Single-dose pharmacokinetics of amphetamine extended-release tablets compared with amphetamine extended-release oral suspension

Evaluate the relative bioavailability of single-dose amphetamine extended-release tablet (AMPH ER TAB) 20 mg, swallowed whole or chewed, and amphetamine extended-release oral suspension (AMPH EROS) 2.5 mg/mL; evaluate food effect on AMPH ER TAB. Healthy volunteers (18-55 years) were randomized to 1 dose of AMPH ER TAB 20 mg swallowed (fasted), chewed (fed/fasted), or 20 mg AMPH EROS (fasted). A crossover study design was used. Plasma samples were collected each period predose and at time points to 60 hours postdose. d- and l-amphetamine were measured and pharmacokinetic (PK) was calculated (90% confidence intervals of the ratios of the plasma levels) for AUC0-t, AUC0-∞, and Cmax. Comparative relative bioavailability between formulations was determined when ratios were within 80% and 125%. Safety was also assessed. Thirty-two subjects completed the study. AMPH ER TAB swallowed versus AMPH EROS (fasted): for d- and l-amphetamine, the total and peak exposure was similar: d: AUC0-t: 100.68% to 108.08%, AUC0-∞: 101.47% to 109.52%, Cmax: 98.10% to 103.17%; l: AUC0-t: 100.31% to 108.57%, AUC0-∞: 101.27% to 111.09%, Cmax: 98.2% to 103.37%. For d- and l-amphetamine when the tablet is swallowed whole, Tmax was 5.00 hours (with a range of 2.00-9.00 hours). AMPH ER TAB chewed versus AMPH EROS (fasted): for d- and l-amphetamine, the total and peak exposure was similar: d: AUC0-t: 99.23% to 106.62%, AUC0-∞: 99.58% to 107.59%, Cmax: 99.91% to 105.14%; l: AUC0-t: 98.16% to 106.35%, AUC0-∞: 98.44% to 108.11%, Cmax: 99.53% to 104.75%. For d- and l-amphetamine when the tablet has been chewed, Tmax was 5.00 hours (with a range of 3.00-7.00 hours). PK results were similar for patients in the fasted and fed groups, indicative of no presence of food effect. No serious adverse events (AEs) were reported, overall AE profiles between the tablet and oral suspension were comparable without any unanticipated safety concerns. Single doses of AMPH ER TAB for both d- and l-amphetamine demonstrated comparable bioavailability to a 20 mg dose of AMPH EROS, 2.5 mg/mL under fasted conditions when chewed and swallowed whole, and demonstrated equivalent peak and overall exposure without apparent food effect. AMPH ER TAB was well-tolerated and consistent with adverse events noted in other amphetamine formulations.