2.3. Controlled Release Experimental Protocol

Following the batch manufacture through an injection mold process, RhB-loaded polymer devices (PCL and PLA) were tested for their release rate of RhB in PBS in vitro. Devices were submerged in 150 mL of PBS that was maintained at 37 °C in an incubator (VWR^®/Gravity Convection Incubators). The PBS sink solution was continuously mixed via a magnetic stir bar at 250 rpm. Samples of 2.5 mL sink solution were removed with replacement at the given time interval for the experiment (hourly or daily). The 2.5 mL samples were analyzed through UV–Vis spectroscopy (Perkin Elmer^®/LAMBDA 365r) at a wavelength of 553 nm [36,44]. Several different experiments were conducted following this common protocol or with minor modifications based on experimental needs as described below.