Stability-indicating MEKC method for determination of milnacipran in capsules

A stability-indicating method by micellar electrokinetic chromatography (MEKC) was developed and validated for determination of milnacipran (MNC) hydrochloride in capsules. The MEKC separation was performed in a fusedsilica capillary (40 cm x 50 μm i.d.), 30 kV voltage applied at 30 °C, using as background electrolyte solution 20 mM borate buffer (pH 8.8), 20 mM sodium dodecyl sulfate and detection at 210 nm with a PDA detector. The parameters specificity, linearity (range 20-60 μg.mL), precision, accuracy, and robustness were evaluated. The validation data showed that MEKC method is reproducible, providing an accurate (100.3 % to 101.2 %) and precise (RSD = 1.2 %) to quantify MNC hydrochloride in capsule. The results of accuracy and precision tests were compared to previously validated methods, second order derivative UV spectroscopic (UV-D) and liquid chromatography (LC), by ANOVA and Tukey. The results of accuracy showed non-significant difference between the three methods. For precision, the statistical analysis between MEKC method and LC method showed no significant difference. However, the comparison between MEKC method and UV-D method showed significant difference.