Nio nanoflower based sorbent extraction for a novel HPLC–UV method for the determination of solifenacin in human plasma and its application to a prototype pharmacokinetic study

Solifenacin is an active pharmaceutical product used in overactive therapy. The main goal of this work was to develop a high-performance liquid chromatographic (HPLC) method with ultraviolet detection for measuring the amount of quanti fied solifenacin in human plasma samples that is rapid, straightforward, and accurate. Prior to chromatographic analysis, a nanomaterial-based sorbent extraction technique utilizing NiO nanoflowers was employed for plasma sample preparation. In this method, NiO nanoflowers were employed, and the adsorption process underwent optimization. Chromatographic separation was carried out using a reversed-phase C18 analytical column (5 µm×4.6 mm×150 mm) with a mobile phase composed of water (0.2% triethylamine) and acetonitrile (30:70 v/v), and the pH was adjusted to 3.5 with ortho-phosphoric acid. The flow rate was set at 1.0 mL/min, and the investigation was performed using UV at 220 nm. The retention time of solifenacin is 3.10±0.01 min. The linear behaviour of the proposed approach was examined in the 0.01–30 ng/mL range (r 2=0.9995). The proposed method is in alignment with the criteria established by the European Medical Agency (EMA) about the accuracy, precision, repeatability, specificity, robustness and detection and quantification. Limit of detection and limit of quantification are determined to be 0.003 and 0.01 ng/mL, whereas relative standard deviation was determined to be less than 2.75% for intra-run and inter-run measurements. The plasma concentration–time profile and pharmacokinetic parameters such as AUC0–t , AUC0–∞, Cmax, tmax, and t1/2, were calculated according to the assays. The proposed method is feasible to investigate the bioequivalence, bioavailability, and routine analysis of the drug in plasma.