Simultaneous Uplc Assay for Oxitropium Bromide and Formoterol Fumarate Dihydrate in Pressurised Metered Dose Inhaler Products for Chronic Obstructive Pulmonary Disease

Backround Oxitropium Bromide (OB) and Formoterol Fumarate Dihydrate (FFD) are inhaler molecules that are widely used in the treatment of chronic lung diseases. Objective The goal of this work was to create a reversed phase-ultra performance liquid chromatography (RP-UPLC) technique for assay and identification of OB and FFD, as well as identification and estimate of its associated compounds in pressurised metered dose inhaler product (pMDI). Method Separation of oxitropium and formoterol peaks were enhanced on C18 (50 x 2.1 mm x 1.7 μm), UPLC column with Ethylene-Bridged-Hybrid technology, The mobile phase consists of buffer (0.07 M KH2PO4) and acetonitrile (80:20 v/v). The detector wavelength of 210 nm, flow rate of pump 0.6 mL/min and oven temperature for column were set at 25◦C. The injection volume was 10 μL. The method run time is 2 min. The mobile phase was used as the solvent. Results Retention times were 0.5 min. for OB and 1.0 min. for FFD. The assay analysis was lineear range for all analytes within the range for concentrations 0.03—14.8 µg/mL of OB, 0.01– 0.88 µg/mL of FFD. LOD values and LOQ values 0.009 µg/mL and 0.026 µg/mL for OB, 0.003 µg/mL and 0.009 µg/mL for FFD, respectively. Recoveries were obtained at 96.3% for OB and 97.2% for FFD. Precisions values were (as RSD%) ≤1.5%. Conclusions With the UPLC method developed and validated according to the current ICH guidelines, it is possible to simultaneously detect OB and FFD of assay analysis in pMDI products accurately, precisely and selectively, independent of the matrix effect. Highlights The present method is the first method in the literature based on the UPLC method for this purpose. The UPLC method is a time-saving method, it provides a faster and cheaper technique than the HPLC method.