Figure 8. Photostability percentages in the UVB range by protocol 1 (PMMA), protocol 2 (cuvette) and HPLC

With some products (C4, C2, C3, H1, C7 and C6), HPLC method and protocol 1 gave very different results (> 10% difference). Conversely, the results obtained by HPLC and protocol 2 were similar for 10 products, whether in the UVB or UVA range.