Development and application of a validated HPLC method for the analysis of dissolution samples of mexiletine hydrochloride capsules

The aim of this work was to develop and validate a simple, efficient, sensitive and selective method for the analysis of dissolution samples of me- xiletine hydrochloride capsules by HPLC without the necessity of any time- -consuming extraction, dilution or evaporation steps prior to drug assay. Sepa- ration was performed isocratically on a 5 µm LiChrospher 60, RP-Select B column (250×4 mm ID) using the mobile phase buffer-acetonitrile (60:42, v/v) at a flow rate of 1.2 mL min -1 and UV detection at 262 nm. The elution oc- curred in less than 10 min. The assay was linear in the concentration range 50- -300 µg mL -1 (r 2 = 0.9998). The validation characteristics included accuracy, precision, linearity, specificity, limits of detection and quantification, stability, and robustness. Validation acceptance criteria were met in all cases (the percent recoveries ranged between 100.01 and 101.68 %, RSD < 0.44 %). The method could be used for the determination of mexiletine hydrochloride and for mo- nitoring its concentration in in vitro dissolution studies.