RAPID SIMULTANEOUS DETERMINATION OF ALISKIREN AND HYDROCHLOROTHIAZIDE FROM THEIR PHARMACEUTICAL FORMULATIONS BY MONOLITHIC SILICA HPLC COLUMN EMPLOYING EXPERIMENTAL DESIGNS

A simple, rapid, precise, and stability-indicating HPLC method was developed and validated for simultaneous determination of hydrochlorothiazide (HCTZ) and aliskiren (ALI) in pharmaceutical formulations. The HPLC method was carried out on a monolithic C18 column (100 mm × 4.6 mm id), maintained at 45°C. The mobile-phase consisted of acetonitrile-sodium phosphate (pH 4.0; 30 mM) (33:67, v/v), run at a flow rate of 2.4 mL/min, using photodiode array detection at 208 nm. Validation parameters such as the specificity, linearity, precision, accuracy, and robustness were evaluated according to the ICH guidelines. The method was linear in the range of 5–200 µg/mL (r2 > 0.9992) for both drugs. The specificity and stability indicating capability of the method were demonstrated through degradation studies, which also showed that there was no interference from the excipients. Plackett-Burman experimental design and a 23 full factorial design were employed to estimate the robustness and intermediate precision, respectively. The chromatographic separation was obtained within 2 min and it was suitable for high-throughput analysis. The proposed HPLC method was successfully applied for the simultaneous quantitative analysis of HCTZ and ALI in tablet dosage forms, contributing to improve the quality control and to assure the therapeutic efficacy.