RESUMEN
PURPOSE: One-capsule, once-daily valbenazine is approved for tardive dyskinesia and under evaluation for chorea associated with Huntington's disease, conditions in which patients often experience dysphagia. In vitro studies were conducted to assess the suitability of crushing the contents of valbenazine capsules (40 and 80 mg) for mixing with soft foods or liquids or administration via a gastrostomy tube (G-tube). METHODS: In study 1, the dissolution of whole valbenazine capsules and crushed capsule contents were measured serially for 1 hour. In study 2, valbenazine recovery was evaluated after crushed contents were mixed with soft foods, buffer solutions (pH range, 1.2-6.8), and fed-state simulated gastric fluid. In study 3, valbenazine recovery was evaluated after crushed contents were dispersed in water and delivered via a G-tube. In studies 2 and 3, acceptable valbenazine recovery was 90% to 110%. FINDINGS: Study 1 indicated rapid and complete drug release for whole valbenazine capsules and crushed capsule contents, with similar release at 10 minutes (whole, 94%-99%; crushed, 98%-100%) and 60 minutes (whole, 101%-103%; crushed, 101%-102%). Study 2 found acceptable valbenazine recovery within 2 hours of adding crushed capsule contents to tested foods, buffers, or fed-state simulated gastric fluid (recovery, 92%-102%). Study 3 found acceptable valbenazine recovery when crushed contents were added to cold or hot water and delivered via G-tube, with a water cup rinse to capture residual contents (recovery, 91%-97%). IMPLICATIONS: These studies indicate the potential viability of valbenazine formulation(s) that can be added to soft foods or liquids or delivered via G-tube. Such formulations will be important for individuals who require treatment with a vesicular monoamine transporter 2 inhibitor but cannot swallow whole pills.