trans-Resveratrol, a phytochemical compound with antioxidant power and various therapeutic effects, such as cardioprotective, chemopreventive, and neuroprotective, among others, has disadvantages of poor solubility and limited stability, creating difficulties for the development of new strategies for its quantification. This study developed and validated an analytical stability method for trans-resveratrol by high-pressure liquid chromatography with photodiode-array detection (HPLC-PDA), which allowed its quantification in the presence of its degradation products. The quantification of trans-resveratrol occurred at a retention time of 2.6min, with ammonium formate (10mM, pH=4)/acetonitrile, 70/30v/v, as mobile phase. The validation met the ICH Q2 criteria of specificity, method linearity (2.84.2μg/ml), precision and accuracy, robustness, quantification limit (0.176μg/ml), and detection (0.058μg/ml). As degradation products, cis-resveratrol was observed at 3.9min, which could be resveratrone in 3.2min and five unidentified products in 0.7, 1.0, 1.4, 1.8, and 5min. Some solutions subjected to temperature stress of 40 and 60°C, UV light, and acidic and basic hydrolysis exhibited colour changes. An analytical method was obtained by HPLC-PDA, which allowed quantifying the stability of trans-resveratrol in a fast and specific manner in the presence of its degradation products.

The use of the USP IV apparatus (flow-through cell) has gained acceptance in recent years due to its versatility and ability to discriminate due to its hydrodynamic conditions. Therefore, the objective of the present study was to develop a discriminative dissolution method in the USP IV apparatus using the open-loop configuration, as well as to propose a method to compare non-cumulative dissolution profiles obtained in the open-loop configuration considering kinetic parameters and validate its predictive power through its comparison with independent and dependent methods using five commercial immediate-release tablet drugs (one reference drug and four generic drugs) of metoprolol tartrate as a model drug. The comparison of the non-accumulated dissolution profiles consisted of determining the geometric ratio of C_max, AUC₀^∞, AUC₀^Cmax, and T_max (kinetic parameters) of the generic/reference drugs, whereby generic drugs “C” and “D” presented the highest probability of similarity since their 90% confidence intervals were included, or they were very close to the acceptance interval (80.00–125.00%). These results were consistent with the f₂, bootstrap f_2, and dissolution efficiency approaches (independent models). In conclusion, the proposed comparison method can be an important tool to establish similarity in dissolution profiles and to facilitate the development/selection of new formulations and positively ensure bioequivalence in clinical studies.

Curcumin (CUR) has shown promising anticancer activity against non-small cell lung cancer (NSCLC), but its poor biopharmaceutical properties limit its appl

A reversed phase high-performance liquid chromatography (RP-HPLC) method for determination of Thimerosal (TMS) in topical creams was optimized and validated according to the ICH guidelines which include accuracy, precision, selectivity, robustness, limit of detection (LOD), limit of quantification (LOQ), linearity and range. For topical creams, sample treatment is often an overwhelming step essentially due to its oily nature. For the first time a simple and robust extraction procedure for TMS using phosphate buffer (pH 5.5, 0.2M) was successfully developed. This method describes the TMS quantitation by HPLC in a topical product containing 0.01% fluocinolone acetonide (FLA) as the active molecule. The HPLC separation was achieved on a Column Symmetry® and a methanol: phosphate buffer (pH 2.5, 0.05M) 70:30 v/v mobile phase and wavelength 218 nm. Results from both standards and samples showed adequate validation parameters. Noteworthy, linearity was within the range 1.2 - 2.8 μg/mL. Additionally, robustness and TMS stability were established after sample extraction. The method provides an efficient and safe quality control tool for determination of TMS in topical creams.