Quantitative analysis of ursodeoxycholic acid and related compounds in drug substances and dosage forms by HPTLC with scanning densitometry

An high-performance thin-layer chromatographic (HPTLC) method on silica gel, with chloroform - acetone - acetic acid (70 + 20 + 1, v/v) as mobile phase, has been used for the qualitative and quantitative determination and purity control of ursodeoxycholic acid in bulk samples and pharmaceutical dosage forms. Detection by post- chromatographic color reaction was achieved by spraying with 20% m/v phosphomolybdic acid in 95% ethanol and then heating the plate at 105 degrees C for 5 min. Spots were quantified by scanning at lambda = 710 nn. The potential impurities are well separated from ursodeoxycholic acid and from each other with the exception of chenodeoxycholic and deoxycholic acids which overlap. Detection limits at a signal-to-noise ratio of 2:1 were below 15 ng per spot, Linearity, reproducibility, and percentage recovery of ursodeoxycholic acid from dosage forms are reported. Reliable results were obtained.