Method Abstract 328


Alendronic Acid or Alendronate Sodium is a bisphosphonate drug that inhibits osteoclast-mediated bone resorption. Biphosphates work by binding to the bone and preventing calcium from being removed by osteoclasts. This drug is used to prevent and treat osteoporosis as well as several other bone diseases. Alendronate Sodium is sold as tablets or solutions, alone or in combination with Vitamin D.

Since Alendronic Acid has no chromophore, post-column derivatization is employed to produce a fluorescence derivative.

This abstract describes selective and sensitive analytical method for the analysis of Alendronic Acid in pharmaceutical tablets. Simple sample preparation and fast analysis time allow for using this method in high throughput environments.


Analytical Conditions

Column: Anion-exchange, 4.1×150 mm
Temperature: 45 ºC
Flow Rate: 1.0 mL/min
Mobile Phase: Sodium Nitrate, 50 mM, pH 7.8 / Methanol (60:40)

Post-column Conditions

Post-column System: Pinnacle PCX
Reactor Volume: 0.5 mL
Temperature: 70 ˚C
Reagent: OPA (300 mg), Thiofluor (2g), 30 % Brij 35 (3 mL) in 950 mL of OD104
Reagent Flow Rate: 0.5 mL/min
Detection: FLD λex: 330 nm, λem: 465 nm

Sample Preparation:

Crush 1 tablet and mix with water. Use enough water to get Alendronate Sodium concentration between 300 and 1000 μg/mL. Heat the solution using a water bath to 65 ºC and stir for 30 min. Filter liquid portion through 0.45 μm filter. Put filtrate in HPLC autosampler vial and inject 10 μL.


Calibration curve for analytical range 100-1000 ppm                  Chromatogram of Fosavance® tablet (Alendronate sodium 70 mg, Vitamin D 2800 IU)