The SRS false color images and coefficients plots confirm that drug-polymer phase separa on also occurs at the 60% drug loading, though somewhat more subtly in the SRS false color images. A con nuous drug enriched surface layer is apparent already within 1 min of buffer exposure (visible in the 1 min SRS false color plot and SRS coefficient plot, Figure ), accompanied by a few encapsulated polymer-rich pockets within this surface layer (1 min SRS false color image, Figure ). These pockets gradually increases in size over the dura on of the experiment. However unlike at the 40% drug loading, none of the imaged polymer pockets appear to break free from the con nuous drug rich network at any point. Within the film, the reflec on images clearly demonstrate bulk phase separa on from the 1 min mepoint onwards and its con nued propaga on in the gel phase, trailing the water penetra on front by approximately 3 µm at 1 min; this gap had expanded to approximately 44 µm a er 30 min. The chemically-specific SRS false-color images reveal that this bulk phase separa on within the film is characterized by a disperse polymer-rich phase within the con nuous drug-rich phase.