Albuterol extended-release products: a comparison of steady-state pharmacokinetics.

A new extended-release formulation of albuterol, Volmax, was developed based on the oral osmotic drug delivery system. Proventil Repetabs, another extended-release formulation of albuterol, is a repeat-action tablet. The steady-state pharmacokinetic profile of Volmax 8 mg orally every 12 hours for 3 days was compared with that of Proventil Repetabs 8 mg orally every 12 hours for 3 days in a randomized, two-way, crossover study in 23 healthy men. Results were determined for both daytime and nighttime dosing intervals. Volmax demonstrated significantly less peak-trough fluctuation during both dosing intervals than Proventil Repetabs (p less than 0.05). Peak plasma concentrations were higher and occurred earlier with Proventil Repetabs. There were no significant differences between the two formulations with respect to reported adverse experiences. Volmax exhibited a more controlled release of albuterol during both daytime and nighttime dosing intervals than Proventil Repetabs.