Adenosine is an endogenous nucleoside occurring in all cells of the body. It is chemically 6amino-9-beta-D-ribofuranosyl-9-H-purine and has the following structural formula:

C₁₀H₁₃N₅O₄      267.24

Adenosine is a white crystalline powder. It is soluble in water and practically insoluble in alcohol. Solubility increases by warming and lowering the pH of the solution.

Each Adenoscan vial contains a sterile, non-pyrogenic solution of adenosine 3 mg/mL and sodium chloride 9 mg/mL in Water for Injection, q.s. The pH of the solution is between 4.5 and 7.5.