Carolina Lupi Dias, Lisiane Bajerski, Rochele Cassanta Rossi, Ana Maria Bergold and Pedro Eduardo Fröehlich
A selective stability-indicating LC method and a second order derivative UV spectroscopic method (UV-D 2 ) were developed to assay milnacipran in pharmaceutical formulation. The LC method was developed with a Nucleosil C8 analytical column and a mobile phase consisting of acetonitrile, water and triethylamine (at 210 nm). The validation of UV-D 2 (zero-crossing method) was based on recording the second-derivative spectra for milnacipran hydrochloride at 268.5 nm of its solutions in 0.1 N HCl and the parameters specificity, linearity, precision, and accuracy were evaluated to both methods. The linear dynamic range was 20–100μg-mL -1 (R 2 ≥0.999). The validation data showed that both methods are reproducible, providing an accurate (98.5% to 101.6%) and precise (RSD ≤ 1.0%) quantitation of milnacipran in capsules. The methods proposed showed satisfactory results and were statistically equivalent.