Comparison of a novel fast-dissolving acetaminophen tablet formulation (FD-APAP) and standard acetaminophen tablets using gamma scintigraphy and pharmacokinetic studies

Abstract

Context: Acetaminophen (paracetamol, APAP) is widely used to relieve mild-to-moderate pain and reduce fever. Absorption of the drug can be impacted by dosage form; this may have implications for pain relief in some individuals, potentially accounting for suboptimal efficacy in analgesia. Objective: To assess the disintegration and dissolution of a new fast-dissolving acetaminophen tablet formulation (FD-APAP) and the impact on pharmacokinetic and pharmacodynamic parameters. Materials and methods: Two randomized, single-center, open-label, single-dose, two-way crossover studies in healthy subjects to compare FD-APAP (2× - 500mg tablets) with standard acetaminophen (2× - 500mg tablets). Gamma scintigraphy was used to assess tablet disintegration (Study 1, N=24), and plasma profiles were evaluated in the fasted state (Study 2, N=40). Results: In Study 1, the mean time to complete disintegration (12.9 vs. 69.6min, P<0.0001) and onset of disintegration were both significantly faster with FD-APAP than with standard acetaminophen (P<0.0001). For Study 2, median Tmax was significantly faster for FD-APAP (0.50 vs. 0.67h, P<0.01) and AUC0-30 min was significantly greater (4.51 vs. 2.74, P<0.05). AUC0-t and AUC0-inf were comparable between the two study treatments. Discussion: Despite the absence of comparative clinical data, the FD-APAP formulation may be expected to overcome some of the issues associated with the slow and variable absorption of standard acetaminophen tablet formulations, improving therapeutic outcome and avoiding the need to switch to alternative therapeutic options. Conclusion: Compared with standard acetaminophen, the FD-APAP formulation results in significantly faster onset of disintegration and more rapid absorption. © 2011 Informa Healthcare USA, Inc.