Pharmacokinetics and bioequivalence study of candesartan cilexetil tablet in Chinese volunteers under fasting condition: an open-label, randomized-sequence, 2-period crossover study.

Candesartan is an antihypertensive agent that acts on an angiotensin II receptor. Candesartan cilexetil is a prodrug that is converted into the active form of candesartan during intestinal absorption. This study aimed to assess the pharmacokinetics and bioequivalence of a reference and a test formulation of candesartan cilexetil tablets in healthy Chinese volunteers. A randomized, open-label, single-dose, crossover study was conducted with two treatment periods. Forty-eight healthy Chinese volunteers participated under fasted conditions. Qualified subjects were randomly divided into two groups (1:1 ratio) to receive either the test or reference formulation first. A washout period of 14 days separated the administration of the two formulations. Blood samples were collected at specific time points and analyzed for candesartan concentration using Ultra High-Performance Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS/MS). The maximum concentration (Cmax), the AUC from time zero to the last measured time point (AUC0-t) and the AUC from time zero to infinity (AUC0-∞) fell within the bioequivalence range of 80% to 125%. These results suggest that the test and reference formulations of candesartan cilexetil tablets are bioequivalent, meaning they have similar rates and extents of absorption in healthy Chinese volunteers. No serious adverse events or side effects were reported throughout the study.

Separation of Three Phenanthrenes and Two Bibenzyls from Chloroform Fractions of Pholidota Articulata Lindl. Using HPLC.

BACKGROUND: Pholidota articulata Lindl has been used as a traditional medicine and Yi-nationality herbal medicine for the treatment of various diseases. Phenanthrenes and bibenzyls commonly found in the genus Pholidota are one of their most important natural ingredients, due to their various biological activities. OBJECTIVE: This study aimed to establish an HPLC method for determination of the levels of three phenenthrenes (flavidin, lusianthridin, coelonin) and two bibenzyls (batatasin III, cirrhopetalidin) in rhizomes of P. articulata Lindl. METHOD: The separated and elucidated compounds from chloroform fractions of P. articulata Lindl were used as standards and analyzed by gradient elution HPLC with a variable wavelength detector at 274 nm. RESULTS: The calibration curves exhibited good linearity (R2 = 0.9999), ranging from 20 to 960 ng/mL, the average recoveries were between 91.5 and 102.9%, and the RSD values of precision, stability, and repeatability were <2.34%. There were significant differences in the content of phenenthrenes and bibenzyls from the plants of genus Pholidota, Dendrobium, and Bulbophyllum. Furthermore, this is the first report on the validation of a method for the quantitative analysis of flavidin and cirrhopetalidin. CONCLUSIONS: The present study provides an alternative method for the rapid separation of phenanthrenes and bibenzyls from natural products and lays a foundation for the study of biological activity. HIGHLIGHTS: When using developed method in this study for separation of phenanthrenes and bibenzyls in genus Pholidota, chemicalin formation was more abundant from chloroform fractions.