Compositions comprising thrombin and collagen and methods of preparation thereof are disclosed herein. In one embodiment, a composition comprises thrombin and collagen in an aqueous buffer solution, wherein the buffer solution includes at least one of a first compound represented by Formula I: R1—C(O)—O−M+, wherein R1 is —CH3, —CH2CH2C(O)OH, or —CH2CH2C(O)O−M+, and wherein M+ is a monovalent ion or a second compound represented by Formula II: R2-C(O)—O−M2+-O—C(O)—R2, wherein R2 is —CH3 or —CH2CH3, and wherein M2+ is a divalent ion. In one embodiment, the buffer solution includes sodium acetate, calcium propionate, and sorbitol.
