Spectrophotometric determination of tranexamic acid using vanillin

A new spectrophotometric method has been examined for the determination of the tranexamic acid （TA） by derivatization with vanillin （VAN）. The molar absorptivity of TA was calculated 25 160 L·mol-1·cm^-1 at λmax 354 nm and obeyed the Beer＇s law within 0.5-2.5 μg·mL^-1. The color reaction was highly stable and did not show any change in absorbance up to 24 h. The method was applied for the analysis of TA from capsules, injections and tooth pastes. The amounts of TA found in capsules, injections and tooth pastes of various pharmaceutical companies were observed with 249.0-250.9 mg/capsule, 249.3-250.7 mg/injection and 0.048%-0.049% in tooth pastes with relative standard deviation （RSD） 0.2%-5.0% （n = 3）.