The analysis of the ASD with 80% drug loading is presented in Figure . The false color SRS image of the dry film (0 min) was an almost uniform shade of pink, consistent with a single-phase homogeneous film rich in PVPVA, and the film-air interface was sharp. The SRS coefficients extracted from the rectangle in the image together with minimal standard devia ons (not visible), are consistent with a homogenous 80% and 20% drug and polymer loading across the film, respec vely, with a sharp film-air interface. In contrast to all the ASDs with lower drug loadings, but consistent with the pure RTV film (Figure ), this matrix appears essen ally inert with no obvious chemical or physical changes to the film for the dura on of the experiment (up to 30 min), including water penetra on, swelling and phase separa on, and no drug or polymer release into the buffer.