Abstract:
OBJECTIVE To establish an HPLC method for simultaneous determination of three bacteriostatic agents (ethylparaben, thimerosal, benzalkonium chloride) in bendazac lysine eye drops. METHODS The analysis was performed on Kromasil C
18 (4.6 mm×250 mm, 5 μm) with the mobile phase consisting of acetonitrile(A)-0.1% triethylamine(B)(adjusted to pH 3.0 by phosphoric acid) in gradient mode: 0-2 min, B 50%; 2-17 min, B 50%→90%; 17-29 min, B 90%; 29-30 min, B 90%→50%. The detection wavelength was 262 nm with injection volume of 20 μL and column temperature of 40 ℃. RESULTS ethylparaben, thimerosal and benzalkonium chloride showed good linearity(r>0.999) in the range of the test concentration of 0.07-1.32, 0.38-9.51, 3.26-32.6 μg·mL
-1. The average recoveries of the method were in 99.0%-100.3%. CONCLUSION The method is sensitive, rapid and accurate with good repeatability, which can be used for rapid screening and determination of the content of bacteriostatic agents in bendazac lysine eye drops.