Background Over the few previous years, mathematical manipulation proved to be a very powerful practice for successfully resolving severely overlapped spectra for various multicomponent mixtures. Objective Smart and environmentally friendly spectrophotometric determination approaches were conducted for two binary mixtures; of fixed dose veterinary injections containing Flunixin meglumine (FLU); combined with either Florfenicol (FLR), or Oxytetracycline HCl (OXY). Methods Regarding the first mixture, both FLU and FLR were determined by three successive resolution techniques which were; constant multiplication coupled with spectrum subtraction (CM-SS), derivative ratio (DD1),and ratio difference (RD),and two progressive resolution techniques which were absorbance subtraction (AS) and amplitude modulation (AM). In addition to graphical representation of concentration of the two drugs through concentration value (CNV) method. Concerning the second mixture, both FLU and OXY showed severely overlapped spectra and a comparative study was conducted for the determination of each drug by constant center (CC), ratio subtraction via amplitude difference coupled with spectrum subtraction (RS/AD-SS), constant value via amplitude difference (CV-AD), and advanced concentration value (ACV) method Results Calibration graphs of the first mixture were linear over the range of 5–40 µg/mL for FLU, and 3–40 µg/mL for FLR. The proposed methods overcame the problem of the overlapped spectra and presence of a minor component in mixture. Regarding the second mixture, calibration graphs were linear over the range of 2.5–24 µg/mL for FLU and 4–28 µg/mL for OXY. Conclusion The proposed methods were succesfully validated as per ICH guidelines. The obtained results were statistically compared with the official or reported methods showing no significant difference concerning accuracy and precision. The methods were evaluated for greenness by three different assessment tools; NEMI, analytical ecoscale, and GAPI. Highlights The methods were successfully applied for the simultaneous determination of the two combinations in synthetic mixtures and their marketed antibiotic veterinary injections; Megluflor® and Floxon®.

This work describes a comparative study of two multivariate chemometric and univariate spectrophotometric methods for the determination of a ternary drug mixture containing oxytetracycline HCl, bromhexine HCl, and lidocaine HCl. All methods show high sensitivity and similar linearity range. Meanwhile, the chemometric method has the advantage of higher accuracy, higher specificity and better regression parameters. The two spectrophotometric methods are constant multiplication coupled with spectrum subtraction and successive ratio subtraction coupled with spectrum subtraction while the chemometric method used partial least square and principal component regression models. In addition, a spiking technique was used to increase the concentration of bromhexine HCl in the dosage form, allowing its determination despite its low contribution. Methods were successfully applied in the dosage form Oxyclear® veterinary injection in pure powder as well as in its pharmaceutical formulation. Statistical comparison showed no significant difference between the developed methods and the reference method.