Oral bioavailability of phenobarbital: a comparison of a solution in Myvacet 9-08, a suspension, and a tablet.

PURPOSE: A three-way crossover study with seven healthy male volunteers was conducted to determine the relative bioavailability of phenobarbital after single dose administration of 100 mg of phenobarbital as oral solution in Myvacet 9-08, and as a suspension, compared with a 100 mg phenobarbital tablet.

MATERIALS AND

METHODS

At 4-week intervals each subject received the solution in Myvacet 9-08, the suspension and the tablet in randomized order. Blood samples were collected for 48 h after each dose for analysis of phenobarbital. From the individual serum concentration-versus-time curves Cmax and Tmax were determined and AUC0-48 was calculated.

RESULTS

All three oral dosage forms of phenobarbital are bioequivalent. No significant differences in Tmax were observed.

CONCLUSION

The oral solution in Myvacet 9-08, and the suspension of phenobarbital proved to be bioequivalent to a tablet.