3228 Adrjanowicz et al. Analyte label imp. 1 imp. 2 imp. 3 imp. 4 imp. 5 Furosemide imp. 6 imp. 7 imp. 8 imp. 9 imp. 10 0.26 0.35 0.76 0.85 0.92 1.00 1.10 1.40 1.42 1.49 1.64 Fig. 6 Overlaid chromatograms of crystalline furosemide (black) and that cryomilled alone for 60 min (blue), with inulin (navy blue) and with PVP (green). diffractograms (not shown herein). Next, the purity of the outcome materials was tested by UPLC technique. The chromatograms are presented in Fig. 6, and a comparison of the impurities profile is given in Table III (impurities below 0.05% are not reported). Similarly to furosemide cryomilled alone, in the co-ground furosemide-PVP and furosemide-inulin mixtures, several impurities were detected. Remarkably, a significant increase in the amount of Imp.1 with relative retention time of 0.26 was reported (respectively, 3.44% and 5.17% for furosemide-inulin and furosemide-inulin mixtures). Again, as a consequence of cryogenic mechanical treatment, the purity of the systems is substandard. Based on the above results, we can conclude that grinding of the furosemide with the selected polymer or polysaccharide for a studied weight ratio won’t bring chemical stabilization of studied pharmaceutical. The Table III Comparison of Impurity Profiles of Furosemide Prepared in Different Ways Relative retention time Furosemide crystalline Furosemide (cryomilled Furosemide cryomilled for 60 min) with inulin 1:1 ratio Amount of analyte [%] Furosemide cryomilled with PVP 1:1 ratio 0.05 – – – – 99.95 – – – – – Total impurities 0.05 1.68 0.06 – – 0.06 97.82 – 0.06 0.23 – 0.09 Total impurities 2.18 3.44 0.19 0.06 – 0.12 95.69 0.05 0.05 0.25 – 0.15 Total impurities 4.31 5.17 0.26 0.06 0.16 0.07 93.92 0.08 – 0.08 – 0.20 Total impurities 6.08