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A new green micellar liquid chromatographic method has been developed and validated for the simultaneous determination of diphenhydramine (DPH) and tripelennamine hydrochloride (TRP) using a micellar mobile phase consisting of 1 mM Tween 20 in phosphate buffer pH 4:isopropanol (85:15, %v/v). The method was linear in the range of 4–150 and 5–120 μg/mL for TRP and DPH, respectively. The method was successfully applied for the simultaneous determination of DPH and TRP in a laboratory‐prepared gel containing all possible excipients with mean percent recoveries ± standard deviation of 100.346 ± 1.265 and 100.754 ± 1.117 for TRP and DPH, respectively. The method was validated according to the International Conference on Harmonization guidelines. The method is confirmed to have excellent greenness. [ABSTRACT FROM AUTHOR]

Background: Ascorbic acid (ASC; vitamin C) is a weak chromophore, so its presence cannot be determined directly by spectrophotometry. Objective: This work aims to develop and validate a simple and ecofriendly analytical method for the determination of ASC concentration based on the reaction of ASC with the metal complex, ferric salicylate. Methods: The visible absorbance of ferric salicylate was found to be inversely proportional to the concentration of ASC. The possible mechanism of the reaction between ASC and ferric salicylate was investigated: ferric salicylate was found to be reduced by ASC under the applied experimental conditions. Different parameters that may affect the reaction were also investigated: ferric salicylate concentration, pH, ionic strength, and the time of reaction. The optimum concentration of ferric salicylate was found to be 1000 mM and the optimum pH was 5.5. The developed method was validated according to International Conference on Harmonization (ICH) guidelines. Results: The linearity range of the developed method was 5-70 mg/mL and the correlation coefficient was 0.9994. The limits of detection and quantitation were 0.38 mg/mL and 1.16 mg/mL, respectively. The method was successfully applied to the determination of ASC concentration in commercial Ruta-C60VR tablets. The mean recovery 6 standard deviation was found to be 101.1060.70%. The results were statistically compared to those obtained by a reported HPLC method. Good agreement was observed. Conclusion: The developed method is simple, fast, cost-effective, and suitable for routine pharmaceutical analysis of ASC. Highlights: The developed method is more sensitive than the other spectrophotometric methods reported for determination of ASC. [ABSTRACT FROM AUTHOR]

Abstract: Highly sensitive, rapid, accurate and precise synchronous fluorescence spectrofluorimetric method has been developed for simultaneous analysis of a mixture of amlodipine (AMD) and metoprolol (MET). The method relies on measuring the relative synchronous fluorescence intensity of both drugs at Δλ of 90 nm in acetate buffer solution at pH 5. The experimental parameters influencing the developed method were investigated and optimized. The method was linear over the ranges 0.2–2 μg/ml and 0.5–10 μg/ml for AMD and MET, respectively. The limits of detection were 50 ng/ml for AMD and 130 ng/ml for MET while the limits of quantitation were 150 ng/ml for AMD and 390 ng/ml for MET. The developed method was applied successfully for the determination of the two drugs in their co‐formulated tablet. The mean percent recoveries were found to be 100.51 and 99.57 for AMD and MET, respectively. [ABSTRACT FROM AUTHOR]

Highly sensitive, rapid, accurate and precise synchronous fluorescence spectrofluorimetric method has been developed for simultaneous analysis of a mixture of amlodipine (AMD) and metoprolol (MET). The method relies on measuring the relative synchronous fluorescence intensity of both drugs at Δλ of 90 nm in acetate buffer solution at pH 5. The experimental parameters influencing the developed method were investigated and optimized. The method was linear over the ranges 0.2-2 μg/ml and 0.5-10 μg/ml for AMD and MET, respectively. The limits of detection were 50 ng/ml for AMD and 130 ng/ml for MET while the limits of quantitation were 150 ng/ml for AMD and 390 ng/ml for MET. The developed method was applied successfully for the determination of the two drugs in their co-formulated tablet. The mean percent recoveries were found to be 100.51 and 99.57 for AMD and MET, respectively., (Copyright © 2017 John Wiley & Sons, Ltd.)