Pharmacokinetic Comparison Between a Fixed-Dose Combination of Atorvastatin/Omega-3-Acid Ethyl Esters and the Corresponding Loose Combination in Healthy Korean Male Subjects.

Purpose: Statins are widely used in combination with omega-3 fatty acids for the treatment of patients with dyslipidemia. The aim of this study was to compare the pharmacokinetic (PK) profiles of atorvastatin and omega-3-acid ethyl esters between fixed-dose combination (FDC) and loose combination in healthy subjects. Methods: A randomized, open-label, single-dose, 2-sequence, 2-treatment, 4-period replicated crossover study was performed. Subjects were randomly assigned to one of the 2 sequences and alternately received four FDC soft capsules of atorvastatin/omega-3-acid ethyl esters (10/1000 mg) or a loose combination of atorvastatin tablets (10 mg × 4) and omega-3-acid ethyl ester soft capsules (1000 mg× 4) for four periods, each period accompanied by a high-fat meal. Serial blood samples were collected for PK analysis of atorvastatin, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). PK parameters were calculated by a non-compartmental analysis. The geometric mean ratio (GMR) and its 90% confidence interval (CI) of the FDC to the loose combination were calculated to compare PK parameters. Results: A total of 43 subjects completed the study as planned. The GMR (90% CI) of FDC to loose combination for maximum concentration (Cmax) and area under the time-concentration curve from zero to the last measurable point (AUClast) were 1.0931 (1.0054-1.1883) and 0.9885 (0.9588-1.0192) for atorvastatin, 0.9607 (0.9068-1.0178) and 0.9770 (0.9239-1.0331) for EPA, and 0.9961 (0.9127-1.0871) and 0.9634 (0.8830-1.0512) for DHA, respectively. The intra-subject variability for Cmax and AUClast of DHA was 30.8% and 37.5%, respectively, showing high variability. Both the FDC and the loose combination were safe and well tolerated. Conclusion: The FDC of atorvastatin and omega-3-acid ethyl esters showed comparable PK characteristics to the corresponding loose combination, offering a convenient therapeutic option for the treatment of dyslipidemia.

Pharmacokinetic and bioequivalence study of sugar-coated and film-coated eperisone tablets in healthy subjects: A randomized, open-label, three-way, reference-replicated crossover study
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OBJECTIVE: Eperisone hydrochloride is used in the treatment of musculoskeletal disorders as a muscle relaxant via blocking of calcium channels. In this study, we aimed to investigate the within-subject variability (CVwR) of reference eperisone formulation for highly-variable drugs and to perform bioequivalence study of two oral formulations (sugar- and film-coated tablets) of eperisone hydrochloride 50 mg in healthy subjects by reference-replicated crossover study. MATERIALS AND METHODS: 36 healthy Korean male subjects were recruited, and 33 subjects completed the study. A randomized, single-dose, open-label, three-way, three-sequence, reference formulation-replicated, crossover bioequivalence study was conducted to determine the bioequivalence of eperisone. Blood samples were collected before dosing and at 0.33, 0.67, 1, 1.5, 2, 2.5, 3, 4, 6, 8, and 12 hours after dosing. The plasma concentration of eperisone was determined using liquid chromatography-tandem mass spectrometry. RESULTS: The CVwR of eperisone reference product was 33.17% for AUCt and 50.21% for Cmax. The acceptance limit for Cmax was scaled to 0.6984 - 1.4319 according to CVwR. The 90% confidence intervals for the test/reference geometric mean ratio were 0.8275 - 1.1692 for AUCt and 0.7587 - 1.1652 for Cmax, which were within the accepted bioequivalence limits. Single oral doses of eperisone hydrochloride 50 mg were generally well tolerated in healthy adult subjects in this study. CONCLUSION: The newly developed film-coated tablet can be interchanged with the original sugar-coated tablet of eperisone. In addition, the reference scaling methods are more effective and economical than the classical method for assessing BE of HVDs.
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Preparation and evaluation of poly(2-hydroxyethyl aspartamide)-hexadecylamine-iron oxide for MR imaging of lymph nodes.

The purpose of this study was to synthesize biocompatible poly(2-hydroxyethyl aspartamide)-C16-iron oxide (PHEA-C16-iron oxide) nanoparticles and to evaluate their efficacy as a contrast agent for magnetic resonance imaging of lymph nodes. The PHEA-C16-iron oxide nanoparticles were synthesized by coprecipitation method. The core size of the PHEA-C16-iron oxide nanoparticles was about 5 to 7 nm, and the overall size of the nanoparticles was around 20, 60, and 150 nm in aqueous solution. The size of the nanoparticles was controlled by the amount of C16. The 3.0-T MRI signal intensity of a rabbit lymph node was effectively reduced after intravenous administration of PHEA-C16-iron oxide with the size of 20 nm. The in vitro and in vivo toxicity tests revealed the high biocompatibility of PHEA-C16-iron oxide nanoparticles. Therefore, PHEA-C16-iron oxide nanoparticles with 20-nm size can be potentially useful as T2-weighted MR imaging contrast agents for the detection of lymph nodes.

Biodistribution of newly synthesized PHEA-based polymer-coated SPION in Sprague Dawley rats as magnetic resonance contrast agent.

OBJECTIVES: The purpose of this study was to observe the pharmacokinetic behavior of newly synthesized biocompatible polymers based on polyhydroxyethylaspartamide (PHEA) to be used to coat an iron oxide core to make superparamagnetic iron oxide nanoparticles (SPION). MATERIALS AND METHODS: The isotopes [(14)C] and [(59)Fe] were used to label the polymer backbone (CLS) and iron oxide core (FLS), respectively. In addition, unradiolabeled cold superparamagnetic iron oxide nanoparticles (SPION/ULS) were synthesized to characterize particle size by dynamic light scattering, morphology by transmission electron microscopy, and in vivo magnetic resonance imaging (MRI). CLS and FLS were used separately to investigate the behavior of both the synthesized polymer and [Fe] in Sprague Dawley (SD) rats, respectively. Because radioactivity of the isotopes was different by ß for CLS and γ for FLS, synthesis of the samples had to be separately prepared. RESULTS: The mean particle size of the ULS was 66.1 nm, and the biodistribution of CLS concentrations in various organs, in rank order of magnitude, was liver > kidney > small intestine > other. The biodistribution of FLS concentrations was liver > spleen > lung > other. These rank orders show that synthesized SPION mainly accumulates in the liver. The differences in the distribution were caused by the SPION metabolism. Radiolabeled polymer was metabolized by the kidney and excreted mainly in the urine; [(59)Fe] was recycled for erythrocyte production in the spleen and excreted mainly in the feces. The MR image of the liver after intravenous injection demonstrated that [Fe] effectively accumulated in the liver and exhibited high-contrast enhancement on T2-weighted images. CONCLUSION: This newly synthesized, polymer-coated SPION appears to be a promising candidate for use as a liver-targeted, biocompatible iron oxide MR imaging agent.