Determination of assay and uniformity of content of ramipril and telmisartan in their multiple dosage forms by a developed and validated supercritical fluid chromatographic technique

Abstract

Considered a leading “green” separation technology, supercritical fluid chromatography (SFC) can be the best technique to separate and estimate chemical compounds. A precise, accurate and robust supercritical fluid chromatographic method was developed and validated for the determination of assay and uniformity of content of ramipril and telmisartan in their combined dosage forms. The chromatographic separation was achieved on a Zorbax SB-Phenyl column (150 mm × 4.6 mm, 5 μm) using supercritical carbon dioxide doped with 10% v/v methanol as a modifier, at a flow rate of 2.0 mL min⁻¹. Column oven temperature was 35.0 °C, and UV detection was performed at 205 nm. The densities and polarities of the mobile phase were optimized from the effects of pressure, temperature and modifier concentration on chromatographic parameters. The developed method was validated in terms of specificity, linearity and range, accuracy, robustness and precision applying International Conference on Harmonization guidelines. The method was successfully applied for the assay and for the uniformity of content of different marketed formulations containing ramipril and telmisartan individually and in combination.