A novel approach for nanoemulsion components screening and nanoemulsion assay of olmesartan medoxomil through a developed and validated HPLC method

Abstract

A novel sensitive, specific, reproducible and innovative reverse-phase high-performance liquid chromatographic method was developed for the detection of olmesartan medoxomil. A Hypersil BDS C₁₈, 250 × 4.6 mm, 5 μm particle size column with a mobile phase composed of acetonitrile and 10 mM KH₂PO₄ buffer (pH 3.5) in a ratio of 55 : 45 v/v was used at a flow rate of 1.0 mL min⁻¹ and the effluents were monitored at 250 nm. The calibration curve was linear in the range of 5.0 to 150.0 μg mL⁻¹ with a determination coefficient (r²) of 0.998 that had been calculated by a least-squares regression method. The method is simple and rapid with a run time of 8.0 min. The method was fully validated according to ICH guidelines. This sensitive method with a LOD of 10.0 ng mL⁻¹ and LOQ of 30.0 ng mL⁻¹ showed precision in the range of 0.58–0.97% with an accuracy ranging between 98.84 and 101.53% and is selective for nanoemulsion assay and solubility determination in different matrices (oils, surfactants and mixtures of both). This method was successfully applied to quantitatively assess the solubility of olmesartan medoxomil in various oils, surfactants and mixtures of both. The innovative application of this method was the assay of olmesartan medoxomil, for the first time, in novel formulations such as in a nanoemulsion. Thus it acts as a guideline for preliminary screening studies for novel nanoemulsion formulations apart from just being a HPLC method.