OMEGA LABORATORIES HAIR DRUG SCREENING ASSAY FOR PHENCYCLIDINE

{0} 1 # 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY ASSAY ONLY TEMPLATE A. 510(k) Number: k101059 B. Purpose for Submission: New device C. Measurand: Phencyclidine (PCP) in hair D. Type of Test: Qualitative ELISA Immunoassay E. Applicant: Omega Laboratories, Inc. F. Proprietary and Established Names: Omega Laboratories Hair Drug Screening Assay for Phencyclidine (PCP) G. Regulatory Information: | Product Code | Classification | Regulation Section | Panel | | --- | --- | --- | --- | | LCM, Enzyme immunoassay | Class II | Unclassified | 91-Toxicology | | Phencyclidine | | | | H. Intended Use: 1. Intended use(s): See Indications for use below. 2. Indication(s) for use: {1} The Omega Laboratories Hair Drug Screening Assay Phencyclidine (PCP) is a laboratory developed test that is intended to be used for the determination of the presence of PCP in human hair from the head. The Omega Laboratories Hair Drug Screening Assay (PCP) utilizes the International Diagnostic System Corp (IDS) One-Step enzyme linked immunosorbant assay (ELISA) for PCP, for the qualitative detection of PCP at or above 300 pg/mg of hair for the purpose of identifying the use of PCP. To confirm a screen positive result, a more specific alternate chemical method, such as Gas Chromatography/Mass Spectrometry (GC/MS) operating in the selected ion monitoring (SIM) mode is the preferred method with deuterated internal standards. Professional judgment should be applied to any drug of abuse test result, particularly when presumptive positive results are obtained. This laboratory developed test is intended exclusively for in-house laboratory use only and is not intended for sale to anyone. Omega offers this laboratory developed test as a service to its clients. 3. Special conditions for use statement(s): The assay is for Prescription Use 4. Special instrument requirements: The screening assay is for use with an automated microplate reader capable of measuring at 450 nm. I. Device Description: The assay consists of the following: - Antibody coated microplate – 5x 96-well microplate coated with goat anti-PCP polyclonal high affinity antibody - Enzyme conjugate concentrate – 1 ml drug analyte conjugated to HRP - Enzyme diluent – 85 ml to dilute enzyme conjugate - Wash solution (10x) – 100 ml (Dilute 1:10 with deionized water prior to use) - K-Blue substrate – 100 ml-3,3',5,5'-Tetramethylbenzidine (TMB) - Stop solution – 90 ml 1N H₂SO₄ - Hair sample collection kit - Calibrators and controls. These are prepared solutions of PCP added to negative hair matrix tubes. J. Substantial Equivalence Information: 1. Predicate device name(s): Quest Diagnostic HairCheck-DT (PCP) 2. Predicate K number(s): {2} k042726 3. Comparison with predicate: | Item | Device | Quest Hair Drug Screening k042726 | | --- | --- | --- | | Indications/Intended Use | Intended to be used for the determination of the presence of PCP in human Hair | Same | | Test System | International Diagnosticx Systems Corp Forensic Human Drug of Abuse One-Step ELISA for Hair Testing Kit – IDS part # PCP-480-OM | Same | | Sample matrix | Head Hair | Same | | Method of measurement | Microplate reader, read at 450 nm | Same | | Cutoff | 300 pg/mg | Same | | Type of test | ELISA | Same | | Extraction methods | Utilized acid-methanol vs methanol alone to facilitate extraction of PCP from hair. | Methanol | | Confirmation method | GC/MS | Same | | Measurand | Phencyclidine (PCP) in hair | Same | K. Standard/Guidance Document Referenced (if applicable): None referenced L. Test Principle: The test consists of two parts; a pre-analytical hair treatment procedure (to convert the solid matrix of hair to a measurable liquid matrix), the screening assay. The screening assay is an Enzyme-Linked ImmunoSorbent Assay (ELISA). Sample is added to a well of the micro strip plate and enzyme conjugate is added, followed by incubation. During this phase the enzyme-labeled drug conjugate competes with drug in the sample for a limited number of binding sites on the antibody-coated micro wells. The two bind in proportion to their concentrations. A wash solution is applied to remove unbound materials. Enzyme substrate solution containing a chromagen is added. The reaction is stopped with a stop solution and absorbance is read using a plate reader at $450~\mathrm{nm}$ . A background reading is also taken at $630~\mathrm{nm}$ . Color intensity is inversely proportional to the amount of drug presented in the sample. {3} M. Performance Characteristics (if/when applicable): 1. Analytical performance: a. Precision/Reproducibility: Precision studies were performed by taking commercially available materials consisting of PCP in methanol (with a Certificate of Analysis traceable to NIST) to prepare spiking solutions at the following concentrations; negative, ±75%, ±50%, ±25% and 200% of the cutoff. The concentration of each sample was confirmed by GC/MS. Each solution was then used to spike 11 replicates of negative hair samples. Intra-assay precision was performed in one run and inter-assay precision was performed over 20 days. The results are present in the tables below: | Intra-assay PCP Cutoff = 300 pg/mg | | | | | | --- | --- | --- | --- | --- | | Conc. (pg/mg) | % of Cutoff | Number Tested | Negative | Positive | | 0 | Negative | 11 | 11 | 0 | | 75 | 75 | 11 | 11 | 0 | | 150 | 50 | 11 | 11 | 0 | | 225 | 25 | 11 | 11 | 0 | | 375 | 125 | 11 | 0 | 11 | | 450 | 150 | 11 | 0 | 11 | | 525 | 175 | 11 | 0 | 11 | | 600 | 200 | 11 | 0 | 11 | | Inter-assay PCP Cutoff = 300 pg/mg | | | | | | --- | --- | --- | --- | --- | | Conc. (pg/mg) | % of Cutoff | Number Tested | Negative | Positive | | 0 | Negative | 220 | 220 | 0 | | 75 | 75 | 220 | 220 | 0 | | 150 | 50 | 220 | 220 | 0 | | 225 | 25 | 220 | 220 | 0 | | 375 | 125 | 220 | 0 | 220 | | 450 | 150 | 220 | 0 | 220 | | 525 | 175 | 220 | 0 | 220 | | 600 | 200 | 220 | 0 | 220 | The sponsor also performed an intra-assay precision using 5 hair specimens previously found to be positive for PCP. Each specimen was divided into 6 aliquots. Three aliquots were treated and analyzed on the device in one run. Additional, three aliquots were analyzed by GC/MS. The results are presented below: {4} | GC/MS | Device | | | | --- | --- | --- | --- | | Conc. (pg/mg) | Number Tested | Negative | Positive | | 399 | 3 | 0 | 3 | | 560 | 3 | 0 | 3 | | 1435 | 3 | 0 | 3 | | 4528 | 3 | 0 | 3 | | 7096 | 3 | 0 | 3 | b. Linearity/assay reportable range: Not applicable. This is a qualitative assay. c. Traceability, Stability, Expected values (controls, calibrators, or methods): Commercially purchased materials consisting of PCP in methanol are used to prepare stock solutions. Stock solutions are then used to prepare calibrator and control working solutions. The cerillant PCP standard is traceable back to NIST. Assigned values of the prepared calibrator and control working solutions are verified by GC/MS analysis each time a new batch is prepared. The calibrator must fall with 10% of the targeted concentration. Protocols and acceptance criteria for stability testing were described and found to be acceptable. When stored refrigerated in an amber bottle the shelf life is 12 months. d. Detection limit: Performance at low concentrations was evaluated in the precision studies above. This is a qualitative assay. e. Analytical specificity: Structurally Related: Cross-reactivity to structurally-related compounds was evaluated by preparing serial dilutions of each control compound in negative hair matrix extract and evaluated against the cutoff control. Results are expressed as a minimum concentration of compound required to produce a response approximately equivalent to the cutoff concentration of the assay. The results are presented in the table below: {5} | Compound | Approximate concentration of compound (pg/mg) Equivalent to 300 pg/mg Phencyclidine Cutoff Control n=3 | % Cross reactivity | | --- | --- | --- | | Phencyclidine | 300 | 100 | | Metaphit | 500 | 60 | | 4-Hydroxy- Phencyclidine | 6000 | 5.0 | | Doxylamine | >40000 | <0.8 | | Phencyclidine Morpholine | 1500 | 20 | Structurally unrelated: Negative hair extracts were spiked with phencyclidine to -50%, 125% and 150% of the cutoff. Several (270) structurally related and unrelated compounds were added to methanol to a concentration of 10,000 ng/ml then added to the hair matrix tubes. Samples were evaluated in triplicate and the listed compounds can be found in the package insert. Compounds that are not structurally similar to PCP have not been observed to produce an interference with the assay. Only those compounds that are structurally similar (metaphit, 4-hydroxyphencyclidine and phencyclidine morpholine) were shown to contribute to a PCP positive ELSIA screening result. There is the possibility that other substances and/or factors not listed above may interfere with the test and cause false results. Hair Treatment: The effects of various hair treatments (i.e. bleaching, dyeing, relaxer, shampoo, permanent) on the ELISA screening and GC/MS conformation for both positive and negative PCP samples was performed. Effect on Positive Samples: One hundred and thirty nine hair specimens potentially positive for PCP were obtained. Of these 139 samples 90 were confirmed positive for PCP. Each sample was divided into 2 aliquots. One aliquot of each sample were randomly assigned into one of 10 groups, 9 samples in each group and subjected to the treatment. ELSIA Absorbance readings before and after treatment were compared. GC/MS measurements before and after treatment were also compared. The data is presented in the tables below: {6} Effects Observed in the Bleaching Study 1 | ELISA Screening Data | | | | | | | --- | --- | --- | --- | --- | --- | | | Mean Abs/Range of Abs | # of samples that remained positive | Mean/Range of Abs of all that had a decrease in Abs | # of samples that became negative | Mean/Range of Abs of all that had a increase in Abs | | Untreated | 0.359 (0.093-0.660) | | | | | | Treated | 0.354 (0.075-0.635) | 9 | 0.253 (0.075-0.583) | 0 | 0.557 (0.494-0.635) | | GC/MS Confirmation data | | | | | | | | Mean/Range of sample concentration (pg/mg) | # of samples that decreased in concentration | Mean/Range of decrease in concentration | # of samples that increased in concentration | Mean/Range of increase in concentration | | Untreated | 2751 (334-6778) | | | | | | Treated | 2257 (298-6381) | 9 | 494 (37-1330) | 0 | --- | Effects Observed in the Bleaching Study 2 | ELISA Screening Data | | | | | | | --- | --- | --- | --- | --- | --- | | | Mean Abs/Range of Abs | # of samples that remained positive | Mean/Range of Abs of all that had a decrease in Abs | # of samples that became negative | Mean/Range of Abs of all that had a increase in Abs | | Untreated | 0.331 (0.074-0.509) | | | | | | Treated | 0.326 (0.074-0.560) | 9 | 0.286 (0.074-0.399) | 0 | 0.376 (0.150-0.560) | | GC/MS Confirmation data | | | | | | | | Mean/Range of sample concentration (pg/mg) | # of samples that decreased in concentration | Mean/Range of decrease in concentration | # of samples that increased in concentration | Mean/Range of increase in concentration | | Untreated | 1941 (612-7304) | | | | | | Treated | 1534 (525-5195) | 9 | 407 (87-2109) | 0 | --- | Effects Observed in the PERM Study 1 | ELISA Screening Data | | | | | | | --- | --- | --- | --- | --- | --- | | | Mean Abs/Range of | # of samples that | Mean/Range of Abs of all | # of samples that became | Mean/Range of Abs of all | {7} 8 Effects Observed in the PERM Study 2 | ELISA Screening Data | | | | | | | --- | --- | --- | --- | --- | --- | | | Mean Abs/Range of Abs | # of samples that remained positive | Mean/Range of Abs of all that had a decrease in Abs | # of samples that became negative | Mean/Range of Abs of all that had a increase in Abs | | Untreated | 0.465 (0.104-0.702) | | | | | | Treated | 0.526 (0.132-0.819) | 6 | 0.334 (only 1 sample) | 3 | 0.550 (0.132-0.819) | | GC/MS Confirmation data | | | | | | | | Mean/Range of sample concentration (pg/mg) | # of samples that decreased in concentration | Mean/Range of decrease in concentration | # of samples that increased in concentration | Mean/Range of increase in concentration | | Untreated | 1465 (301-5244) | | | | | | Treated | 1261 (177-4291) | 9 | 203 (17-786) | 0 | --- | Effects Observed in the DYE Study 1 | ELISA Screening Data | | | | | | | --- | --- | --- | --- | --- | --- | | | Mean Abs/Range of Abs | # of samples that remained positive | Mean/Range of Abs of all that had a decrease in Abs | # of samples that became negative | Mean/Range of Abs of all that had a increase in Abs | | Untreated | 0.468 | | | | | {8} Effects Observed in the DYE Study 2 | ELISA Screening Data | | | | | | | --- | --- | --- | --- | --- | --- | | | Mean Abs/Range of Abs | # of samples that remained positive | Mean/Range of Abs of all that had a decrease in Abs | # of samples that became negative | Mean/Range of Abs of all that had a increase in Abs | | Untreated | 0.442 (0.123-0.688) | | | | | | Treated | 0.456 (0.099-0.777) | 8 | 0.313 (0.099-0.608) | 1 | 0.636 (0.414-0.777) | | GC/MS Confirmation data | | | | | | | | Mean/Range of sample concentration (pg/mg) | # of samples that decreased in concentration | Mean/Range of decrease in concentration | # of samples that increased in concentration | Mean/Range of increase in concentration | | Untreated | 1575 (307-4954) | | | | | | Treated | 2257 (298-6381) | 5 | 44 (6-102) | 4 | 182 (9-312) | Effects Observed in the Relaxer Study 1 | ELISA Screening Data | | | | | | | --- | --- | --- | --- | --- | --- | | | Mean Abs/Range of Abs | # of samples that remained positive | Mean/Range of Abs of all that had a decrease in Abs | # of samples that became negative | Mean/Range of Abs of all that had a increase in Abs | | Untreated | 0.417 (0.129-0.678) | | | | | | Treated | 0.441 (0.132-0.709) | 9 | 0.387 (0.146-0.672) | 0 | 0.467 (0.132-0.709) | | GC/MS Confirmation data | | | | | | {9} Effects Observed in the Relaxer Study 2 | ELISA Screening Data | | | | | | | --- | --- | --- | --- | --- | --- | | | Mean Abs/Range of Abs | # of samples that remained positive | Mean/Range of Abs of all that had a decrease in Abs | # of samples that became negative | Mean/Range of Abs of all that had a increase in Abs | | Untreated | 0.505 (0.163-0.691) | | | | | | Treated | 0.547 (0.150-0.835) | 8 | 0.471 (0.150-0.636) | 1 | 0.642 (0.555-0.835) | | GC/MS Confirmation data | | | | | | | | Mean/Range of sample concentration (pg/mg) | # of samples that decreased in concentration | Mean/Range of decrease in concentration | # of samples that increased in concentration | Mean/Range of increase in concentration | | Untreated | 758 (305-2764) | | | | | | Treated | 758 (275-2783) | 6 | 59 (12-141) | 3 | 28 (15-51) | Effects Observed in the Shampoo Study 1 | ELISA Screening Data | | | | | | | --- | --- | --- | --- | --- | --- | | | Mean Abs/Range of Abs | # of samples that remained positive | Mean/Range of Abs of all that had a decrease in Abs | # of samples that became negative | Mean/Range of Abs of all that had a increase in Abs | | Untreated | 0.451 (0.320-0.685) | | | | | | Treated | 0.473 (0.274-0.686) | 9 | 0.319 (0.274-0.390) | 0 | 0.597 (0.475-0.686) | | GC/MS Confirmation data | | | | | | | | Mean/Range of sample concentration (pg/mg) | # of samples that decreased in concentration | Mean/Range of decrease in concentration | # of samples that increased in concentration | Mean/Range of increase in concentration | {10} 11 | Untreated | 766 (311-1430) | | | | | | --- | --- | --- | --- | --- | --- | | Treated | 744 (267-1447) | 6 | 41 (7-77) | 3 | 18 (15-21) | Effects Observed in the Shampoo Study 2 | ELISA Screening Data | | | | | | | --- | --- | --- | --- | --- | --- | | | Mean Abs/Range of Abs | # of samples that remained positive | Mean/Range of Abs of all that had a decrease in Abs | # of samples that became negative | Mean/Range of Abs of all that had a increase in Abs | | Untreated | 0.417 (0.275-0.620) | | | | | | Treated | 0.445 (0.263-0.683) | 9 | 0.275 (0.263-0.297) | 0 | 0.547 (0.432-0.683) | | GC/MS Confirmation data | | | | | | | | Mean/Range of sample concentration (pg/mg) | # of samples that decreased in concentration | Mean/Range of decrease in concentration | # of samples that increased in concentration | Mean/Range of increase in concentration | | Untreated | 827 (305-1784) | | | | | | Treated | 820 (287-1709) | 6 | 56 (18-125) | 3 | 90 (77-114) | Effect on Negative Samples: Eighty six hair specimens (37 previously confirmed negative for PCP and 49 from the 139). Each sample was divided into 2 aliquots. One aliquot of each sample were randomly assigned into one of 10 groups, 9 samples in each group and subjected to the treatment. ELSIA Absorbance readings before and after treatment were compared. GC/MS measurements before and after treatment were also compared. For the bleaching, perming and dyeing there was a small change in the percent difference between the mean absorbance values of the treated and untreated groups. The difference was not enough to change the result. No effect was observed for the relaxer and shampoo treatments. Conclusion: Permanent treatments had the greatest effect on positive samples followed by bleaching resulting which causes a decrease in PCP concentration potentially having a PCP result as negative instead of positive. Environmental Contamination: {11} Two studies were performed to investigate whether confirmatory testing procedures (methanol wash procedure) are able to distinguish between true analytically positive samples and those that have been externally exposed to PCP. The study focused on demonstrating that the methanol wash procedure mitigates the risk of false positive results while maintaining true analytical positive results. The first study involved exposing drug-free hair to PCP, washing the hair with methanol, performing confirmation testing on the samples and the washes and observing the final result. Ten hair specimens that had previously screened negative for PCP were selected in order to represent two hair types, listed below: Hair Types | Category | Hair Color | Hair Texture | | --- | --- | --- | | A | Black | Curly | | B | Blonde | Straight | Five hair specimen aliquots of each hair type were exposed to PCP (in separate experiments) according to the exposure modes listed below. Approximately $20\mathrm{mg}$ aliquot of each hair sample were then analyzed by GC/MS. Results are presented for each exposure mode and according to the drug and category of hair type. Exposure Modes <table><tr><td>Type of Exposure</td><td>How performed</td></tr><tr><td>Dry Contact</td><td>Exactly 1.0 mg of phencyclidine hydrochloride was weighed and then combined with 10 grams of dextrose with maltodextrin, aspartame (Splenda®). The powdered mixture was mixed thoroughly for homogeneity using a mortar and pestle. Exactly 5 grams of powder was added to the bottom of a 1 liter beaker. A lid containing both hair types attached to hair clips was affixed to the top and sealed with parafilm. The powder at the bottom of the beaker was disturbed by applying a burst of compressed gas with a compressed gas canister. The lid only allowed the small tube to deliver compressed gas, allowing powder to become airborne and distribute as a cloud inside the 1 liter container. The hair bundles remained in the container for 30 minutes of exposure to the airborne powder. The PCP powder-exposed hair were then taken out of the beaker and shaken to remove excess power. Separate 20 mg aliquots of each hair specimen were weighed and placed into individual test tubes.</td></tr><tr><td>Dry Contact plus Liquid</td><td>After dry contact exposure as described above, 20 mg aliquots of each hair specimen were weighed out and 2.0 mL of water was added and then quickly removed to simulate rinsing the hair, as in</td></tr><tr><td></td><td>the beaker. The beaker was then washed with water and then washed with water and then washed with water. The beaker was then washed with water and then washed with water. The beaker was then washed with water and then washed with water. The beaker was then washed with water and then washed with water. The beaker was then washed with water. The beaker was then washed with water. The beaker was then washed with water. The beaker was then washed with water. The beaker was then washed with water. The beaker was then washed with water. The beaker was then washed with water. The beaker was then washed with water. The beaker was then washed with water. The beaker was then washed with water. The beaker was then washed with water. The beaker was then washed with water. The beaker was then washed with water. The beaker was then washed with water. The beaker was then washed with water. The beaker was then washed with water. The beaker was {12} 13 | | a shower or bathing. An additional 2.0 mL of water was added and the tube was allowed to stand for 30 minutes at ambient temperature. The water was then removed and the hair was allowed to dry overnight. Separate 20 mg aliquots of each hair specimen were weighed and placed into individual test tubes. | | --- | --- | | Dry Contact plus Saline | After dry contact exposure as described above 20 mg aliquots of hair were weighed out and 0.3 mL of saline (0.9% sodium chloride solution) was added. The saline solution was sufficient to saturate the hair specimen and also expose a fraction of the hair with constant soaking, to simulate sweating close to the scalp. The tube was allowed to stand for 30 minutes at ambient temperature. The saline solution was then removed and the hair was allowed to dry overnight. Separate 20 mg aliquots of each hair specimen were weighed and placed into individual test tubes. | | Smoke Contact | A total of 10 hair specimens known to be drug-free were exposed to PCP smoke by burning a tobacco cigarette soaked in 3.0 mg of PCP in an enclosed 5 gallon bucket. The ten hair specimens attached to hair clips on a string were hung inside the bucket. A cigarette was lit first, and a pipette was used to apply 300 uL of a 10 mg/mL PCP solution on the cigarette. It was then placed in an aluminum foil tray, and the cigarette was allowed to completely burn with the specimens remaining in the bucket overnight. After exposure to the PCP smoke, separate 20 mg aliquots of each hair specimen were weighed into two and placed into individual test tubes. | ## Dry Contact Exposure | Specimen | 1^{st} Methanol Wash (PCP pg/mg) | 2^{nd} Methanol Wash (PCP pg/mg) | 3^{rd} Methanol Wash (PCP pg/mg) | Hair Specimen (PCP pg/mg) | | --- | --- | --- | --- | --- | | A1 | 617 | 67 | None detected | None detected | | A2 | 1028 | 247 | None detected | None detected | | A3 | 944 | 77 | None detected | None detected | | A4 | 792 | 48 | None detected | None detected | | A5 | 256 | None detected | None detected | None detected | | B1 | 619 | 50 | None detected | None detected | | B2 | 697 | 89 | None detected | None detected | | B3 | 551 | 75 | None detected | None detected | | B4 | 631 | 84 | None detected | None detected | | B5 | 876 | 95 | None detected | None detected | ## Dry Contact with Liquid Exposure | Specimen | 1^{st} Methanol Wash (PCP pg/mg) | 2^{nd} Methanol Wash (PCP pg/mg) | 3^{rd} Methanol Wash (PCP pg/mg) | Hair Specimen (PCP pg/mg) | | --- | --- | --- | --- | --- | | A1 | 670 | 67 | None detected | None detected | {13} Dry Contact with Saline Exposure | Specimen | 1stMethanol Wash (PCP pg/mg) | 2ndMethanol Wash (PCP pg/mg) | 3rdMethanol Wash (PCP pg/mg) | Hair Specimen (PCP pg/mg) | | --- | --- | --- | --- | --- | | A1 | 666 | 26 | None detected | None detected | | A2 | 447 | 51 | None detected | None detected | | A3 | 857 | 68 | None detected | None detected | | A4 | 627 | 104 | None detected | None detected | | A5 | 997 | 20 | None detected | None detected | | B1 | 2035 | 41 | None detected | None detected | | B2 | 871 | 84 | None detected | None detected | | B3 | 442 | 32 | None detected | None detected | | B4 | 826 | 20 | None detected | None detected | | B5 | 708 | 44 | None detected | None detected | Smoke Exposure | Specimen | 1stMethanol Wash (PCP pg/mg) | 2ndMethanol Wash (PCP pg/mg) | 3rdMethanol Wash (PCP pg/mg) | Hair Specimen (PCP pg/mg) | | --- | --- | --- | --- | --- | | A1 | 314 | 25 | None detected | None detected | | A2 | 269 | 42 | None detected | None detected | | A3 | 281 | 82 | None detected | None detected | | A4 | 318 | 57 | None detected | None detected | | A5 | 343 | 84 | None detected | None detected | | B1 | 466 | 33 | None detected | None detected | | B2 | 465 | 55 | None detected | None detected | | B3 | 377 | 95 | None detected | None detected | | B4 | 439 | 38 | None detected | None detected | | B5 | 291 | 42 | None detected | None detected | The second study involved performing confirmation testing on known positive samples and observing whether the methanol washes change the final result. Five clinically positive hair samples were selected for the study. All samples were previously screened and confirmed positive. Results are presented below: {14} Conclusions of the study: Evaluating potential external contamination using this study design, all analytically negative samples tested remained negative after being subjected to PCP and exposure modes described. All clinically positive samples tested remained positive. f. Assay cut-off: Analytical performance of the device around the claimed cutoff is described in precision section M.1a above 2. Comparison studies: The study was performed by comparing ELSIA results against the GC/MS results on the same hair sample. A total of 352 donor hair samples were tested (176 negative and 176 positive). The results are presented in the table below: a. Method comparison with GC/MS: | IDS ELSIA PCP Test Result | Negative by GC/MS (less than 50 pg/mg) | Less then half the cutoff concentration by GC/MS | Near Cutoff Negative (Between 50% below the cutoff and the cutoff concentration) | Near Cutoff Positive (Between the cutoff and 50% above the cutoff concentration) | High Positive (Greater than 50% above the cutoff concentration) | | --- | --- | --- | --- | --- | --- | | Positive | 0 | 1 | 14 | 33 | 128 | | Negative | 150 | 15 | 7 | 4 | 0 | Discrepant Results: | Screening Cutoff (pg/mg) | IDS ELSIA PCP Test Results (POS/NEG) | GC/MS Cutoff (pg/mg) | GC/MS Drug Result (pg/mg) | | --- | --- | --- | --- | | 300 | POS | 300 | 122 | | 300 | POS | 300 | 166 | | 300 | POS | 300 | 184 | {15} | 300 | POS | 300 | 264 | | --- | --- | --- | --- | | 300 | POS | 300 | 267 | | 300 | POS | 300 | 272 | | 300 | POS | 300 | 280 | | 300 | POS | 300 | 286 | | 300 | POS | 300 | 287 | | 300 | POS | 300 | 287 | | 300 | POS | 300 | 288 | | 300 | POS | 300 | 290 | | 300 | POS | 300 | 291 | | 300 | POS | 300 | 293 | | 300 | POS | 300 | 298 | | 300 | NEG | 300 | 301 | | 300 | NEG | 300 | 301 | | 300 | NEG | 300 | 305 | | 300 | NEG | 300 | 313 | b. Matrix comparison: Not applicable. The assay is intended for only one sample matrix. 3. Clinical studies: a. Clinical Sensitivity: Not applicable b. Clinical specificity: Not applicable c. Other clinical supportive data (when a. and b. are not applicable): Extraction Recovery Study: Five hair samples that previously confirmed positive for PCP were used for these studies. Samples were aliquoted in duplicate; one aliquot was taken through the screening assay acidic-methanol extraction and the other was taken through the 100% recovery extraction. One aliquot for each hair sample was taken through the screening extraction and assay procedures (described in the Test Principle Section above) up to the point of evaporating the acidic-methanol extract. At this point, GC/MS confirmation Procedure for PCP in hair was followed. The method representing 100% recovery was accomplished by adding 1.0 ml of 1N NaOH to 20 mg of hair and incubated at 70°C for 30 minutes. The hair 16 {16} sample is totally liquefied and the entire drug originally bound to the hair is now dissolved in the base solution. At this point the GC/MS conformation procedure for PCP was followed. The GC/MS results of the acidic-methanol extraction were compared to the results of the 100% recovery base hydrolysis extraction to determine the relative recovery of PCP using the acidic-methanol incubation. The mean recovery for the acidic-methanol extraction was 102%. The results are in the table below: | Sample | Acidic-methanol (pg/mg) | Base Hydrolysis (pg/mg) | Recovery | | --- | --- | --- | --- | | 176160 | 418 | 457 | 91% | | 176161 | 250 | 233 | 107% | | 176163 | 126 | 104 | 121% | | 254474 | 261 | 251 | 104% | | 406560 | 300 | 337 | 89% | 4. Clinical cut-off: Not applicable 5. Expected values/Reference range: Not applicable N. Proposed Labeling: The labeling is sufficient and it satisfies the requirements of 21 CFR Part 809.10. O. Conclusion: The submitted information in this premarket notification is complete and supports a substantial equivalence decision. 17