device Characteristic Differences | | |
| Test Device Format | Cassette | Cup/Dip Card |
VI Standards/Guidance Documents Referenced:
CLSI EP07 3rd Edition - Interference Testing in Clinical Chemistry
VII Performance Characteristics (if/when applicable):
A Analytical Performance:
1. Precision/Reproducibility:
These studies were carried out using urine samples containing norfentanyl (nFEN) spiked into a drug-free urine pool with LC-MS/MS confirmed concentrations of 0%, 25%, 50%, 75%, 100%, 125%, 150%, and 200% of the test cutoff. These samples were prepared in a blind randomized panel in triplicate and evaluated by 3 in-house operators over 5 days using 3 different lots. Each result was visually interpreted at 10 minutes. Results are summarized below:
| Test | Concentration Tested | Lot 1 Neg/Pos | Lot 2 Neg/Pos | Lot 3 Neg/Pos | Total Neg/Pos |
| --- | --- | --- | --- | --- | --- |
| nFEN | Negative | 45/0 | 45/0 | 45/0 | 135/0 |
K252684 - Page 3 of 11
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K252684 - Page 4 of 11
| Test | Concentration Tested | Lot 1 Neg/Pos | Lot 2 Neg/Pos | Lot 3 Neg/Pos | Total Neg/Pos |
| --- | --- | --- | --- | --- | --- |
| | 25% of Cutoff | 45/0 | 45/0 | 45/0 | 135/0 |
| | 50% of Cutoff | 45/0 | 45/0 | 45/0 | 135/0 |
| | 75% of Cutoff | 40/5 | 35/10 | 31/14 | 106/29 |
| | Cutoff | 20/25 | 22/23 | 18/27 | 60/75 |
| | 125% of Cutoff | 3/24 | 8/37 | 3/42 | 14/121 |
| | 150% of Cutoff | 0/45 | 0/45 | 0/45 | 0/135 |
| | 200% of Cutoff | 0/45 | 0/45 | 0/45 | 0/135 |
2. **Linearity:**
Not applicable because this device is intended for qualitative use only for detection of norfentanyl in human urine at concentrations above 5 ng/mL.
3. **Analytical Specificity/Interference:**
Interference and cross-reactivity studies were conducted based upon recommendations in the Clinical and Laboratory Standards Institute (CLSI) Guideline EP05-A3: Evaluation of Precision of Quantitative Measurement Methods. Test concentrations were determined using medically relevant calculations based on maximum daily doses, urinary excretion percentages, and minimum urine volumes. At least 9 professional laboratory operators performed visual readings.
For each drug and cutoff, specificity was evaluated by spiking various concentrations of similarly structured drug compounds into drug-free urine. Results are expressed as a minimum concentration of metabolite or compound required to produce a response approximately equivalent to the cutoff concentration of the assay. The percent cross reactivity of those compounds is listed below (if no cross reactivity was observed, the highest concentration tested is shown as <1%):
| Compound | Concentration | % Cross-Reactivity |
| --- | --- | --- |
| Norfentanyl (nFEN) (Norfentanyl, 5 ng/mL) | | |
| Parent drug: Fentanyl | 7.5 ng/mL | 67% |
| Fentanyl/Norfentanyl analog cross-reactants | | |
| 3-Methylfentanyl | 150 ng/mL | 3% |
| 4-Fluoro-Isobutyryl Fentanyl | 15 ng/mL | 33% |
| 4’-Methylacetyl Fentanyl (para-Methacetyl Fentanyl) | 750 ng/mL | 1% |
| Acetyl Fentanyl | 5 ng/mL | 100% |
| Acetyl Norfentanyl | 50 ng/mL | 10% |
| Acryl Fentanyl | 10 ng/mL | 50% |
| Alfentanil | 2,500 ng/mL | < 1% |
| Butyryl Fentanyl | 10 ng/mL | 50% |
| Cis-DL-3-Methylfentanyl | 100 ng/mL | 5% |
| Cyclopropyl Fentanyl | 10 ng/mL | 50% |
{4}
Interference from endogenous compounds and non-structurally related exogenous compounds using samples containing drugs at 50% of cutoff and 150% of cutoff urine samples. Each compound and urine sample were tested by running at least 5 replicates and 3 lots. The following endogenous compounds showed no interference at the concentrations listed:
| Endogenous Compound | Concentration (ng/mL) | Endogenous Compound | Concentration (ng/mL) |
| --- | --- | --- | --- |
| Acetone | 10,000,000 | Glucose | 30,000,000 |
| Albumin, Human | 5,000,000 | Hemoglobin, Human | 3,000,000 |
| Ascorbic Acid | 5,000,000 | Niacinamide | 100,000 |
| Atropine | 100,000 | Nicotinic Acid | 100,000 |
| Beta-Hydroxybutyric Acid | 100,000 | Octopamine | 150,000 |
| Bilirubin | 20,000 | Oxalic Acid | 100,000 |
| Biotin | 100,000 | Potassium Chloride | 10,000,000 |
| Calcium Chloride | 3,000,000 | Pyridoxine | 90,000 |
| Cholesterol | 100,000 | Quinolinic Acid | 100,000 |
| Creatine Hydrate | 100,000 | Riboflavin | 75,000 |
| Creatinine | 5,000,000 | Sodium Chloride | 10,000,000 |
| Deoxycorticosterone | 100,000 | Thiamine | 100,000 |
| Dopamine (3-Hydroxytyramine) | 100,000 | Tryptamine | 100,000 |
| Ethanol | 10,000,000 | Tyramine | 100,000 |
| Galactose | 100,000 | Urea | 60,000,000 |
| Gamma Globulin | 5,000,000 | Uric Acid | 100,000 |
| Cyclopropyl Norfentanyl | 7.5 ng/mL | 67% |
| --- | --- | --- |
| Fluorocyclopropyl Fentanyl (para-Fluorocyclopropyl Fentanyl) | 15 ng/mL | 33% |
| Furanyl Fentanyl | 25 ng/mL | 20% |
| Furanyl Norfentanyl | 7.5 ng/mL | 67% |
| (±) β-Hydroxythiofentanyl | 10 ng/mL | 50% |
| Isobutyryl Fentanyl | 7.5 ng/mL | 67% |
| Isobutyryl Norfentanyl | 5 ng/mL | 100% |
| Methoxyacetylfentanyl (MAF) | 15 ng/mL | 33% |
| N-Benzylfuranyl Norfentanyl | 50 ng/mL | 10% |
| N-Benzyl-Para-Fluoro Norfentanyl | 25 ng/mL | 20% |
| Octfentanil | 500 ng/mL | 1% |
| Para-Fluoro-Butyryl Fentanyl (p-FBF) | 75 ng/mL | 7% |
| Para-Fluorofentanyl | 10 ng/mL | 50% |
| Phenylacetyl Fentanyl | 7.5 ng/mL | 67% |
| Remifentanil | 100 ng/mL | 5% |
| THF Fentanyl (THFF) | 35 ng/mL | 14% |
| Thienyl Fentanyl | 15 ng/mL | 33% |
| Trans-DL-3-Methylfentanyl | 10 ng/mL | 50% |
| Valeryl Fentanyl | 50 ng/mL | 10% |
K252684 - Page 5 of 11
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The following non-structurally related compounds showed no interference at the concentrations listed:
| Common Drug | Concentration (ng/mL) | Common Drug | Concentration (ng/mL) |
| --- | --- | --- | --- |
| 1-(3-Trifluoromethylphenyl)-piperazine | 100,000 | Isotonitazene | 10,000 |
| 11-Hydroxy- 9-THC | 10,000 | Ketamine | 100,000 |
| 11-Nor-9-carboxy- 9-THC | 10,000 | Labetalol | 1,800,000 |
| 4-Bromo-2,5, Dimethoxyphenethylamine | 100,000 | Lamotrigine | 100,000 |
| 6-Acetylmorphine (6-MAM) | 100,000 | Lansoprazole | 100,000 |
| 7-Aminoclonazepam | 100,000 | L-Cotinine | 100,000 |
| 7-Aminoflunitrazepam | 100,000 | L-Erythromycin | 100,000 |
| 7-Aminonitrazepam | 10,000 | Levonorgestrel | 100,000 |
| Acetaminophen | 2,900,000 | Levorphanol | 100,000 |
| Acetylsalicylic Acid | 100,000 | Levothyroxine (L-Thyroxine) | 100,000 |
| AH-7921 (Doxylam) | 10,000 | Lisinopril | 100,000 |
| AH-8529 | 100,000 | L-Methamphetamine | 100,000 |
| AH-8533 | 100,000 | Loperamide | 100,000 |
| Albuterol | 100,000 | Loratadine | 100,000 |
| Allopurinol | 100,000 | Lorazepam | 100,000 |
| Alprazolam | 100,000 | Losartan | 100,000 |
| Aminopyrine (4-Dimethylaminoantipyrine) | 100,000 | Lurasidone | 10,000 |
| Amlodipine Besylate | 100,000 | Lysergic Acid Diethylamide (LSD) | 10,000 |
| Amoxicillin | 2,600,000 | Maprotiline | 100,000 |
| Ampicillin | 100,000 | Meperidine | 100,000 |
| Apixaban | 100,000 | Meprobamate | 100,000 |
| Apomorphine | 100,000 | Metformin | 2,900,000 |
| Aspartame | 100,000 | Methadone | 100,000 |
| Atenolol | 200,000 | Methapyrilene | 100,000 |
| Atorvastatin | 100,000 | Methylphenidate | 100,000 |
| Baclofen | 100,000 | Metonitazene | 10,000 |
| Benzocaine | 100,000 | Metoprolol | 550,000 |
| Benzoic Acid | 100,000 | Mitragynine | 100,000 |
| Benzoylecgonine | 100,000 | Morphine | 300,000 |
| Benzylpiperazine | 10,000 | Morphine-3-glucuronide | 10,000 |
| Brompheniramine | 100,000 | Nalidixic Acid | 100,000 |
| Buprenorphine | 100,000 | Naloxegol | 100,000 |
K252684 - Page 6 of 11
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K252684 - Page 7 of 11
| Common Drug | Concentration (ng/mL) | Common Drug | Concentration (ng/mL) |
| --- | --- | --- | --- |
| Bupropion | 100,000 | Naloxone | 100,000 |
| Caffeine | 1,200,000 | Naltrexone | 100,000 |
| Cannabidiol | 100,000 | Naproxen | 1,800,000 |
| Carbamazepine | 100,000 | N-Desmethylapentadol | 10,000 |
| Carisoprodol | 100,000 | Nifedipine | 100,000 |
| Carvedilol | 100,000 | Norbuprenorphine | 100,000 |
| Cetirizine | 100,000 | Norcodeine | 100,000 |
| Chloramphenicol | 100,000 | Nordiazepam | 100,000 |
| Chlorcyclizine | 100,000 | Norethindrone | 100,000 |
| Chlordiazepoxide | 100,000 | Norketamine | 100,000 |
| Chlorpheniramine | 100,000 | Normeperidine | 100,000 |
| Chlorpromazine | 15,000 | Normorphine | 10,000 |
| Cimetidine | 1,800,000 | Noroxycodone | 100,000 |
| Citalopram | 100,000 | Norpropoxyphene | 100,000 |
| Clofibrate | 100,000 | Norpseudoephedrine (Cathine) | 100,000 |
| Clomipramine | 100,000 | Noscapine | 100,000 |
| Clonazepam | 100,000 | Omeprazole | 100,000 |
| Clonidine | 100,000 | Oxazepam | 100,000 |
| Clopidogrel | 200,000 | Oxazepam Glucuronide | 1,000 |
| Codeine | 120,000 | Oxycodone | 100,000 |
| Cortisone | 100,000 | Oxymetazoline | 100,000 |
| Cyclobenzaprine | 100,000 | Oxymorphone | 100,000 |
| Cyclodextrin-r | 100,000 | Pantoprazole | 100,000 |
| Cyproheptadine | 100,000 | Papaverine | 100,000 |
| DL-Isoproterenol | 100,000 | Penicillin-G (Benzylpenicillin) | 100,000 |
| D-Amphetamine | 350,000 | Pentazocine | 35,000 |
| Demoxepam | 100,000 | Perospirone | 10,000 |
| Dextromethorphan | 100,000 | Phenelzine | 100,000 |
| Diclofenac | 200,000 | Pheniramine | 100,000 |
| Difunisal | 100,000 | Phentermine | 100,000 |
| Dihydrocodeine | 100,000 | Phenylephrine | 100,000 |
| Diphenhydramine | 100,000 | Phenylethylamine | 100,000 |
| Diphenylhydantoin (Phenytoin) | 100,000 | Pravastatin | 100,000 |
| D-Methamphetamine | 100,000 | Prednisone | 100,000 |
| Doxylamine | 100,000 | Promazine | 100,000 |
| D-Pseudoephedrine | 250,000 | Promethazine | 100,000 |
| Duloxetine | 150,000 | Propoxyphene | 10,000 |
{7}
| Common Drug | Concentration (ng/mL) | Common Drug | Concentration (ng/mL) |
| --- | --- | --- | --- |
| EDDP (Methadone metabolite) | 100,000 | Propranolol | 700,000 |
| Ephedrine | 100,000 | Propylhexedrine | 50,000 |
| Ergocalciferol | 100,000 | Pyrilamine | 150,000 |
| Escitalopram | 100,000 | Pyrogallol | 100,000 |
| Esomeprazole Mg hydrate | 250,000 | Ranitidine | 150,000 |
| Estrone | 100,000 | Rosuvastatin | 100,000 |
| Ethinyl Estradiol | 100,000 | Salicylic Acid | 1,000,000 |
| Famotidine | 1,000,000 | Sertindole | 10,000 |
| Fenfluramine | 100,000 | Sertraline | 30,000 |
| Fenofibrate | 100,000 | Simvastatin | 100,000 |
| Fexofenadine | 75,000 | Sodium Azide | 100,000 |
| Fluoxetine | 100,000 | Sulfamethazine | 100,000 |
| Fluticasone | 100,000 | Sulindac | 100,000 |
| Furosemide | 500,000 | Tamsulosin | 100,000 |
| Gabapentin | 4,500,000 | Temazepam | 100,000 |
| Gemfibrozil | 100,000 | Tetracycline | 100,000 |
| Gentisic Acid | 100,000 | Tetrahydrozoline | 100,000 |
| Glipizide | 100,000 | Thioridazine | 100,000 |
| Guaifenesin | 100,000 | Tianeptine | 100,000 |
| Heroin (Diacetylmorphine) | 100,000 | Tramadol | 450,000 |
| Hexobarbital | 10,000 | Trazodone | 10,000 |
| Hydralazine | 100,000 | Trifluoperazine | 100,000 |
| Hydrochlorothiazide | 150,000 | Venlafaxine | 100,000 |
| Hydrocodone | 100,000 | Xylazine | 100,000 |
| Hydrocortisone | 100,000 | Ziprasidone | 100,000 |
| Hydromorphone | 100,000 | Zolpidem | 100,000 |
| Ibuprofen | 2,700,000 | Zolpidem Tartrate | 100,000 |
| Insulin | 100,000 | | |
Positive interference was observed for the following compounds when tested at concentrations above those listed in the table above: Pentazocine and Fexofenadine.
Negative interference was observed for the following compounds when tested at concentrations above those listed in the table above: Baclofen, Chlorpromazine, Fexofenadine Propranolol, Sertraline, Potassium Chloride, Pyridoxine. The following Norfentanyl analogs were also observed to cause negative interference above those listed in the table below: Carfentanil, MT-45, 4-Methoxybutyryl Fentanyl, and U-4770.
K252684 - Page 8 of 11
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The following non-structurally related compounds showed interference and/or cross reactivity at the concentrations listed:
| Non-Fentanyl Cross Reactive Compounds | | |
| --- | --- | --- |
| Compound | Concentration | % Cross Reactivity |
| Fluphenazine | Positive at 50,000 ng/mL | < 1% |
| Perphenazine | Positive at 75,000 ng/mL | < 1% |
| Quinidine | Positive at 25,000 ng/mL | < 1% |
| Quinine | Positive at 50,000 ng/mL | < 1% |
| Risperidone | Positive at 2,500 ng/mL | < 1% |
| Risperidone Metabolite: 9-Hydroxyrisperidone | Positive at 2,500 ng/mL | < 1% |
| Non-reactive Fentanyl/Norfentanyl analogs | | |
| --- | --- | --- |
| Compound | Concentration | % Cross Reactivity |
| Carfentanil | Negative at 500 ng/mL | N/A |
| Despropionylfentanyl (4-ANPP) | Negative at 1,000 ng/mL | N/A |
| MT-45 | Negative at 3,500 ng/mL | N/A |
| 4-Methoxybutyryl Fentanyl | Negative at 5,000 ng/mL | N/A |
| Norcarfentanil | Negative at 1,000 ng/mL | N/A |
| Sufentanil | Negative at 1,000 ng/mL | N/A |
| U-47700 | Negative at 5,000 ng/mL | N/A |
pH study: To evaluate the effect of pH value on the test results, urine controls at 50% and 150% of the cutoff value was used. Each control level was adjusted by either 6N NaOH solution or 6N HCl to pH levels of 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0 and 9.0. A total of 5 replicates per sample were tested.
Specific gravity study: To evaluate the effect of specific gravity, urine controls at 50% and 150% of the cutoff values were mixed and pooled as needed to obtain specific gravities of 1.001, 1.004, 1.010, 1.014, 1.020, 1.025, and 1.030. A total of 5 replicates per sample were tested.
The results demonstrated that pH and specific gravity do not affect the results from the device at the conditions tested.
4. Assay Reportable Range:
Not applicable because this device is intended for qualitative use only for detection of norfentanyl in human urine at concentrations above 5 ng/mL.
5. Traceability, Stability, Expected Values (Controls, Calibrators, or Methods):
All drug calibrators of the device are traceable to available commercial reference materials.
6. Detection Limit:
Characterization of how the device performs at low concentrations appears in the precision section, VII.A.1, above.
K252684 - Page 9 of 11
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7. Assay Cut-Off:
Characterization of how the device performs analytically around the claimed cutoff concentration appears in the precision section, VII.A.1, above.
B Comparison Studies:
1. Method Comparison with Predicate Device:
The sponsor performed a method comparison study comparing the performance of the test strips to the LC/MS reference method. A total of 40 samples that did not contain norfentanyl (or fentanyl) and 47 samples containing varying concentrations of norfentanyl (and fentanyl), including 7 below the test cutoff, were assayed on 3 lots using a different operator for each lot and run in a random order over 3 days. The results are summarized below:
| Fentanyl Test (nFEN) (5 ng/mL Cutoff) | Concentration by LC-MS/MS (ng/mL) | | | | | |
| --- | --- | --- | --- | --- | --- | --- |
| | | No Drug Present | Low Negative (<50% of cutoff) | Near Cutoff Negative (50% - 100% of cutoff) | Near Cutoff Positive (100% - 150% of cutoff) | True Positive (>150% of cutoff) |
| Lot 1 | Positive | 0 | 0 | 3 | 4 | 36 |
| | Negative | 40 | 3 | 1 | 0 | 0 |
| Lot 2 | Positive | 0 | 0 | 3 | 4 | 36 |
| | Negative | 40 | 3 | 1 | 0 | 0 |
| Lot 3 | Positive | 0 | 0 | 3 | 4 | 36 |
| | Negative | 40 | 3 | 1 | 0 | 0 |
Three near cutoff negative clinical samples produced positive discordant results with all three strip lots. Discordant results are summarized below:
| Fentanyl Test (nFEN) Result | LC-MS/MS Norfentanyl (ng/mL) |
| --- | --- |
| Positive (+) | 4.76 |
| Positive (+) | 3.86 |
| Positive (+) | 3.34 |
2. Matrix Comparison:
Not applicable. This device is for use with urine samples only.
C Clinical Studies:
1. Clinical Sensitivity:
Not applicable.
2. Clinical Specificity:
Not applicable.
K252684 - Page 10 of 11
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3. Other Clinical Supportive Data (When 1. and 2. Are Not Applicable):
Not applicable.
D. Clinical Cut-Off:
Not applicable.
E. Expected Values/Reference Range:
Not applicable.
VIII. Proposed Labeling:
The labeling does support the finding of substantial equivalence for this device.
IX. Conclusion:
The submitted information in this premarket notification is complete and does support a substantial equivalence decision.
K252684 - Page 11 of 11
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Learn the FDA Browser
Two short videos show you everything — or skip straight to the written tutorial if you'd rather read. You can reopen this any time from the Tutorial button in the top bar.
Part 1 — Search, results, and everyday workflows 16 min
Part 2 — Embeddings: the galaxy map 3 min
1. Search: exact and fuzzy
Type a phrase like "coronary artery calcification" into the search box. You get two kinds of results. Exact results match the literal phrase — prefix searches work ("coronary artery calcificati") but suffix searches do not. Fuzzy results match on the meaning and intent of your phrase rather than the exact words, and are sorted by relevance score. Hover over the Exact or Fuzzy badge on any row to see exactly why it matched.
Use the checkboxes above the results to narrow: SaMD keeps only software-only devices, AI / ML keeps only devices with AI.
Exact vs. fuzzy search: what's the difference?
Exact matches on the literal phrase (prefix search works, suffix does not). Fuzzy matches on the meaning and intent of the phrase rather than the exact words. Hover over the badge on any row to see why it matched.
You search "coronary artery calcification" and want only software devices with AI. What two filters do you apply?
Narrow by SaMD (software-only devices), then narrow by AI/ML (devices with AI).
2. The results table
Scroll right in the results table. The intended use is extracted for you — no need to open the PDF. The device story gives a high-level snapshot of what the device does and how it's used. The AI Performance sub-table shows each output name, acceptance criteria, observed values, and development/test dataset descriptions — the same format Innolitics uses for regulatory strategy outputs, and the fastest high-level fingerprint of an AI device. It is AI-generated but has been very reliable in practice.
Where do you find a device's intended use without opening the PDF?
Scroll right in the search results table. The intended use column is extracted for you; no need to dig into the 510(k) summary PDF.
What does the AI Performance sub-table show, and why is it useful?
Output name, acceptance criteria, observed values, development dataset description, and test dataset description. It's the same format we use for regulatory strategy output and Fast 510(k) input, and the fastest high-level fingerprint of an AI device. AI-generated but reliable in practice.
3. Judging fuzzy relevance
Fuzzy results trail off in relevance as you scroll. Use three signals to decide how far down to go: the fuzzy badge explanations, the intended use column, and whether your target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, you're past the relevant zone. A top hit with a low score (~0.4) and a stretched explanation is a hint the closest predicates are far away — the project may be headed for De Novo. Note the fuzzy search is a pattern match: it doesn't handle negation ("not") well, and hardware devices can appear — filter by SaMD/AI ML to cut them.
How do you judge how far down fuzzy search results to go?
Use the relevancy signals: the fuzzy badge explanations, the intended use column, and whether the target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, results are trailing off in relevancy.
4. Device detail page: chat and citations
Click a device name to open its detail page: device facts on the left, a chat window on the right. Ask something like "Describe the training data". The answer carries little citation bubbles — click one to jump to the highlighted passage in the source PDF, so you can verify every AI answer against the document. There's also a Download PDF button for sharing.
How do you verify an AI chat answer on the device detail page?
Click the citation bubbles to jump to the relevant highlight in the source document.
Reading rule for every project: how many summaries do you read in full?
At least the three most relevant 510(k) or De Novo summaries, in full. After that, use targeted chat questions to confirm your memory quickly. The tool supports this professional habit — it doesn't replace it.
5. Side-by-side comparison
Select multiple rows in the results table (aim for under ~10), then open the PDF Viewer tab. Ask one question — it goes to all selected devices in parallel, each with citations. This is the fastest way to compare and contrast devices: training data, PCCP scope, how they handled adding new scanners, and so on.
What does the side-by-side PDF viewer mode do?
Select multiple devices, open the PDF viewer tab, and ask one question (e.g., "Describe the training data"). It queries all selected devices simultaneously with citations, so you can compare and contrast quickly.
6. Collections
With rows selected, go to the Collections tab and create a labeled collection (e.g., "Cobb Angle Project"). Reload that selection any time — before a client call, pull up the collection and ask questions across all of its devices at once.
How do you save a set of selected devices for later use?
Select the rows, go to the Collections tab, and create a labeled collection (e.g., "Cobb Angle Project"). You can reload the selection anytime and carry it into the PDF viewer and other tabs that support selections.
7. Product codes and the regulations tree
Click a product code in the results to jump to it in the regulations tree — identification text, sibling product codes, and devices you can open in a PDF viewer on the right. Click a regulation number to see its identification, special controls, and related product codes. You can also search by product code or regulation number at the top of the tree. Always read the special controls if any exist for your device — it broadens your search and sharpens pre-kickoff research.
What can you do from the regulations tree view?
Browse product codes and regulation numbers, read the identification text and special controls, browse sibling product codes, open device PDFs on the right, and search by product code or regulation number at the top of the tree.
8. Chart view
Click Show Chart and segment by regulation number (or product code) to see which regulations dominate your result set. Clicking a regulation takes you into the regulations tree. Great for spotting that most matches are, say, hardware laparoscopic devices — a cue to go back and filter.
How do you see which regulations dominate a search result set?
Click "Show Chart" and segment by Regulation Number. Clicking a regulation takes you to the regulations tree.
9. The predicate graph
Open the Predicates tab for a family-tree view of predicate relationships. Click a node to trace its parents and children; selections from search carry over pre-selected. Commonly predicated devices are worth reading — a lot of people predicated them for a reason. The visual lineage is also handy on client calls, e.g. to show how a predicate family evolved and justify why your predicate still holds.
In the predicate graph, why are commonly predicated devices worth reading?
A lot of people predicated them for a reason. Clicking a node traces parents and children, and selections from search carry over pre-selected.
10. Embeddings: the galaxy map
The Embeddings tab plots every matching document in a 2-D "galaxy map" where semantically similar devices cluster together. Hover or click clusters to explore, and let AI label the clusters for you. Embeddings beat product codes for grouping: two devices can carry different product codes (LLZ vs. QIH) yet do the same thing — the embedding captures the meaning of the intended use and device story. This is also exactly how retrieval-augmented generation (RAG) works under the hood, and it makes a great visual on client calls.
Try it yourself
Head to the search page and work through a few of these AI/ML fuzzy searches to build intuition: perivascular fat on CT · aortic valve calcification opportunistic screening on noncontrast CT · breast cancer prediction on digital pathology slides · autism detection · gestational age prediction · a hearing aid that can also detect a pulse · foundation model based analysis of ECG · large language models · penetration test. Watch how the relevance scores, intended use, and AI Performance tables tell you when results stop being meaningful.