Background:
Alendronate sodium is a common clinical osteoporosis drug for postmenopausal
women; its determination is very important. However, there is no absorption of chromophores or
fluorophores in the molecule, therefore, their direct determination is a challenge. Thus, establishing a
common and direct method is very inspiring.
Methods:
According to the direct determination of alendronate sodium through the formation of a complex
between alendronate sodium and divalent copper ion by capillary electrophoresis with ultraviolet
detection, the dissolution profile of alendronate sodium tablet was established. The dissolution curves
obtained from high-performance liquid chromatography method involving derivatization with 9-
fluorenyl methylchloroformate and capillary electrophoresis with ultraviolet detector were found to be
highly similar. Underivatized alendronate sodium can be determined by the capillary electrophoresis
method.
Results:
Optimum conditions were as follows: background electrolyte including 25 mM CuSO4 at pH
4.59, 5 s injection time, 18 kV applied voltage, and 240 nm detected wavelength. Method validation
indicated good linearity (r2>0.9993), precision of migration time with a relative standard deviation <1.5
% for intra-day and <3.6 % for inter-day, precision of peak areas <2.3 % for intra-day and <5.0 % for
inter-day, limits of detection (0.01 μg/mL), limit of quantification (0.04 μg/mL) and recovery (90.6 %-
109.0 %).
Conclusion:
The proposed capillary electrophoresis method has been proved to be simpler, faster and
more convenient to test dissolution profile of alendronate sodium tablet than that of high performance
liquid chromatography.
