Optimized Chromatographic Determination of Naphazoline and Chlorpheniramine in Eye/Nose Drops Using Cation-exchange...

A simple and efficient liquid chromatographic method has been developed and validated for the simultaneous determination of naphazoline and chlorpheniramine in eye/nose drops, in presence of naphazoline degradation product and naphthalene acetic acid (NAPD). The separation was achieved within 6.0 min, employing a mixture of 53.5% v/v water-acetonitrile containing 78.70 mM/L sodium dihydrogen orthophosphate adjusted to pH 5.30 as isocratic mobile phase, pumped at 1.0 mL/min through a strong cation-exchange column (10 μm particle size), the analytes were monitored at 230 nm. Statistical experimental designs and graphic representations (response surface methodology) were used for optimizing the chromatographic separation. The linearity plots were linear over concentration range up to 125% of the analytes nominal concentrations (100%) with regression coefficients (r) > 0.99, method's accuracy (RSD < 2.0%), repeatability and intermediate precision (RSD < 2.0%) were verified. System suitability parameters were also within the acceptable range. The validated method was successfully employed for the routine analysis of eye/nose drops.