Metal nanoparticle (MNP)-catalyzed synthesis of nitrogen- and oxygen-containing heterocyclic scaffolds.

A robust and eco-friendly stability-indicating high-performance thin-layer chromatography (HPTLC) method was developed for the stability study of thiocolchicoside using analytical quality-by-design approach. Full factorial design was used for screening potential variables affecting method development. Box‒Behnken design was used subsequently for investigation of the main, interactive, and quadratic effects of these variables on response. Four potential variables were selected on the basis of scientific knowledge for the development of a method for the stability study of thiocolchicoside. The selected potential factors, namely, volume of water (mL), saturation time (min), migration distance (mm), and volume of mobile phase (mL) were screened by 24 full factorial designs by selecting resolution as a critical method attribute. Pareto chart analysis showed that 3 variables, namely, volume of water (mL), saturation time (mm), and migration distance (mm), out of 4 potential variables were significantly affectin...

Nitrosamine impurities are potent carcinogens in animals and probable carcinogens in humans. In current scenario, there is a need for effective analytical methods to detect and identify various nitrosamine impurities, and to develop rapid solutions to ensure the safety and quality of the drugs. In present work, liquid chromatographic method was developed for estimation of six nitrosamine impurities in Valsartan. The developed method employed C₁₈ (250 × 4.6 mm, 5 μ) column as a stationary phase, combination of acetonitrile, water (pH 3.2 adjusted with formic acid) and methanol with gradient elution as mobile phase and 228 nm as detection wavelength. Developed method was validated as per ICH Q2(R1) guideline. Method was successfully applied to estimate six nitrosamine impurities in Valsartan API and formulation (tablets). Method was able to separate each impurity and Valsartan with resolved and sharp peaks. Results indicated that developed method is linear in selected ranges (coefficient of regressions > 0.9996), precise (RSD < 2%), accurate (recovery in a range of 99.02–100.16%), sensitive (low detection and quantitation limits) and specific for estimation of each impurity in Valsartan. Assay results were found in agreement with the amount of each impurity spiked. Developed method can be applied for simultaneous estimation of six nitrosamine impurities in Valsartan raw material, tablets and fixed dose combination at very low level. Development, validation and application of HPLC method for estimation of six nitrosamine impurities in Valsartan API and formulation samples.

A rapid, sensitive, and stability-indicating high-performance thin-layer chromatographic method was developed and validated to study degradation kinetics of Alogliptin benzoate (ALG) in an alkaline medium. ALG was degraded under acidic, alkaline, oxidative, and thermal stress conditions. The degraded samples were chromatographed on silica gel 60F254-TLC plates, developed using a quaternary-solvent system (chloroform–methanol–ethyl acetate–triethyl amine, 9+1+1+0.5, v/v/v/v), and scanned at 278 nm. The developed method was validated per International Conference on Harmonization guidelines using validation parameters such as specificity, linearity and range, precision, accuracy, LOD, and LOQ. The linearity range for ALG was 100–500 ng/band (correlation coefficient = 0.9997) with an average recovery of 99.47%. The LOD and LOQ for ALG were 9.8 and 32.7 ng/band, respectively. The developed method was successfully applied for the quantitative estimation of ALG in its synthetic mixture with common excipients. Degradation kinetics of ALG in an alkaline medium was studied by degrading it under three different temperatures and three different concentrations of alkali. Degradation of ALG in the alkaline medium was found to follow first-order kinetics. Contour plots have been generated to predict degradation rate constant, half-life, and shelf life of ALG in various combinations of temperature and concentration of alkali using Design Expert software.