← Product Code [DJR](/submissions/TX/subpart-d%E2%80%94clinical-toxicology-test-systems/DJR) · K192433

# LZI Methadone II Enzyme Immunoassay (K192433)

_Lin-Zhi International, Inc. · DJR · Oct 4, 2019 · Clinical Toxicology · SESE_

**Canonical URL:** https://fda.innolitics.com/submissions/TX/subpart-d%E2%80%94clinical-toxicology-test-systems/DJR/K192433

## Device Facts

- **Applicant:** Lin-Zhi International, Inc.
- **Product Code:** [DJR](/submissions/TX/subpart-d%E2%80%94clinical-toxicology-test-systems/DJR.md)
- **Decision Date:** Oct 4, 2019
- **Decision:** SESE
- **Submission Type:** Traditional
- **Regulation:** 21 CFR 862.3620
- **Device Class:** Class 2
- **Review Panel:** Clinical Toxicology

## Indications for Use

The LZI Methadone II Enzyme Immunoassay is an in vitro diagnostic test intended for the qualitative and semi-quantitative determination of methadone in human urine. The cutoff for both the qualitative and semi-quantitative modes of the assay is 300 ng/mL for methadone. The assay is designed for prescription use on automated clinical chemistry analyzers. The semi-quantitative mode is for purposes of (1) enabling laboratories to determine an appropriate dilution of the specimen for confirmation by a confirmatory method such as gas or liquid chromatography/mass spectrometry (GC/MS or LC/MS) or (2) permitting laboratories to establish quality control procedures. The assay provides only a preliminary analytical result. A more specific alternative analytical chemistry method must be used in order to obtain a confirmed analytical result. Gas or liquid chromatography/mass spectrometry (GC/MS or LC/MS) is the preferred confirmatory method. 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

LZI Methadone II Enzyme Immunoassay is a homogeneous enzyme immunoassay for urine methadone detection. Input: human urine sample. Principle: competitive binding between sample methadone and methadone-labeled G6PDH enzyme for fixed antibody; free methadone displaces labeled enzyme, increasing enzyme activity. Output: absorbance change measured spectrophotometrically at 340 nm, correlating to methadone concentration. Used in clinical laboratories on automated chemistry analyzers by trained personnel. Provides preliminary screening results; requires confirmatory testing via GC/MS or LC/MS for clinical decision-making. Assists in identifying methadone presence for clinical or laboratory quality control purposes.

## Clinical Evidence

Bench testing included precision (NCCLS-EP5, 88 runs), linearity (100-1000 ng/mL), cross-reactivity, and interference studies. Clinical accuracy evaluated using 94 unaltered clinical samples compared against LC/MS. Semi-quantitative accuracy showed 97.8% positive agreement and 97.9% negative agreement. Qualitative accuracy showed 97.8% positive agreement and 97.9% negative agreement.

## Technological Characteristics

Homogeneous enzyme immunoassay. Reagents: R1 (mouse monoclonal anti-methadone antibody, G6P, NAD, stabilizers, 0.09% sodium azide); R2 (methadone-labeled G6PDH, buffer, 0.09% sodium azide). Sensing: spectrophotometric absorbance at 340 nm. Form factor: liquid reagents for automated clinical chemistry analyzers. Storage: 2-8°C.

## Regulatory Identification

A methadone test system is a device intended to measure methadone, an addictive narcotic pain-relieving drug, in serum and urine. Measurements obtained by this device are used in the diagnosis and treatment of methadone use or overdose and to determine compliance with regulations in methadone maintenance treatment.

## Special Controls

*Classification.* Class II (special controls). A methadone 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).

## Submission Summary (Full Text)

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# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION
## TRIAGE-QUICK REVIEW DECISION SUMMARY

510(k) Number: k192433

This 510(k) was reviewed under OIR’s Triage-Quick Review Program. This program represents an internal workload management tool intended to reduce internal FDA review resources for 510(k) applications that are of good quality upon receipt by FDA.

The information in the 510(k) is complete and supports a substantial equivalence (SE) determination. Please refer to the applicant’s 510(k) summary for a summary of the information that supports this SE determination.

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**Source:** [https://fda.innolitics.com/submissions/TX/subpart-d%E2%80%94clinical-toxicology-test-systems/DJR/K192433](https://fda.innolitics.com/submissions/TX/subpart-d%E2%80%94clinical-toxicology-test-systems/DJR/K192433)

**Published by [Innolitics](https://innolitics.com)** — a medical-device software consultancy. We help companies design, build, and clear FDA-regulated software and AI/ML devices. If you're preparing [a 510(k)](https://innolitics.com/services/510ks/), [a De Novo](https://innolitics.com/services/regulatory/), [a SaMD](https://innolitics.com/services/end-to-end-samd/), [an AI/ML medical device](https://innolitics.com/services/medical-imaging-ai-development/), or [an FDA regulatory strategy](https://innolitics.com/services/regulatory/), [get in touch](https://innolitics.com/contact).

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