False-color SRS images of a film with 20% drug loading, together with the correla ve grey-scale confocal reflec on images of exactly the same areas, are presented in Figure (right). At each me point, these images are complemented in the same figure with a coefficients plot on the le side of the figure, containing the chemically-specific SRS CLS coefficients (represen ng drug, polymer and buffer), as well as the correla ve reflec on coefficients (from exactly the same rectangular area). In the interpreta on of the data in Figure , first the chemically-specific SRS data is considered, followed by the correla ve confocal reflec on data. The false color SRS image of the dry film (Figure , 0 minutes) was an almost uniform shade of green, consistent with a single-phase homogeneous film rich in PVPVA, and the film-air interface was sharp. The SRS coefficients measured from the rectangle in the image together with minimal standard devia ons (not visible), are consistent with a homogenous distribu on of 20% drug and 80% polymer across the film.