Gabapentin Extended Release Tablets in Healthy Subjects Under Fed Conditions: A Randomized, Open-Label, Two-Treatment, Two-Period, Two-Sequence, Single Dose, Crossover, Comparative Bioavailability Study

Gabapentin is effective for treating post-herpetic neuralgia and neuropathic pain by stabilizing nerve activity through blocking calcium channels and reducing neurotransmitter release. Gabapentin is available in immediate-release (IR) and extended-release (ER) formulations. A comparative bioavailability study was conducted between Gabapentin ER 600 mg tablets once-daily (OD) (Gabantin ® GRS) [Test (T)] (manufactured by Sun Pharmaceuticals Industries Limited), and Gabapentin Tablets 600 mg OD (Gralise ® ) [Reference (R)] (distributed by Almatica Pharma LLC) in healthy human male adults under fed conditions. In this open-label, balanced, randomized, crossover study each subject received a 600 mg single dose of either T or R in Period 1, followed by crossover treatment in Period 2, with a washout period of 12 days in-between. Pharmacokinetic parameters, including C max , AUC 0-t , and AUC 0₋∞ , were assessed. Safety was monitored through treatment-emergent adverse events (AEs). All 24 enrolled subjects completed the study. The test formulation demonstrated comparable pharmacokinetic profile to the reference product, meeting the criteria for bioequivalence within acceptable limits (0.80–1.25). The percentage ratio for T vs R product was 0.9171 (90% confidence interval [CI] 0.826–1.0183) for AUC 0-t , 0.9191 (90%CI 0.8279–1.0203) for AUC 0-∞ and 0.9135 (90%CI 0.8324–1.0026) for C max . Plasma concentration-time profiles were similar. One AE of fever was reported after administration of T; no serious adverse event was reported. Gabantin ® GRS 600 Tablet ER OD of Sun Pharma had a similar pharmacokinetic profile and was bioequivalent to Gralise ® in healthy subjects under fed conditions with good safety and tolerability profiles.