Alendronic acid is widely used for the treatment of osteoporosis.
According to the Japanese Pharmacopeia (JP; 17^th edition*), quantification of alendronate sodium hydrate and its related compound should be carried out with a column filled with styrene divinyl benzene copolymer gel and meets following requirements. The method also mentions to pretreat the alendronic acid by adding 9-fluorenylmethyl chloroformate to let the amino groups to form 9-fluorenylmethyloxycarbony (FMOC)-alendronic acid and FMOC-4-aminobutyric acid. The RSpak DS-413 confirmed the requirements were met.

System suitability requirements:
   Resolution of FMOC–alendronic acid and FMOC-4-aminobutyric acid: ≥ 6
   Relative standard deviation (RSD) of six analyses: ≤ 2.0%

*The version at the time of the application acquisition.


Sample : 20 μL
prepared according to JP
1. FMOC-Alendronic acid
2. FMOC-4-Aminobutyric acid

Column    : Shodex RSpak DS-413 (4.6 mm I.D. x 150 mm)
Eluent    : (A) 10 mM Trisodium citrate + 10 mM Na2HPO4 aq. (adjusted to pH 8.0 with H3PO4)
                /CH3CN=85/15
            (B) 10 mM Trisodium citrate + 10 mM Na2HPO4 aq. (adjusted to pH 8.0 with H3PO4)
                /CH3CN=30/70
             Linear gradient ; (B %) 0 to 50 % (0 to 20 min), 50 to 100 % (20 to 35 min), 
                                    100 to 0 % (35 to 36 min), 0 % (36 to 45 min)
Flow rate : 0.8 mL/min
Detector  : UV (266 nm)
Column temp. : 45 °C