Summary of Registration Evaluation of Colloidal Gold Immunochromatography Drug Abuse Detection Reagents
1. Intended use
The intended use of the product reflects its function and function, and defines its usage scenarios. The purpose of drug abuse detection is to help clinicians make judgments on the recent medication of patients. In view of this feature, this type of detection reagent is usually used for the primary screening of drug abuse in qualified medical institutions. If further confirmation and evaluation is required, use detection methods such as liquid chromatography-mass spectrometry (LC-MS) with higher sensitivity and specificity.
2. Analysis performance
1. Selection of sample type
According to the different ways in which the toxic components of the abused drugs are discharged into the human body, the test samples are also varied. Toxic components in urine and saliva are metabolized quickly and are often used as test samples for evaluation.
2. Accuracy evaluation
The evaluation of product accuracy can choose the detection or methodological comparison of reference products. Among them, the detection of the reference product requires that the sample matrix is the same as the clinical sample, and the sample must be prepared through a standard product with a recognized value. Methodological comparison is divided into comparison with similar reagents already on the market and comparison with reference methods such as liquid chromatography-mass spectrometry (LC-MS). The samples used in the accuracy study were required to contain all drugs or metabolites known to have significant cross-reactivity in samples near the limit of detection.
3. Precision evaluation
At least 3 levels of real samples should be used for research, and samples at the detection limit level should be included, and the influence of factors such as the number of runs, testing time, testing location, operator, and reagent batches should be considered to determine the detection coincidence rate of each sample. , Coefficient of variation for evaluation.
4. Detection limit evaluation
The evaluation of detection limit should include two parts: detection limit determination and verification. For most drugs, the relevant technical guidelines in my country and the detection limit concentration determined by the US Substance Abuse and Mental Health Services Administration (SAMHSA) can be directly used. If there is no recommended detection limit, the registrant can establish it according to the relevant drug metabolism. The detection limit. The verification of the detection limit should be carried out using real samples of the concentration of the detection limit minus 25%, the detection limit and the detection limit plus the concentration of 25%.
For products whose analytes include major drug metabolites and their structural analogs, the detection limits of their metabolites and their structural analogs need to be determined and verified at the same time.
5. Specificity evaluation
5.1 Cross-reactivity
Cross-reactivity needs to be evaluated for all drugs/compounds, drug metabolites, and structural analogs that may have cross-reactions in the same class of drugs. The above-mentioned substances are prepared by adding the above-mentioned substances to normal human samples without drugs. The highest expected levels in vivo were comparable. Drugs with a positive test result should be serially diluted and tested until the highest drug concentration at which the test result is negative is obtained.
5.2 Interfering substances
Commonly used drugs or substances absorbed and metabolized, endogenous substances and physiological conditions, and photochromic substances will all affect the test results. It is recommended that the registrant evaluate the potential maximum concentration and medically relevant level concentration of each interfering substance, and should The positive interference effect and negative interference effect of each interfering substance were evaluated separately at the level near the drug detection limit.
3. Positive judgment value
The judgment of negative/positive results of this type of product depends on the detection limit of the product, so its detection limit can be used as the positive judgment value. If the tested substances of the product also include the main metabolites of the drug and their structural analogs, then the positive judgment value should also consider the detection limit of their metabolites and structural analogs.
4. Clinical evaluation
For the drug abuse detection reagents that have been included in the "Catalogue of In Vitro Diagnostic Reagents Exempted from Clinical Trials", the clinical evaluation can be carried out by methodological comparison with similar domestic marketed products. For products with multiple packaging specifications, the clinical evaluation should cover all packaging specifications of the product, and conduct summary statistics and stratified statistics for different packaging specifications. At the same time, at least 60 samples within the detection range should be selected for comparison with reference methods such as liquid chromatography-mass spectrometry.
The samples for methodological comparison with products already on the market should comply with the relevant requirements of the "Technical Guidelines for Clinical Evaluation of In Vitro Diagnostic Reagents Exempted from Clinical Trials". The comparison with the reference method is mainly based on positive samples, and includes some negative samples, samples with detection limit, samples with a concentration of about 50% above and below the detection limit, etc.
