Visit 1
Visit 2
Intra-individual
variability
  T4 T8 T12 T4 T8 T12 (%)
Urine volume (mL) 453±272 287±117 331±172 373±179 289±207 384±220 10.5
USG (gmL-1) 1.019±0.009 1.021±0.005 1.018±0.006 1.020±0.007 1.019±0.006 1.016±0.006  
Concentration ofsalmeterol (ngmL-1) 0.36±0.19 0.15±0.09 0.10±0.07 0.41±0.28 0.14±0.07 0.08±0.03 43.0
Excretion ofsalmeterol (µg) 0.13±0.04 0.04±0.03 0.03±0.02 0.13±0.06 0.04±0.03 0.03±0.02 12.6
Concentration of a hydroxysalmeterol-(ngmL-1) 2.33±1.43 1.61±1.39 0.68±0.59 2.50±1.49 2.19±1.29 0.92±0.37 43.7
Excretion of α-hydroxysalmeterol(µg) 0.86±0.24 0.39±0.23 0.23±0.21 0.99±0.48 0.55±0.34 0.30±0.16 21.8
Table 1: Urine excretions and urine concentrations of salmeterol and α-hydroxysalmeterol when uncorrected for USG in seven subjects during the first and second visit after inhalation of 100 μg salmeterol. T4: Four hours after administration, T8: Eight hours after administration, T12: Twelve hours after administration. Intra-individual variability is expressed as the mean intra-individual %CV between visits one and two.