Plasma Concentrations Of Diazepam Research Articles

Determination of bioavailability of diazepam in various formulations from steady state plasma concentration data.

The plasma concentrations of diazepam (Valium, Roche Labs., Nutley, N. J.) and its maior metabolite, N‐desmethyldiazepam, after treatment with 5 mg. oral doses three times a day were investigated in 7 subfects. There was a twofold variation in the steady‐state concentrations between subiects. The plasma half‐lifes of diazepam varied between 26 and 53 hours. A crossover study with an evaluation of the bioavailability of 3 manufacturers' tablet products and a suspension of diazepam was included in the investigation. The tablets gave similar intraindividual plasma levels while the suspension showed lower values during steady state, thereby indicating incomplete absorption.