RP-HPLC Method for Simultaneous Estimation of Formoterol Fumarate, Tiotropium Bromide and Ciclesonide in Pharmaceutical Metered Dose Inhalers

An accurate, sensitive, precise, rapid and isocratic Reversed-Phase HPLC, (RP-HPLC) method for simultaneous estimation of Formoterol Fumarate, Tiotropium Bromide and Ciclesonide in the bulk drug and in Pharmaceutical metered dose inhalers has been developed and validated. The best separation was achieved on a 250 mm × 4.6 mm i.d., 5-m particle, Inertsil ODS 3V-RP C18 column with Acetonitrile as the organic modifier and Di-Potassium Hydrogen Phosphate [0.03M] in water with pH 3.2 adjusted with Ortho-Phosphoric Acid (0.1% v/v) in the proportion of [30:70 v/v] as mobile phase at a flow rate of 0.8 mL min⁻¹. UV detection was at 254 nm. Retention times were found to be 5.206 min. for Formoterol Fumarate, 7.016 min. for Tiotropium Bromide and 9.991 min for Ciclesonide. The response was a linear function of concentration over the range of 0.72-8.64 mcg/ml, 1.08-12.96 mcg/ml and 24- 288 mcg/ml respectively with correlation coefficient of 0.9999. The percentage assay Formoterol Fumarate, Tiotropium bromide and Ciclesonide were found to be 98.87 %, 99.42 % and 98.91 % respectively. The Limit of Detection (LOD) for Formoterol Fumarate, Tiotropium bromide and Ciclesonide were found to be 1.44 µg/ml, 5.4µg/ml and 48µg/ml respectively. The Limit of Quantification (LOQ) for Formoterol Fumarate, Tiotropium bromide and Ciclesonide were found to be 4.32µg/ml, 16.2µg/ml and 144µg/ml respectively. The excipients present in the formulation were not interfered with the assay. The method is suitable for application in quality-control laboratories, because it is simple and rapid with good accuracy and precision.