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Background: The liver perfusion method is frequently used in drug pharmacokinetic studies and the various effects of drugs on liver tissue. The aim of this study was to establish and validate an analytical method using high-performance liquid chromatography to determine the simultaneous concentration of losartan and its active metabolite, EXP-3174, in an isolated perfused rat liver study.Method: An HPLC system with isocratic mode was used. Various chromatographic parameters were adjusted to develop and validate a method for determination of losartan and its active metabolite in liver perfusion media.Results: In this study, losartan and its active metabolite, EXP-3174, were separated using a C18 stationary phase, a mobile phase consisting of acetonitrile: phosphate buffer at a flow rate of 1 mL.min-1, and UV detection at 254 nm. Retention times for losartan and the metabolite were 10 and 16 minutes, respectively. Linearity from 25-250 ng.ml-1 was validated with acceptable accuracy and precision. The LOD and LOQ for losartan were 7.0 and 21.1 ng.ml-1, respectively. The LOD and LOQ for metabolite were 7.4 and 22.4 ng.ml-1, respectively. ChromGate® software was used to acquire and process the data.Conclusions: The optimized and validated technique was effectively used to analyze losartan and its active metabolite in isolated perfused rat liver.

Background: Sample preparation is one of the most challenging phases in pharmaceutical analysis, especially in biological matrices, affecting the whole analytical methodology. Objective: In this study, a new Ca(II)/Cu(II)/alginate/CuO Nanoparticles Hydrogel Fiber (CCACHF) was synthesized through a simple, green procedure and applied for fiber micro solid-phase extraction (FMSPE) of diazepam (DIZ) and oxazepam (OXZ) as model drugs prior to high-performance liquid chromatography-UV detection (HPLC-UV). Methods: Composition and morphology of the prepared fiber were characterized and the effect of main parameters on the fiber fabrication and extraction efficiency have been studied and optimized. Results: In optimal conditions, calibration curves were linear, ranging between 0.1–500 μg L−1 with regression coefficients of 0.9938 and 0.9968. Limit of Detection (LOD) (S/N=3) and Limit of Quantification (LOQ) (S/N=10) of the technique for DIZ and OXZ were 0.03 to 0.1 μg L−1. Within-day and between-day Relative Standard Deviations (RSDs) for DIZ and OXZ were 6.0–12.5% and 3.3–9.4%, respectively. Conclusion: The fabricated adsorbent has been substantially employed to the extraction of selected benzo-diazepines (BZDs) from human serum real specimens and the obtained recoveries were also satisfactory (82.1-109.7%).

Extraction of bisphosphonates from biological fluids is important and time consuming step in sample preparation procedure. This paper describes a simple and green sample preparation technique for dispersive micro solid phase extraction (DMSPE) of alendronate sodium (ALS) from urine and serum samples prior to direct spectrofluorimetry (DSFL) and high performance liquid chromatography with fluorescence detection (HPLC-FLD), respectively. The DMSPE strategy is based on the selective chemisorption of ALS on zirconia nanoparticles (ZNPs) as an adsorbent followed by derivatization of the eluted analyte using o-phthalaldehyde (OPA) in the presence of 2-mercaptoethanol (2ME) at basic medium to form fluorescent species. The chemical and instrumental influencing parameters on DMSPE and measuring methods were optimized for the efficient extraction and determination of ALS. The presented methods were capable of extracting ALS from human urine and serum samples and determining over the wide ranges of 5–1000 and 5–2500 μg L−1with limits of detection (LOD) of 1.5 and 1.4 μg L−1for DSFL and HPLC methods, respectively. The relative recoveries for the three spiked standard levels of ALS in urine and serum samples ranged from 89.0% to 107.0%, and the intra-day relative standard deviations (%RSDs) were in the range of 2.9–7.9%.

Nano-CuO modified carbon paste electrode was successfully applied for square wave voltammetric determination of lidocaine.

Two important challenges in clinical application of 5-Fluorouracil (5-FU) in the treatment of colon cancer are preventing the release or degradation of the drug in the stomach/small intestine, and its delivering the colon as the site of action. The preparation of targeted liposomes using a suitable ligand and their encapsulation may be a promising method for the targeted treatment of colon cancer. The targeted liposomes were prepared by the optimized thin film method, and anti-nucleolin aptamer (AS1411) was used as the ligand. The nanocapsules were then prepared by coating of the synthesized liposomes with alginate and chitosan solution. The chemical structure, particle size and morphology of the liposomes and the nanocapsules were examined by Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), zeta potentiometer and field emission scanning electron microscopy (FESEM). MTT cytotoxicity studies were performed in vitroon the colon cancer cell line (HT-29). The liposomes and nanocapsules prepared were spherical with approximate sizes of 120 and 170 nm, respectively. The cytotoxicity studies on HT-29 cells showed that aptamer-conjugated liposomes induced significantly more cell death than aptamer-free liposomes and free drug. The results of the drug release experiments under simulated conditions including stomach, small intestine, and colon showed the excellent efficiency of the nanocapsules in releasing their cargo only under colonic condition.