I would imagine that it is fine but there's only one way to find out. I guess sedimentation could happen in 2 years but from what I've read it's an acid of silicone so maybe not. Give a shake any way.
Silicic acid, (SiO2) from wikipedia..."Research of the correlation of aluminium and Alzheimer's disease has included the ability of silicic acid in beer to reduce aluminium uptake in the digestive system as well as to increase renal excretion of aluminium 
Choline-stabilized orthosilicic acid (ch-OSA) is a dietary supplement. It has been shown to prevent the loss of tensile strength in human hair; to have a positive effect on the surface and mechanical properties of skin, and on the brittleness of hair and nails; to abate brittle nail syndrome; to partially prevent femoral bone loss in aged ovariectomized rats; to increase the concentration of collagen in calves; and to have a potentially beneficial effect on the formation of collagen in the bones of osteopenic women."