Simultaneous determination of metronidazole and diiodohydroxyquine in bulk powder and paramibe compound tablets by TLC-densitometry and HPLC

Abstract

Two sensitive and precise chromatographic methods were developed and validated for simultaneous determination of metronidazole (MTR) and diiodohydroxyquin (DIQ) in pharmaceutical preparation. The techniques adopted for quantification are coupled TLC-densitometry and HPLC. A mixture of chloroform, toluene, ethanol and acetic acid (9:9:1:1, v/v/v/v) was used as the developing solvent for TLC-densitometry. A mixture of methanol and acetonitrile, (96:4, v/v) was used as a mobile phase for HPLC at 0.6 mL min-1 flow rate and UV detection at 254 nm. Linearity was obtained in concentration range of 0.5-10 μg spot-1 for DIQ and 1-20 μg spot-1 for MTR applying TLC-densitometry and 0.005-0.5 mg mL-1 for DIQ and 0.01-0.5 mg mL-1 for MTR applying HPLC. The selectivity of the proposed methods was checked using laboratory prepared mixtures. The proposed methods were successfully applied to the analysis of MTR and DIQ in their mixture and in pharmaceutical dosage forms without interference from other additives.