Determination of Dissolution in Etidronate Disodium Tablets by Derivatization with UV Spectrophotometry

OBJECTIVE To establish a method for the determination of dissolution in etidronate disodium tablets. METHODS Perform the dissolution test with baskets, using 900mL of water as the dissolution medium, withdraw a quantity after exact 30 minutes and filter. Transfer 2 mL of the successive filtrate, to a 10 mL volumetric flask, add 2 mL of 0.07% solution of copper sulfate and diluted with water to the volume. Determine the absorbance at 233 nm. RESULTS The calibration curve was linear over the range of 16.5-55.0 μg·mL^-1 for etidronate disodium. The average recovery of etidronate disodium was 101.1% with RSD 0.8% (n=9). The dissolution from each tablet was more than 90% of the labeled amount in 30 minutes. CONCLUSION The established method is accurate, simple, and could be used for the determination of dissolution in etidronate disodium tablets.