RELATIVE BIOLOGIC AVAILABILITY AND PHARMACOKINETICS OF ALBUTEROL PREPARATIONS IN HEALTHY CHINESE

The authors' goal was to study the biologic availability and pharmacok inetics of two different formulations of controlled-release (CR) table ts of albuterol. A two-way, cross-over biologic availability study was performed with 20 healthy male volunteers to evaluate the relative bi ologic availability of two CR tablets of albuterol versus two differen t formulations of immediate-release (IR) albuterol tablets. Albuterol concentrations in plasma were measured using an HPLC procedure. Each p atient subject received a 4.8-mg CR tablet every 12 hours for 6 days a nd a 4.8-mg IR tablet every 8 hours for 6 days. Tests of single doses and steady state were assayed far CR and IR albuterol tablets. The mea n C-max and t(max) for two CR tablets given after a single dose were 7 .3 +/- 1.5, 7.9 +/- 1.4 mu g . L-1 and 4.6 +/- 0.8, 4.8 +/- 0.5 hours, respectively. The C-max and t(max) for two IR tablets given after it single dose were 12.5 +/- 1.3, 15.3 +/- 2.3 mu g . L-1 and 1.3 +/- 0.4 , 1.6 +/- 0.4 hours, respectively. The relative biologic availability of two CR albuterol tablets were 106.0 +/- 6.2% and 109.8 +/- 9.0%, re spectively. Administration of CR albuterol twice a day provides an alt ernative to administration of IR albuterol three or four times a day.