Bioequivalence study for diazepam commercial tablets in psychiatric patients

The bioequivalence of three different commercial diazepam tablets (5 mg) using the innovator product (Valium, Roche) as a reference was evaluated in eight psychiatric patients, following a multiple-dose regimen (5 mg t.i.d.). Each patient received the four treatments sequentially according to a Latin square design, with balance for first residual effect. Blood samples were taken once the steady state of the drug had been reached, and the plasma levels were determined using a HPLC method. No statistical differences were found in diazepam steady-state levels after the administration of the four formulations, indicating that they could be considered equivalent.