Spectrophotometric Methods for Simultaneous Determination of Oxytetracycline HCl and Flunixin Meglumine in Their Veterinary Pharmaceutical Formulation

Abstract

Four precise, accurate, selective, and sensitive UV-spectrophotometric methods were developed and validated for the simultaneous determination of a binary mixture of Oxytetracycline HCl (OXY) and Flunixin Meglumine (FLU). The first method, dual wavelength (DW), depends on measuring the difference in absorbance (ΔA 273.4–327 nm) for the determination of OXY where FLU is zero while FLU is determined at ΔA 251.7–275.7 nm. The second method, first-derivative spectrophotometric method (1D), depends on measuring the peak amplitude of the first derivative selectively at 377 and 266.7 nm for the determination of OXY and FLU, respectively. The third method, ratio difference method, depends on the difference in amplitudes of the ratio spectra at ΔP 286.5–324.8 nm and ΔP 249.6–286.3 nm for the determination of OXY and FLU, respectively. The fourth method, first derivative of ratio spectra method (1DD), depends on measuring the amplitude peak to peak of the first derivative of ratio spectra at 296.7 to 369 nm and 259.1 to 304.7 nm for the determination of OXY and FLU, respectively. Different factors affecting the applied spectrophotometric methods were studied. The proposed methods were validated according to ICH guidelines. Satisfactory results were obtained for determination of both drugs in laboratory prepared mixture and pharmaceutical dosage form. The developed methods are compared favourably with the official ones.

Green validated chromatographic methods for simultaneous determination of co-formulated oxytetracycline HCl and flunixin meglumine in the presence of their impurities in different matrices

“…The presented chromatographic methods were more straightforward and rapid than spectrophotometric ones because of a direct separation of the binary mixture with fewer mathematical steps. Moreover, the proposed chromatographic methods are more advantageous than the three reported spectrophotometric and chromatographic methods in their higher sensitivity of 0.05 µg/mL rather than the spectrophotometric one which was 5 µg/mL [31], while in the other spectrophotometric methods were 2.5 and 4 µg/ mL for FLU and OXY, respectively [32] and also mentioned to be 32 and 160 µg/mL for FLU and OXY, respectively in the reported chromatographic method [33] that allow the application of the suggested methods for minor traces determination in biological matrices. Furthermore, the proposed methods were more selective than published ones owing to awarding simultaneous separation of both drugs and their impurities in active pharmaceutical ingredients (API).…”

“…According to our knowledge, two spectrophotometric and one chromatographic methods were reported for simultaneous determination of OXY and FLU in their pharmaceutical preparation [31][32][33]. The presented chromatographic methods were more straightforward and rapid than spectrophotometric ones because of a direct separation of the binary mixture with fewer mathematical steps.…”

“…These include spectrophotometric [8,9], TLC densitometric [9] HPLC [10][11][12][13], colorimetric [14,15], fluorometric [16,17], and electrochemical methods [18], while FLU was determined by spectrophotometric [19], HPLC [20][21][22][23][24][25][26][27], voltammetric [28,29], and fluorometric methods [30]. Two spectrophotometric methods [31,32] and one chromatographic method 1 3 [33] were reported for the simultaneous determination of OXY and FLU in their pharmaceutical preparation.…”

“…Three methods [31][32][33] were reported for the simultaneous determination of OXY and FLU in their pharmaceutical preparation. But these methods lack the identification of impurities in active pharmaceutical ingredients (API) which is one of the most highly regarded topics.…”

New spectral resolution techniques for resolving and determining the components in binary fixed-dose combinations

“…Various approaches were announced for PHN determination like spectrophotometry [2, 3, 4, 5] HPLC [6, 7, 8], TLC [9], GC [10, 11] and capillary zone electrophoresis methods [12], whereas BEN was determined by spectrophotometry [13, 14, 15, 16, 17, 18], HPLC methods [19, 20, 21, 22, 23, 24]. Simultaneous quantification of PHN and BEN existing in otic drop formulation was announced in previous published studies by spectrophotometric [25, 26], HPLC [27, 28] and TLC [29] methods.

Fig. 1Structural formulae of (a) Phenazone and (b) Benzocaine.

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