7th Workshop on Recent Issues in Bioanalysis Poster List Tuesday April 9 Posters Poster T01: "Validation of a Dried Blood Spot Boanalytical Method for Perampanel Analysis in Pediatric Studies" Poster Presenter: Dr. Luca Matassa (Eisai, Woodcliff Lake, NJ, USA) Introduction: Perampanel is a first-in-class, orally administered, highly selective non-competitive AMPA-type glutamate receptor antagonist, developed by EISAI for epilepsy. A DBS-LC-MS/MS method has been developed and validated in order to analyse perampanel in heparinised blood samples from paediatric studies. Dried blood spots (DBS) have been shown to be a useful means of collecting, storing and shipping blood samples for quantitative drug analysis which provides advantages over conventional plasma collection. Moreover, due to low sample volume that DBS uses, it is a method of choice when it is comes to paediatric studies. Methods: A 20 uL dried blood spot on FTA DMPK A card is punched (6mm punch) and the subsample is solubilized by shaking in 150 uL of 90/10 methanol water containing internal standard (IS) stable label peramapanel. An aliquot of the solution is diluted with an equal volume of 50/50 methanol/water, centrifuged at 4C for 5 min prior to injecting 10uL on a reverse phase column (Chromolith RP18e 100x3mm) at 40C under gradient conditions. The detector was a Sciex API5500 Qtrap operated in positive ion ionspray mode. Quantitation was achieved monitoring precursor/product ions for analyte and IS (350/219 m/z perampanel; 356/219 IS) at retention time 2.5 minutes using 1/x2 linear weighted regression. Result: A full validation according to FDA and EMA guidance was conducted in human blood. Assay linearity was demonstrated over 7 validation runs with R-squared greater than 0.995. The intra-run accuracy and precision was between 95.2 -107.6% and 3.1-12.6%, respectively, at four concentration levels (LLQ, low QC, mid QC, high QC) demonstrating the repeatability of the analytical method from 1 to 500 ng/mL. The matrix factor in 6 lots of control blood was 1.0 for analyte and IS. Control blank matrix showed no interference at the LLQ. Punch tool carryover and autoinjector carryover were not found to impact assay performance. Analyte and IS recovery was 80% across all 3 QC levels with imprecision less than 5%. A 2-fold dilution factor was validated. The specificity of the method for perampanel at the LLOQ in presence of 10 other commonly used AEDs, individual y or pooled all together, (valproic acid, phenobarbital, lamotrigine, topiramate, oxcarbazepine, carbamazepine, levetiracetam, zonisamide, phenytoin, primidone) was demonstrated. A blood/plasma ratio of 0.88 was determined, allowing the correlation between blood and previous study plasma results. Short term autosample perampanel extract stability and perampanel stability in blood was demonstrated. Perampanel long term stability on DBS was demonstrated for 363 days at room temperature. Novel Aspect / Conclusion: The fully validated DBS-LC-MS/MS method was successfully applied to analysis of paediatric study clinical samples. Poster T02: "Unexpected Results for Sample Col ection and Handling Stability Assessment for Sumatriptan in Human Plasma" Poster Presenter: Ginny James (Celerion, Lincoln, Nebraska, USA) Introduction: Determination of sample col ection and handling stability (SCHS) is a requirement for validation of bioanalytical methods. SCHS of sumatriptan for 120 minutes did not meet pre-defined acceptance criteria. As sumatriptan was stable in plasma for 23 hours at ambient temperature, it was hypothesized that partitioning of sumatriptan between plasma and red blood cells was not immediate and was impacting the results of the early time points. Methods: Whole blood was fortified with sumatriptan at 0.150 and 100 ng/mL for target plasma concentrations of approximately 0.300 and 200 ng/mL. The samples were incubated in an ice-water bath, at ambient temperature, and at 37°C for multiple time points between 0 and 120 minutes. At each time point, samples were centrifuged, and the plasma layer was immediately frozen at -20°C. For samples in an ice-water bath for 30 minutes, the red cell fraction was also stored at -20°C for testing. The collected plasma samples were analyzed using a validated method for the quantitation of sumatriptan in human plasma. Red blood cel s were analyzed with the same chromatographic and instrument conditions after a protein crash of the cellular material.