Metoprolol-eudragit microcapsules: pharmacokinetic study using convolution approach

The objective of this study was to employ convolution approach for the calculation of blood drug levels for various release types (1:1, 1:1.5, and 1:2, drug:polymer) of metoprolol tartrate microparticulate formulations from in vitro drug dissolution profiles. Using USP 2007 dissolution apparatus II, dissolution testing was carried out by employing sequential pH change method with and without 0.5 % soudium lauryl sulphate, surfactant. The values of derived pharmacokinetic parameters like Cmax (Maximum blood drug concentration), Tmax (Time needed to reach maximum blood drug concentration), and AUC (area under blood drug concentration curve) from the predicted drug concentration in blood were amazingly comparable to that calculated from the corresponding human in vivo data as stated in literature. As per conclusion, convolution approach is a useful analytical tool for computing drug concentration in blood as well as for evaluating product quality. Colegio de Farmacéuticos de la Provincia de Buenos Aires