Pharmacokinetics of Gabapentin in a Novel Gastric‐Retentive Extended‐Release Formulation: Comparison With an Immediate‐Release Formulation and Effect of Dose Escalation and Food

The objectives of the 3 phase I studies described herein were (1) to compare the pharmacokinetics of gabapentin delivered from a novel gastric-retentive dosage form vs an immediate-release formulation, (2) to assess the dose proportionality of the gastric-retentive extended-release formulation, and (3) to determine the effect of food on the pharmacokinetics of gabapentin delivered from this formulation. The time to reach maximum plasma concentration (t max ) was extended for gabapentin delivered from the gastric-retentive extended-release formulation compared with the immediate-release formulation. A dose-related increase in both the maximum plasma concentration (C max ) and the area under the plasma concentration-time curve (AUC) was observed as thegabapentin dose increased from 600 to 2400 mg. Fed status and increased fat content delayed t max and enhanced C max and AUC in proportion to the fat content. The pharmacokinetics of gabapentin delivered from this extended-release formulation allows a reduced dosing frequency while maintaining bioavailability and possibly diminishing the occurrence of adverse events attributable to a slower increase to the peak concentration compared with the immediate-release dosage form.