2.3.5. In Vitro Release Studies

The provided samples were immersed in beakers full of 15 mL of PBS medium liquid (pH 8.5) and placed in an incubator at 50 rpm and 37 °C. Every single 60 min, a 4.0 mL aliquot of the solution was taken out, and a 4.0 mL of a new buffer was substituted to maintain the original volume after every single withdrawal. The concentration of the catechin released was determined using a UV–vis spectrophotometer. The amount of catechin was measured by interpolation from the catechin standard curve at l = 317 nm.