This article compares the stability test results of ZORBAX Eclipse XDB-C8 and Symmetry-C8. The ZORBAX particle technology results in an extremely strong and dense silica support that dissolves more slowly at higher pH than xerogel particles used in Symmetry column packings. The extra dense bonding of ZORBAX XDB-C8 helps to shield the silica support at intermediate pH and decreases loss of chromatographic performance compared to Symmetry C8. By combining dense, durable particles, extra-dense bonding, and double endcapping, ZORBAX Eclipse packings (e.g., XDB-C8) have increased lifetime compared to Symmetry columns.