Deconvolution method for assessing the absorption of a drug with reversible metabolic pathways.

A method has been established to determine the input rate for a drug with reversible metabolic processes. This method is based on linear system properties without imposing a compartment model for describing the disposition of the drug and the metabolite and their interconnections. The solution is a deconvolution method in N-dimensional space. A general solution has been obtained for calculating the parameters needed to describe the input function. The specific solution for a staircase input function (point-area deconvolution) is explicitly derived. Using a staircase input function is not a robust method and can give negative input values when applied to simulated data sets with a large amount of variability. This suggests the need for more robust functional forms to describe the input function.