Spectrophotometric Approaches for Concurrent Estimation of Formoterol Fumarate Dihydrate and Fluticasone Propionate in their Binary Inhaler Combination.

Formoterol fumarate dihydrate (FFD) is a long-acting β2 agonist, while Fluticasone propionate (FP) is a synthetic glucocorticoid receptor agonist. Both are used to manage chronic asthma and chronic obstructive pulmonary disease. The objective of this work is the quantitative analysis of the two drugs concurrently in their pure raw powder and medication dosage form, synthetic laboratory mixtures by three simple, precise, sensitive, and accurate spectrophotometric techniques operating on ratio spectra with the advantages of low-cost, high sensitivity, and no previous separation. Method (I) is based on the ratio subtraction method, which allows FP to be determined without the interference of FFD at its λmax of 236 nm. Method (II) is the first derivative of the ratio spectra, which enabled the measurement of peak amplitude of D1 spectra at 233.2 nm for FP and 301.0 nm for FFD. Method (III) is the ratio difference spectrophotometry, where the difference in values between (214.4 and 236.0 nm) was calculated for the determination of FP; and the difference of peak amplitudes at 270.0 and 290.0 nm for the estimation of FFD. The linearity of the calibration curve considered the range of concentrations of 2.0–12.0 and 2.5–25.0 µg/mL for FFD and FP, respectively. The accuracy and precision of the three achieved methods have been assayed to verify their validation according to ICH guidelines. They were 100.1 ± 1.3, 101.5 ± 0.5, and 101.2 ± 1.2 for FP, and 99.2 ± 1.6 and 100 ± 2 related to FFD. Regarding precision, the relative standard deviation was not more than 1.5%. The specificity of the three methods was estimated through their determination in various synthetic laboratory mixes. Additionally, the obtained results by the suggested procedures are compared statistically to those obtained by the reported HPLC technique. Another statistical comparison was done using a one-way ANOVA test; all of them showed no discernible differences. The three methods are specific, simple, and do not require sophisticated instruments. They can be employed in quality control laboratories for routine assays of two drugs in pure raw powder, synthetic laboratory-prepared mixes, and medication dosage forms quantitatively, and have been successfully utilized and validated. [ABSTRACT FROM AUTHOR]