(115 days)
The Immunalysis Barbiturates Urine Enzyme Immunoassay is a homogeneous enzyme immunoassay with a cutoff of 200 ng/mL. The assay is intended for use in laboratories for the qualitative and semi-quantitative analysis of Barbiturates in human urine with automated clinical chemistry analyzers. This assay is calibrated against Secobarbital. This in vitro diagnostic device is for prescription use only.
The semi-quantitative mode is for purposes of enabling laboratories to determine an appropriate dilution of the specimen for confirmation by a confirmatory method such as Gas Chromatography/ Mass Spectrometry (GC-MS) or Liquid Chromatography/ Tandem Mass Spectrometry (LC-MS/MS) or permitting laboratories to establish quality control procedures.
The Immunalysis Barbiturates Urine Enzyme Immunoassay provides only a preliminary analytical test result. A more specific alternate chemical method must be used in order to obtain a confirmed analytical result. GC-MS or LC-MS/MS is the preferred confirmatory method. Clinical consideration and professional judgment should be applied to any drug of abuse test result, particularly when preliminary positive results are used.
Immunalysis Multi-Drug Calibrators:
The Immunalysis Multi-Drug Calibrators are intended for in vitro diagnostic use for the calibration of assays for the following analytes: Benzoylecgonine, Methamphetamine, Morphine, PCP, Secobarbital and Oxazepam. The calibrators are designed for prescription use with immunoassays.
The Immunalysis Barbiturates Urine Enzyme Immunoassay consists of antibody/ substrate reagent and enzyme conjugate reagent. The antibody/ substrate reagent includes a recombinant antibody to Secobarbital, a mouse monoclonal antibody to Secobarbital, glucose-6-phosphate (G6P) and nicotinamide adenine dinucleotide (NAD) in HEPES buffer with sodium azide as a preservative. The enzyme conjugate reagent includes Barbiturates labeled with glucose-6phosphate dehydrogenase (G6PDH) in HEPES buffer with sodium azide as a preservative.
Immunalysis Multi-Drug Calibrators are included as part of the test system and provided separately. The calibrator kit includes four levels of drugs and a negative calibrator in a ready-touse format. Automated clinical chemistry analyzers capable of maintaining a constant temperature, pipetting samples and reagents, mixing reagents, timing the reaction accurately and measuring enzymatic rates spectrophotometrically at 340nm can be used to perform the assay.
The Immunalysis Barbiturates Urine Enzyme Immunoassay uses barbiturates recombinant and monoclonal antibody. The assay is based on the competition of Barbiturates labeled enzyme glucose-6-phosphate dehydrogenase (G6PDH) and the free drug in the urine sample for the fixed amount of antibody binding sites. In the absence of the free drug in the sample, the antibody binds the drug enzyme conjugate and enzyme activity is inhibited. This creates a dose response relationship between drug concentration in the urine and enzyme activity. The enzyme G6PDH activity is determined at 340 nm spectrophotometrically by the conversion of NAD to NADH.
Here's a breakdown of the acceptance criteria and study information for the Immunalysis Barbiturates Urine Enzyme Immunoassay:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria are not explicitly stated as distinct numerical targets within the provided text. However, the studies demonstrate the performance of the device in various metrics, and the conclusion states that the device is "substantially equivalent to the legally marketed predicate device for its intended use." This implies that the performance shown met the, albeit unstated, acceptance criteria for substantial equivalence to the predicate device.
For this analysis, I will infer the acceptance criteria from the context of how the results are presented, specifically the aim of demonstrating that the cutoff serves as a boundary between negative and positive interpretations, demonstrating appropriate cross-reactivity and non-interference, and showing high agreement with LC/MS-MS.
| Test / Performance Characteristic | Implied Acceptance Criteria (Inferred) | Reported Device Performance |
|---|---|---|
| Qualitative Analysis (Precision/Cutoff Characterization) | Clear discrimination around the 200 ng/mL cutoff (e.g., concentrations significantly below cutoff are consistently negative, significantly above consistently positive, at cutoff shows mixed results). | - 0-150 ng/mL: 80/80 Negative (100%) |
- 200 ng/mL (Cutoff): 33/80 Negative, 47/80 Positive
- 250-400 ng/mL: 80/80 Positive (100%) |
| Semi-Quantitative Analysis (Precision/Cutoff Characterization) | Clear discrimination around the 200 ng/mL cutoff and mixed results at cutoff. | - 0-150 ng/mL: 80/80 Negative (100%) - 200 ng/mL (Cutoff): 23/80 Negative, 57/80 Positive
- 250-400 ng/mL: 80/80 Positive (100%) |
| Specificity and Cross-Reactivity (Structurally Related Compounds) | Detect target compound (Secobarbital) at cutoff with 100% cross-reactivity; minimal or varying cross-reactivity for other barbiturates, with higher concentrations needed for positive results; Negative results for Phenytoin. | - Secobarbital: 100% Cross-Reactivity - Other Barbiturates: Cross-reactivity % varied from 0.3% (Hexobarbital, Mephobarbital) to 105.3% (Alphenal, Butobarbital)
- Phenytoin (100,000 ng/mL): Negative, 200 ng/mL and 200-300 ng/mL)
- Qualitative Negative: 100% Agreement (for 200 ng/mL and 200-300 ng/mL)
- Semi-Quantitative Negative: 100% Agreement (for
§ 862.3150 Barbiturate test system.
(a)
Identification. A barbiturate test system is a device intended to measure barbiturates, a class of hypnotic and sedative drugs, in serum, urine, and gastric contents. Measurements obtained by this device are used in the diagnosis and treatment of barbiturate use or overdose and in monitoring levels of barbiturate to ensure appropriate therapy.(b)
Classification. Class II (special controls). A barbiturate 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).