Intra-individual and inter-individual variation in breath alcohol pharmacokinetics: Variation over three visits

Eleven male and 7 female student subjects underwent serial Breath Alcohol Concentration (BrAC) measurements after being given alcohol as 13% white wine (5.7 ml/kg for males and 4.7 ml/kg for females) in a fasting state on three separate occasions. BrAC versus time curves were constructed for each subject and the values of peak BrAC (C_max), theoretical BrAC extrapolated at zero time (Co), time taken to reach peak (T_max) and rate of elimination (ß) from breath were recorded directly from the curves. Average Intra-individual variation for each individual between the 3 visits (for males and females, respectively) was 5.6% and 8% for Co, 12% and 13% for C_max>, 42% and 37% for T_max and 11% and 13% for ß. Inter-individual variation (for males and females) was 7.5% and 13% for Co, 16% and 15% for C_max, 43% and 46% for T_max and 21% and 15% for ß. Average elimination rates in males (5.3 μg/100 ml breath/h, range 4-7.7) and females (5.6 μg/100 ml breath/h, range 4-7) were not significantly different. Widmark factors calculated by various established mathematical methods were 0.71-0.81 in males and 0.59-0.68 in females, higher than the originally quoted mean experimental levels.