Validation of the Neogen® enzyme-linked immunosorbent assay gabapentin kit for blood and urine

The validation of a semi-quantitative method for the rapid screening of whole blood and urine specimens using the Neogen® Gabapentin kit is presented. Decision points were validated at 1000 ng/mL for whole blood and urine. The validation design was based on ANSI/ASB 036 and internal laboratory requirements. Experiments included the evaluation of sensitivity, precision, specificity, carryover, hook effect, drift, ruggedness/robustness, interference, and an authentic case sample comparison. The experimental limit of detection (LOD) for gabapentin was determined to be at least 500 ng/mL in whole blood and urine. Excellent precision was demonstrated when the assay was evaluated using the mean of three replicates from five separate runs (n = 15) at the decision point and at concentration levels -50% and +100% of the decision point. The assay was reliably able to detect gabapentin without interference from matrix components or other substances routinely detected in authentic case samples with the exception of levamisole in urine if present at unusually high concentrations. Urine samples with 50 µg/mL or more of levamisole yielded a false positive screening result. Other case sample results were comparable to those obtained with liquid chromatography tandem high-resolution mass spectrometry or liquid chromatography tandem mass spectrometry for blood and urine, respectively. The Neogen® Gabapentin kit exhibited minimal cross-reactivity for pregabalin and demonstrated excellent precision and appropriate sensitivity in both whole blood and urine, making it an efficient and reliable method to screen for gabapentin.