In Vitro/in Vivo relationship of gabapentin from a sustained-release tablet formulation: A pharmacokinetic study in the beagle dog

Abstract

The aim of this study was to examine the in vitro/in vivo relationship of the drug release behavior of a sustained-release formulation of gabapentin. The immediate-release formulation was used as the reference formulation. The dissolution test was employed using pH 1.2, 4.0, or 6.8 buffer solution, or water, to determine the in vitro release behaviors of gabapentin tablets. Gabapentin was released completely within 1 h from the immediate-release tablet and released for 12 h from the sustained-release tablet. A single dose (600 mg) of each formulation was orally administered to four beagle dogs under fasted conditions, and the pharmacokinetic parameters were calculated. Although the sustained-release tablet did not disintegrate and had slow drug release characteristics, it showed similar pharmacokinetic parameters to the immediate-release tablet, which rapidly disintegrated and showed fast drug release. Thus, the in vivo release of gabapentin did not correlate with in vitro release of drug.

QbD-Oriented Development and Characterization of Effervescent Floating-Bioadhesive Tablets of Cefuroxime Axetil

“…The extent of drug absorption, as revealed by the AUC 24h values, was also found to be significantly higher from the optimized formulation than from the marketed formulation (i.e., 1.78-fold; p<0.001). Such enhancement in the bioavailable fraction is in consonance with several of previous reports on GR formulations (1,8,38,39). Overall, the studies construe appreciable extension in drug absorption profile when formulated as floating-bioadhesive tablets, ostensibly owing to the increase in gastric residence time by virtue of its floatation and bioadhesion characteristics.…”

Pharmacokinetics of oral gabapentin in greyhound dogs

“…Previous studies have examined the pharmacokinetics of gabapentin in Beagles at supra-therapeutic doses (Vollmer et al, 1986; Radulovic et al, 1995; Rhee et al, 2008). The purpose of this study was to assess the pharmacokinetics of gabapentin in dogs at clinically relevant doses.…”

Assessment of the effects of adjunctive gabapentin on postoperative pain after intervertebral disc surgery in dogs

“…Therefore, in dogs mean elimination half‐life is very short (3.1 to 3.4 hours) (Vollmer et al. 1986; Rhee et al. 2008; Kukanich & Cohen 2011), requiring frequent dosing to obtain stable and effective GBP concentrations for reducing seizure activity.…”

“…In contrast to other species, where GBP is mainly excreted via the kidney, in dogs GBP is partly metabolized in the liver (34%) (Radulovic et al 1995). Therefore, in dogs mean elimination half-life is very short (3.1 to 3.4 hours) (Vollmer et al 1986;Rhee et al 2008;Kukanich & Cohen 2011), requiring frequent dosing to obtain stable and effective GBP concentrations for reducing seizure activity. Therefore, GBP is mainly used as an add-on drug in the treatment of canine epilepsy.…”