Validated rp-hplc method development for the simultaneous estimation of glycopyrrolate and formoterol in its combined dosage forms

Abstract

A new, simple, precise, accurate and reproducible RP-HPLC method for Simultaneous estimation of Glycopyrrolate and Formoterol in bulk and pharmaceutical formulations. Separation of Glycopyrrolate and Formoterol was successfully achieved on a Phenomenex Luna C18 (4.6×250mm, 5µm) particle size or equivalent in an isocratic mode utilizing Acetonitrile: Phosphate Buffer (pH-4.6) (45:55 v/v) at a flow rate of 1.0mL/min and eluates was monitored at 245nm, with a retention time of 2.102 and 3.537 minutes for Glycopyrrolate and Formoterol respectively. The method was validated and the response was found to be linear in the drug concentration range of 10µg/mL to 50µg/mL for Glycopyrrolate and 20µg/mL to 100µg/mL for Formoterol. The values of the slope and the correlation coefficient were found to be 77824 and 0.999 for Glycopyrrolate and 10515 and 0.999 for Formoterol respectively. The LOD and LOQ for Glycopyrrolate were found to be 0.6µg/mL and 1.8µg/mL respectively. The LOD and LOQ for Formoterol were found to be 0.8 µg/mL and 2.4µg/mL respectively. This method was found to be good percentage recovery for Glycopyrrolate and Formoterol were found to be 100.351 and 100.93 respectively indicates that the proposed method is highly accurate. The specificity of the method shows good correlation between retention times of standard with the sample so, the method specifically determines the analytes in the sample without interference from excipients of tablet dosage forms. The method was extensively validated according to ICH guidelines for Linearity, Range, Accuracy, Precision, Specificity and Robustness.