A glass is disclosed that is particularly suitable as pharmaceutical packing medium and as a chemically pre-stressable glass comprising at least the following components (in mol-% on oxide basis): 64-77 SiO2, 5-14 Al2O3, 4-12 Na2O, 1-12 CaO, 0-14 MgO, 0 -2 ZrO2, 0-4.5 TiO2, wherein the ratio Al2O3/Na2O≥1, wherein the ratio Al2O3/CaO≥1.5, and wherein the total content SiO2+Al2O3