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Abstract This study presents a stability indicating high-performance liquid chromatography HPLC method for the determination of cenobamate (CNB) in presence of its main impurity (CNB H-impurity) and degradation products. The chromatographic separation was carried out on a Thermo BDS Hypersil-C18 column (150 × 4.6 mm; 5 μm) with a mobile phase consisting of a 50:50 (%v/v) ratio of methanol and purified water. The flow rate was maintained at 1.0 mL. min− 1. CNB was detected at 210 nm using a PDA detector. The column temperature was held at 40 °C.The retention time of the drug was found to be 3.2 min. Furthermore, the study investigates the degradation behavior of CNB under various stress conditions, including acidic, basic, oxidative, and light-induced degradation. The results indicate that CNB is particularly susceptible to basic degradation. Consequently, a comprehensive study of the basic degradation kinetics was conducted. The method was also successfully applied for the determination of CNB in its dosage form. The results also show that there is no co-elution from degradation products or excipients as indicated by the mass balance and peak purity values confirming the specificity of the proposed method and its applicability for routine analysis of CNB.

Abstract This study presents two spectrophotometric methods; a novel dual wavelength—derivative spectrophotometry and multivariate curve resolution-alternating least squares (MCR-ALS) for the simultaneous determination of a fixed dose combination of bupivacaine (BUP) and meloxicam (MEL) in a ratio of 30:1. The extended UV spectrum of MEL enables its direct determination at λmax 360 nm with no interference from BUP. The determination of BUP was unfeasible directly because the UV spectra of both drugs are moderately overlapped over the wavelength range of 250–450 nm, thus new chemometric based spectrophotometric methods should be developed for its determination. Dual wavelength-derivative method was employed based on using first derivative spectra. The selected dual wavelengths for determination BUP were 274.6 nm and 374.6 nm where the dA/dλ amplitudes differences for MET are equal to zero. MCR-ALS is advanced chemometric tool that enables analysis of multicomponent samples in complex matrices with high resolution based on the decomposition of signal/spectral data into the pure spectra and corresponding concentration profile. The figures of merits for MCR model show that there is a good agreement between the actual and predicted concentrations for MEL and BUP. The methods were validated and statistically compared with a reported HPLC method.

Abstract Recently, significant attention has been directed towards digital image colorimetry DIC using mobile applications or available software programs, which offer the advantage of analyzing samples without the need for sophisticated instruments. One such image processing program is Image J, widely used for obtaining quantitative information from scientific images. Image J could measure the color intensities by quantifying of the RGB (red–green–blue) gray levels across the images of colored substances. These values are correlated to the color intensities through conversion to CMY (cyan–magenta–yellow) values which are proportional to the color intensities. The objective of this study is to develop an innovative analytical method for the quantitative determination of uric acid using Image J for color quantification. Image J was utilized to analyze images captured by smart phone for successive concentrations of uric acid that were previously treated with phosphotungstate to develop a blue color. The proposed method has been applied for determination of uric acid in real urine using standard addition method and the results were compared with UV/VIS spectrophotometry as a reference method. In this research, we will also assess the effectiveness of quantitative analysis using Image J in comparison to a mobile application, namely RGB Color Detector.