Abstract: | Abstract An accurate and sensitive spectrophotometric method was developed for the determination of risedronate and etidronate in pharmaceuticals. The method was based on oxidation of the studied drugs with potassium persulfate and reaction of the generated orthophosphate ions with molybdovanadate reagent. The produced yellow phosphovanadomolybdate complex was measured at 313 nm. The method was rectilinear in the ranges 0.5–10 and 0.5–8 µg/mL with detection limits of 0.087 and 0.122 µg/mL for risedronate and etidronate, respectively. The method was applied for the determination of the studied drugs in their tablets, and the results agreed with those obtained by the comparison methods. |