LZI Fentanyl III Enzyme Immunoassay

K251634 · Lin-Zhi International, Inc. · DJG · Jun 18, 2025 · Clinical Toxicology

Device Facts

• Record ID: K251634
• Device Name: LZI Fentanyl III Enzyme Immunoassay
• Applicant: Lin-Zhi International, Inc.
• Product Code: DJG · Clinical Toxicology
• Decision Date: Jun 18, 2025
• Decision: SESE
• Submission Type: Special
• Regulation: 21 CFR 862.3650
• Device Class: Class 2

Indications for Use

The LZI Fentanyl III Enzyme Immunoassay is intended for the qualitative determination of fentanyl in human urine at the cutoff value of 1 ng/mL when calibrated against fentanyl. The assay is designed for prescription use with a number of automated clinical chemistry analyzers. The assay provides only a preliminary analytical result. A more specific alternative chemical method (e.g., gas or liquid chromatography and mass spectrometry) must be used in order to obtain a confirmed analytical result. Clinical consideration and professional judgment should be exercised with any drug of abuse test result, particularly when the preliminary test result is positive.

Device Story

The LZI Fentanyl III Enzyme Immunoassay is a homogeneous enzyme immunoassay for the qualitative detection of fentanyl in human urine. It utilizes a competitive binding principle where fentanyl in the sample competes with fentanyl-labeled glucose-6-phosphate dehydrogenase (G6PDH) for a fixed amount of anti-fentanyl antibody. In the absence of fentanyl, the antibody binds the labeled conjugate, inhibiting enzyme activity. When fentanyl is present, it binds the antibody, leaving the labeled conjugate free to exhibit maximal enzyme activity. The active enzyme converts NAD to NADH, producing an absorbance change measured spectrophotometrically at 340 nm. The device is intended for use in clinical laboratories by trained personnel on automated clinical chemistry analyzers. Results are preliminary and require confirmation by a more specific method like LC/MS or GC/MS. The assay aids healthcare providers in identifying potential fentanyl use, supporting clinical decision-making regarding patient management and substance abuse screening.

Clinical Evidence

No clinical data provided. Substantial equivalence supported by design control activities, risk analysis, and verification/validation testing of the modified assay parameters.

Technological Characteristics

Homogeneous enzyme immunoassay; liquid, ready-to-use reagents (R1: mouse monoclonal anti-fentanyl antibody, G6P, NAD; R2: fentanyl-labeled G6PDH). Detection via spectrophotometry at 340 nm. Designed for automated clinical chemistry analyzers. Preservative: 0.09% sodium azide. Storage: 2-8 °C.

Indications for Use

Indicated for the qualitative determination of fentanyl in human urine at a 1 ng/mL cutoff. For prescription use in clinical laboratories using automated clinical chemistry analyzers. Requires confirmation by specific alternative chemical methods (e.g., LC/MS or GC/MS).

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

• LZI Fentanyl III Enzyme Immunoassay (K251634)

Submission Summary (Full Text)

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FDA U.S. FOOD & DRUG ADMINISTRATION

# SPECIAL 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY

## I Background Information:

A 510(k) Number

K251634

B Applicant

Lin-Zhi International, Inc.

C Proprietary and Established Names

LZI Fentanyl III Enzyme Immunoassay

D Regulatory Information

| Product Code(s) | Classification | Regulation Section | Panel |
| --- | --- | --- | --- |
| DJG | Class II | 21 CFR 862.3650 - Opiate Test System | TX - Clinical Toxicology |

## II Review Summary:

This 510(k) submission contains information/data on modifications made to the submitter's own Class II device requiring 510(k). The following items are present and acceptable.

1. The name and 510(k) number of the SUBMITTER'S previously cleared device. (For a preamendments device, a statement to this effect has been provided.)
2. Submitter's statement that the INDICATIONS FOR USE/INTENDED USE of the modified device as described in its labeling HAS NOT CHANGED along with the proposed labeling which includes instructions for use, package labeling, and, if available, advertisements or promotional materials (labeling changes are permitted as long as they do not affect the intended use).
3. A description of the device MODIFICATION(S), including clearly labeled diagrams, engineering drawings, photographs, user's and/or service manuals in sufficient detail to demonstrate that the FUNDAMENTAL SCIENTIFIC TECHNOLOGY of the modified device has not changed. These changes include: 1) the analyte detected is changed from norfentanyl to fentanyl, 2) cutoff is changed from 5 ng/mL to 1 ng/mL, 3) control levels are

Food and Drug Administration

10903 New Hampshire Avenue

Silver Spring, MD 20993-0002

www.fda.gov

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changed from 3.75 ng/mL and 6.25 ng/mL to 0.5 ng/mL and 1.5 ng/mL, and 4) application Volume are changed from R1=120 μL and R2=45 μ to R1=65 μL and R2=25 μL.

4. Comparison Information (i.e., similarities and differences) to the submitter's legally marketed predicate device including, labeling, intended use, and physical characteristics.

5. A Design Control Activities Summary which includes:

a) Identification of Risk Analysis method(s) used to assess the impact of the modification on the device and its components, and the results of the analysis.

b) Based on the Risk Analysis, an identification of the verification and/or validation activities required, including methods or tests used and acceptance criteria to be applied.

The labeling for this modified subject device has been reviewed to verify that the indication/intended use for the device is unaffected by the modification. In addition, the submitter's description of the particular modification(s) and the comparative information between the modified and unmodified devices demonstrate that the fundamental scientific technology has not changed. The submitter has provided the design control information as specified in The New 510(k) Paradigm and on this basis, I recommend the device be determined substantially equivalent to the previously cleared (or their preamendment) device.

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