Rapid determination of alendronate to quality evaluation of tablets by high resolution 1H NMR spectroscopy

Determination of alendronate is crucial to routine quality control of alendronate tablets. However, tedious sample treatment processes such as derivatization were generally required by chromatographic separation of alendronate as its high polarity and no chromophore in the molecular structure. Here, we describe the use of 1H NMR for the quantification of alendronate sodium in tablets. Linearity, recovery, selectivity and sensitivity of the assay were validated to be satisfactory with quick sample preparation and acquisition. The contents of alendronate sodium in tablets from five manufacturers were determined, the results showed that all assayed tablets fell within the range of 90.0-110.0% of the label claim and the relative standard deviation was less than 6.0%. The method was also successfully employed for alendronate tablet dissolution assay in this study.