Meal‐Dependent Absorption of Enteric‐Coated Sodium Valproate

Abstract

The effect of meals on valproic acid (VPA) absorption from an enteric coated (EC) formulation was investigated. In study I, 6 adult normal volunteers received a single 500 mg dose of Na valproate in randomized treatments: fasting (A), with a meal (B) or 3 h after a meal (C). There were significant differences between treatments in the latency period (Lp) defined as the time during which measured concentrations of VPA were less than 1 .mu.g/ml. Lp values for treatments A, B and C were: 1.67 .+-. 1.25 h, 6.75 .+-. 3.98 h and 7.63 .+-. 3.15 h, respectively. In study II, 6 subjects (5 from study I) received in a randomized fashion a 400 mg i.v. bolus dose of VPA and a 500 mg EC VPA tablet, 3 h after a meal. The mean Lp value was 8.1 .+-. 1.6 h and the mean bioavailability was 100%. Clearance, volume of distribution and half-life values obtained after i.v. dosing were comparable to literature values. Food intake apparently delays but does not decrease the extent of absorption of VPA from an enteric coated formulation.