In Vivo Data Analysis
Published data of plasma concentration profiles of Singulair® granules (4 mg) co-administered with formula or applesauce to different infant subgroups (formula: 1 to 3 months; applesauce: 3 to 6 months and 6 to 24 months) were digitalised with WebPlotDigitizer® v4.1 software (USA) (16,17,19,23).
The corresponding in vivo drug absorption profiles were obtained after deconvolution of the oral data using the Wagner-Nelson equation (Eq. 1) (Excel, Microsoft®) (24).1 %absorbed=AtA∞×100=At+k∫τ=0tAτdτk∫τ=0∞Aτdτ×100
where A(t) is the amount of drug in the system at time t and k is the first-order elimination rate constant (24). The elimination rate constant was obtained from the slope of the terminal logarithmic concentrations of the in vivo montelukast oral data.
The linear trapezoidal method was used to calculate the area under the curve of each in vivo % drug absorbed over 4-h profile (AUC0–4 h in vivo).