RESUMEN
Simple, direct, rapid, and sensitive HPLC and spectrophotometric methods were established for simultaneous estimation of a novel combination of budesonide and azelastine (BUD/AZL) in their laboratory-prepared mixture and dosage form according to the medicinally recommended ratio 1:4.28. Budesonide is an important inhalation corticosteroid that plays a vital role in the inhibition of COVID-19 replication and cytokine production. The first chromatographic method was created for the simultaneous estimation of BUD epimers in the presence of AZL with excellent efficiency in a relatively short chromatographic run (< 9 min). The separation of BUD epimers with AZL was carried out on a C18 column using acetonitrile: phosphate buffer of pH 3.5 adjusted by 0.2 M orthophosphoric acid (40:60, v/v) as a mobile phase, UV detection at 230 nm and a flow rate of regulated at 2 mL/min. Besides, three spectrophotometric methods were applied for the simultaneous determination of the provided mixture adopting zero order, first order derivative, and ratio first derivative approaches. The Zero-order spectrophotometry was used for the determination of AZL in presence of BUD, where BUD shows no absorbance at 290 nm. The first derivative amplitude at 265 nm (1D265) (zero-crossing of AZL) and the ratio of first derivative amplitudes at 270 nm (1DD270) using 10.0 µg mL-1 AZL as divisor was chosen for the simultaneous determination of BUD in the presence of AZL in the binary mixture. The proposed methods were found to be rectilinear in the concentration range of (0.4-40.0 µg mL-1) and (0.05-40.0 µg mL-1) for BUD and AZL, respectively in the HPLC method. Whereas the concentration range for AZL in the zero-order method was (1.0-35.0 µg mL-1) and for BUD in the first derivative and ratio derivative method was (6.0-20.0 µg mL-1). Validation of the suggested approaches according to the ICH criteria was performed. Furthermore, to ensure the proposed approaches' greenness, The AGREE and GAPI metrics were utilized, and the afforded results revealed an excellent greenness of the proposed approaches.
RESUMEN
Simple, fast, and precise reversed-phase (RP)-high-performance liquid chromatography (HPLC) and two ecofriendly spectrophotometric methods were established and validated for the simultaneous determination of moxifloxacin HCl (MOX) and flavoxate HCl (FLX) in formulations. Chromatographic methods involve the separation of two analytes using an Agilent Zorbax SB C18 HPLC column (150 mm × 4.6 mm; 5 µm) and a mobile phase consisting of phosphate buffer (50 mM; pH 5): methanol: acetonitrile in a proportion of 50:20:30 v/v, respectively. Valsartan was used as an internal standard. Analytes were monitored by measuring the absorbance of elute at 299 nm for MOX and 250 nm for FLX and valsartan. Two environmentally friendly spectrophotometric (first derivative and ratio first derivative) methods were also developed using water as a solvent. For the derivative spectrophotometric determination of MOX and FLX, a zero-crossing technique was adopted. The wavelengths selected for MOX and FLX were -304.0 nm and -331.8 nm for the first derivative spectrophotometric method and 358.4 nm and -334.1 nm for the ratio first-derivative spectrophotometric method, respectively. All methods were successfully validated, as per the International Conference on Harmonization(ICH) guidelines, and all parameters were well within acceptable ranges. The proposed analytical methods were successfully utilized for the simultaneous estimation of MOX and FLX in formulations.