LC method for quantitative determination of ciprofloxacin in ophthalmic ointment

Abstract

The present study aimed to validate an analytical method for the quantification of ciprofloxacin in ophthalmic ointment by high performance liquid chromatography. The chromatographic separation of ciprofloxacin hydrochloride was achieved on a C18 reverse-phase column (Hypersil Gold (4 x 250 mm, 5 µm) using UV detection at 278 nm. The optimized mobile phase consisted of a mixture of 0.025 M phosphoric acid with a pH previously adjusted with triethylamine to 3.0 and acetonitrile (85:15, v/v). The parameters specificity, linearity, precision, accuracy and robustness were evaluated according to official guidelines. The purposed assay showed to be specific and the linearity was proved in a range of 10 - 50 μg.mL-1. The RSD values obtained during precision assay (inter-day RSD = 1.38%) indicated the method reproducibility, and the accuracy testing showed good results from recovery test. Robustness assay was complementary and showed that the purposed method is adequate for drug quantitation in commercial samples. No interference from any components of the pharmaceutical dosage forms was observed.