The Phencyclidine Enzyme Immunoassay is a homogeneous enzyme immunoassay with a 25 ng/mL cutoff. The assay is intended for use in the qualitative and semi-quantitative analyses of phencyclidine (PCP) in human urine.

The Phencyclidine Enzyme Immunoassay provides only a preliminary analytical test result. A more specific alternative chemical method must be used to obtain a confirmed analytical result. Gas chromatography/mass spectrometry (GC/MS) is the preferred confirmatory method. Clinical consideration and professional judgement should be applied to any drug-ofabuse test result, particularly when preliminary positive results are used.

Device Description

LZI's Phencyclidine Enzyme Immunoassay is a ready-to-use, liguid reagent, homogeneous enzyme immunoassay. The assay uses specific antibody that can detect phencyclidine in human urine with minimal cross-reactivity to various phencyclidine-related compounds and/or common drugs.

The assay is based on competition between phencyclidine labeled with enzyme glucose-6phosphate dehydrogenase (G6PDH), and free drug from the urine sample for a fixed amount of specific antibody. In the absence of free drug from the urine sample the specific antibody binds to the drug labeled with G6PDH enzyme causing a decrease in enzyme activity. The G6PDH enzyme activity is determined spectrophotometrically at 340 nm by measuring its ability to covert nicotinamide adenine dinucleotide (NAD) to NADH.

AI/ML Overview

Here's an analysis of the acceptance criteria and study information for the Lin-Zhi International, Inc.' Phencyclidine Enzyme Immunoassay, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

The submission generally compares the LZI device's performance to a predicate device (DRI's PCP EIA) rather than explicitly stating pre-defined acceptance criteria with numerical targets. However, based on the comparative nature of the study, the "acceptance criteria" can be inferred to be performance that is comparable to or better than the predicate.

Feature	Predicate Device (DRI's PCP EIA) Performance (Inferred Acceptance Criteria)	LZI's Phencyclidine EIA Reported Device Performance
Within Run Precision (Qualitative):	Low % CV (e.g., 0.3-0.8%)	Low % CV (e.g., 0.21-0.50%)
Negative	Mean Rate 315, % CV 0.8	Mean Rate 168.0, % CV 0.41
20/18 ng/mL	Mean Rate 378, % CV 0.6	Mean Rate 238.6, % CV 0.49
25 ng/mL (Cutoff)	Mean Rate 400, % CV 0.5	Mean Rate 264.6, % CV 0.45
35/32 ng/mL	Mean Rate 426, % CV 0.3	Mean Rate 282.8, % CV 0.50
100 ng/mL	Mean Rate 502, % CV 0.4	Mean Rate 341.2, % CV 0.21
Within Run Precision (Semi-quantitative):	No data available	Low % CV (e.g., 1.50-1.71%)
18 ng/mL	N/A	Mean Recovery 17.4, % CV 1.54
25 ng/mL	N/A	Mean Recovery 24.7, % CV 1.50
32 ng/mL	N/A	Mean Recovery 31.6, % CV 1.71
Run-To-Run Precision (Qualitative):	Low % CV (e.g., 0.6-1.0%)	Low % CV (e.g., 0.23-0.54%)
Negative	Mean Rate 316, % CV 0.6	Mean Rate 168.0, % CV 0.54
20/18 ng/mL	Mean Rate 380, % CV 0.9	Mean Rate 238.8, % CV 0.23
25 ng/mL (Cutoff)	Mean Rate 400, % CV 0.6	Mean Rate 264.6, % CV 0.30
35/32 ng/mL	Mean Rate 425, % CV 1.0	Mean Rate 284.1, % CV 0.31
100 ng/mL	Mean Rate 501, % CV 0.9	Mean Rate 340.1, % CV 0.32
Run-To-Run Precision (Semi-quantitative):	No data available	Low % CV (e.g., 1.91-2.49%)
18 ng/mL	N/A	Mean Recovery 17.1, % CV 2.49
25 ng/mL	N/A	Mean Recovery 24.3, % CV 2.26
32 ng/mL	N/A	Mean Recovery 31.4, % CV 1.91
Sensitivity	5 ng/mL	1 ng/mL (This is better than the predicate)
Accuracy (vs. Commercially available EIA)	100% Sensitivity, 100% Specificity	100% Sensitivity, 100% Specificity (vs. DRI's PCP EIA)
Analytical Recovery (Qualitative)	No data available	100% accurate of positive vs. negative tests
Analytical Recovery (Semi-quantitative)	No data available	Quantitates within ±10% of nominal concentration (8-80 ng/mL)96.1% recovery at 18 ng/mL97.8% recovery at 32 ng/mL
Specificity	Comparable to predicate device (See attached DRI PCP EIA package insert)	Comparable to the predicate device.

2. Sample Size Used for the Test Set and Data Provenance

The document does not explicitly state the sample size used for the test set. For precision studies, it lists mean rates, SD, and %CV, which implies multiple measurements were taken for each concentration level. However, the exact number of replicates or individual samples is not provided.

The data provenance is not specified (e.g., country of origin). It solely states "human urine," but for regulated submissions, more detail is typically expected. The studies appear to be retrospective, as they involve testing the new device against known concentrations or against a predicate device using existing methods.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts

This type of immunoassay (drug screening) does not typically involve human expert interpretation of results to establish ground truth in the same way as, for example, image analysis. The "ground truth" for the test set is established by:

Known concentrations: For precision studies, specific concentrations (e.g., 18, 25, 32, 100 ng/mL phencyclidine) are prepared, representing the "ground truth."
Referenced confirmatory methods: For accuracy studies, the predicate device and implicitly, confirmatory methods like Gas Chromatography/Mass Spectrometry (GC/MS) are used to establish ground truth.
"Positive vs. Negative tests": For qualitative analytical recovery, the ground truth is simply whether the sample is truly positive or negative for phencyclidine.

Therefore, the concept of "experts" to establish ground truth with specific qualifications (like radiologists) does not directly apply here. The expertise is in the analytical methods and preparation of accurate controls.

4. Adjudication Method for the Test Set

Adjudication methods (like 2+1, 3+1) are typically used in studies where multiple human readers independently assess data and their discrepancies need to be resolved. This is not applicable to the analytical performance studies of this immunoassay device. The results are quantitative measurements, and accuracy is determined by comparison to known values or validated reference methods, not subjective expert consensus.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, If So, What Was the Effect Size of How Much Human Readers Improve with AI vs. Without AI Assistance

No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This device is an in vitro diagnostic immunoassay, not a device intended for human interpretation or AI assistance in clinical decision-making. Therefore, the concept of human readers improving with or without AI assistance is irrelevant to this submission.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done

Yes, the performance presented for LZI's Phencyclidine Enzyme Immunoassay is entirely standalone (algorithm/device-only performance). The assay generates results automatically based on spectrophotometric measurements and chemical reactions; there is no human in the loop for interpreting the primary analytical result provided by the device. The device provides a preliminary analytical test result that then requires professional judgment and possibly confirmatory methods.

7. The Type of Ground Truth Used (Expert Consensus, Pathology, Outcomes Data, etc.)

The ground truth used for the performance studies includes:

Known concentrations of phencyclidine: For precision and semi-quantitative analytical recovery.
Results from a legally marketed predicate device (DRI's PCP EIA): For accuracy and specificity comparisons. Ultimately, the predicate device would itself have been validated against gold standard chemical methods.
Implied reference to Gas Chromatography/Mass Spectrometry (GC/MS) as the preferred confirmatory method: Although not explicitly stated as the direct ground truth for all presented studies, the "Indications for Use Statement" clearly positions it as the gold standard for confirmation.

8. The Sample Size for the Training Set

The document does not specify a "training set" in the context of device development. For an immunoassay, the development process involves reagent formulation and optimization, not machine learning model training with specific data sets. The data presented are for the analytical validation of the final device.

9. How the Ground Truth for the Training Set Was Established

As no "training set" for an algorithm or model is relevant to this immunoassay, this question is not applicable. The development of such assays relies on biochemical principles, calibration with known standards, and optimization without a "training set" in the AI sense.

Summary

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MAY 1 0 2002

510(k) Summary of Safety and Effectiveness

This summary of 510(k) safety and effectiveness information is being submitted in accordance with the requirements of SMDA 1990 and 21 CFR 807.92.

Introduction

According to the requirements of 21 CFR 807.92, the following information provides sufficient detail to understand the basis for a determination of substantial equivalence.

Submitter name. Address, and Contact

Lin-Zhi International, Inc. 2391 Zanker Road, Suite 340 San Jose, CA 95131 Phone: (408) 944-0360 (408) 944-0358 Fax:

Chiu Chin Chang, Ph.D. Contact: VP. R&D

Device Name and Classification

Classification Name:	Phencyclidine test system, Class II, LCM (91 Toxicology)
Common Name:	Homogeneous enzyme immunoassay for the determination ofphencyclidine levels in urine.
Proprietary Name:	None

Legally Marketed Predicate Device(s)

Lin-Zhi International, Inc.' Phencyclidine Enzyme Immunoassay is substantially equivalent to the Phencyclidine Enzyme Immunoassay by Diagnostic Reagents Inc. (now Microgenics, Inc.), cleared under premarket notification K935320.

LZI's Phencyclidine Enzyme Immunoassay is identical or similar to its predicate in terms of intended use, method principle, device components, and clinical performance.

Device Description

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Intended Use

Comparison to Predicate Device

LZI's Phencyclidine Enzyme Immunoassay is substantially equivalent to other products in commercially distribution intended for similar use. Most notably it is substantially equivalent to the currently, commercially marketed DRI Phencyclidine Enzyme Immunoassay (K935320),

The following table compares LZI's Phencyclidine Enzyme Immunoassay with the predicate device, DRI's Phencyclidine Enzyme Immunoassay. Specific data on the performance of the test have been incorporated into the proposed product insert (Attachment A). Product inserts for the predicate device and two other commercial products of similar intended use are provided in the Attachment C.

Similarities:

Both assays are for qualitative and semi-quantitative determination of PCP in � human urine.
Both assays use the same method principle, and device components. ●
Both assay use 25 ng/mL as cutoff level per recommendations of The Substance . Abuse and Metal Health Services Administration (SAMHSA).

Differences:

Five (5) calibrators are available for semi-quantitative analysis. DRI's Phencyclidine Enzyme Immunoassay uses 3 calibrators previously. Two additional calibrators are also available commercially now.

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(Comparison to Predicate Device, continued)

Performance Characteristics

100 M Fr

Feature	DRI'sPCP EIA				LZI'sPhencyclidine EIA
Within Run Precision:
Qualitative:		Mean Rate	SD	% CV		Mean Rate	SD	% CV
	Negative	315	-	0.8	Negative	168.0	0.68	0.41
	20 ng/mL	378	-	0.6	18 ng/mL	238.6	1.16	0.49
	25 ng/mL	400	-	0.5	25 ng/mL	264.6	1.19	0.45
	35 ng/mL	426	-	0.3	32 ng/mL	282.8	1.42	0.50
	100 ng/mL	502	-	0.4	100 ng/mL	341.2	0.73	0.21
Semi-quantitative:	No data available				Mean Recovery
					18 ng/mL	17.4	0.27	1.54
					25 ng/mL	24.7	0.37	1.50
					32 ng/mL	31.6	0.54	1.71
Run-To-Run Precision:
Qualitative:		Mean Rate	SD	% CV		Mean Rate	SD	% CV
	Negative	316	-	0.6	Negative	168.0	0.90	0.54
	20 ng/mL	380	-	0.9	18 ng/mL	238.8	0.55	0.23
	25 ng/mL	400	-	0.6	25 ng/mL	264.6	0.79	0.30
	35 ng/mL	425	-	1.0	32 ng/mL	284.1	0.87	0.31
	100 ng/mL	501	-	0.9	100 ng/mL	340.1	1.07	0.32
Semi-quantitative:	No data available					Mean Recovery
					18 ng/mL	17.1	0.43	2.49
					25 ng/mL	24.3	0.55	2.26
					32 ng/mL	31.4	0.60	1.91
Sensitivity:	5 ng/mL				1 ng/mL
Accuracy:	Vs. a commercially available EIA				Vs. DRI's PCP EIA
Sensitivity:	100%				100%
Specificity:	100%				100%
Analytical Recovery:
	Qualitative: No data available				100 % accurate of positive vs. negative tests
	Semi-quantitative: No data available				Quantitates within ±10% of the nominal
					concentration between 8 ng/mL and 80 ng/mL.
					96.1% recovery at 18 ng/mL level (Cutoff - 25%)
					97.8% recovery at 32 ng/mL level (Cutoff + 25%)
Specificity:		See attached DRI PCP EIA packageinsert				Comparable to the predicate device.

progr

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Conclusion

LZI's Phencyclidine Enzyme Immunoassay was evaluated for several performance characteristics including precision, sensitivity, accuracy, analytical recovery, and specificity. All the studies showed acceptable results when compared to the predicate device.

We trust the information provided in this Premarket Notification [510(k)] submission will support a determination of substantial equivalence of the LZI's Phencyclidine Enzyme Immunoassay to other PCP test systems currently marketed in the United States.

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Image /page/4/Picture/1 description: The image is a black and white logo for the U.S. Department of Health & Human Services. The logo features the department's name in a circular arrangement around a symbol. The symbol consists of three stylized human profiles facing right, with flowing lines suggesting movement or connection.

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

MAY 1 0 2002

Chiu Chin Chang, Ph.D. VP. R&D Lin-Zhi International, Inc. 2391 Zanker Road, Suite 340 San Jose, CA 95131-1124

Re: K020254

Trade/Device Name: Phencyclidine Enzyme Immunoassay Regulatory Class: Class II Product Code: LCM Dated: April 15, 2002 Received: April 24, 2002

Dear Dr. Chang:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

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Page 2 -

This letter will allow you to begin marketing your device as described in your 510(k) premarket This leater inn and it your ding of substantial equivalence of your device to a legally marketed noutication. This in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and 1 additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4588. Additionally, for questions on the promotion and advertising of your device, (201) 594-42 contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small miorination on Judi resistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its internet address "http://www.fda.gov/cdrh/dsma/dsmamain.html".

Sincerely yours,

Steven Butman

Steven I. Gutman, M.D., M.B.A. Director Division of Clinical Laboratory-Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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Premarket Notification

Indications for Use Statement

510 (K) Number (if known): _ KQ2003SY

Device Name: Phencyclidine Enzyme Immunoassay

Indications for Use:

Jean Cooper

(Division Sign-Off)

vision of Clinical Laboratory Devices 510(k) Number

Concurrence of CDRH, Office of Device Evaluation (ODE)

Prescription Use (Per 21 CFR 801.109) OR

Over-The-Counter Use

(Optional Format 1-2-96)

Regulation Number and Section

N/A