HPLC Separation of Alendronic, Ibandronic, Etidronic Acids

Dronic acids are bisphosphonates that differ in their alkyl chains. Alendronate (Fosamax) marketed alone is used for osteoporosis and other bone diseases. It is also combined with Vitamin C (Fosavance). A short, 50 mm Primesep SB column separates alendronic, ibandronic, and etidronic acids. The HPLC separation uses a mobile phase of water, acetonitrile (MeCN, ACN), trifluoracetic acid (TFA) or ammonium formate and evaporative light scattering detection (ELSD) at 80°C.