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Omeprazole blocks the gastric H+ /K+ adenosine triphosphatase, thus inhibiting gastric acid secretion, and is metabolized by cytochrome P450 (CYP) 2C19. Due to the physiological changes in the elderly, there are different pharmacokinetic consequences compared to young people. The aim of this study was to evaluate the pharmacokinetic profiles of omeprazole in 15 elderly participants according to the CYP2C19 genotype. The concentration-time profiles of omeprazole and its metabolites, 5-hydroxy (5-OH) omeprazole and omeprazole sulfone, were similar between the CYP2C19 extensive metabolizer (EM) and intermediate metabolizer groups. In contrast, when comparing the EM group and CYP2C19 poor metabolizer (PM) group, the EM/PM geometric mean ratio (95% confidence interval) of area under the plasma concentration-time curve from time of dosing to the last measurable concentration was 0.52 (0.27-1.01) and that of the IM group was 0.71 (0.32-1.59), indicating that the exposure of omeprazole in the PM group was increased. The exposure of 5-OH omeprazole was significantly decreased in the PM group when compared to the EM group, with an EM/PM geometric mean ratio (95% confidence interval) of 2.20 (1.50-3.22). In conclusion, the tendency of drug exposure according to the CYP2C19 genotype in the elderly and young adults was similar in that the exposure level was highest in the PM group. However, when compared to young adults, the difference between the genotype groups was smaller in the elderly.

Hypertension is more effectively treated with coadministration of 2 or more antihypertensive drugs than with high-dose monotherapy. Therefore, calcium channel blockers, angiotensin II receptor blockers, and thiazides are coadministered to treat hypertension. The objective of this study was to compare the pharmacokinetic (PK) profiles of HCP1401, a fixed-dose combination of amlodipine 5 mg, losartan 100 mg, and chlorthalidone 25 mg, with the separate components (loose combination) of amlodipine/losartan 5/100 mg and chlorthalidone 25 mg. A randomized, open-label, single-dose, 2-way crossover study was conducted. Blood samples for amlodipine and chlorthalidone were collected for up to 144 hours after dosing, whereas those for losartan were collected up to 48 hours after dosing. The PK parameters of these drugs were calculated using a noncompartmental method. Sixty subjects completed the study. The geometric mean ratios and 90% confidence intervals of maximum plasma concentration and area under the concentration-time curve to the last measurable point for amlodipine, losartan, and chlorthalidone were within the conventional bioequivalence range of 0.80 to 1.25. There were no clinically significant changes in safety assessments, and the treatments were well tolerated. The PK characteristics and tolerability profiles of a single oral FDC of amlodipine, losartan, and chlorthalidone were equivalent to those of individual tablets in a loose combination.

Inseung Jeon,1,* Jaeseong Oh,1,* Yu-Kyung Kwon,2 Seo Hyun Yoon,1 Joo-Youn Cho,1 In-Jin Jang,1 Kyung-Sang Yu,1 SeungHwan Lee1 1Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, Republic of Korea; 2Department of Clinical Research, Chong Kun Dang, Seoul, Republic of Korea*These authors contributed equally to this workCorrespondence: SeungHwan LeeDepartment of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of KoreaTel +82 2 2072 2343Fax +82 2 742 9252Email leejh413@snu.ac.krIntroduction: Darbepoetin alfa (NESP® and ARANESP®) has a sustained erythropoietic activity with a longer half-life than conventional recombinant human erythropoietin. CKD-11101 is under clinical development as a biosimilar of darbepoetin alfa. The purpose of this study was to compare the pharmacokinetic (PK), pharmacodynamic (PD), and tolerability profiles of CKD-11101 with those of reference drug in healthy subjects.Methods: This study was performed in two parts for healthy subjects. In each period, CKD-11101 and reference, both at 60 μg, were administered via intravenous (IV) or subcutaneous (SC) route of administration.Results: After both IV or SC dose, the geometric mean ratio (GMR) of CKD-11101 to reference drug and its 90% confidence intervals (CIs) for Cmax, AUC0–last and AUC0–∞ were all within 0.8– 1.25. No statistically significant differences were noted in the maximum baseline adjusted reticulocyte count or the area under the baseline adjusted reticulocyte count-time between the CKD-11101 and reference drug after IV or SC dose (all p-value> 0.05). Both CKD-11101 and reference drug were generally well tolerated.Discussion: After a single IV or SC dose, the CKD-11101 was well tolerated and showed comparable PK and PD characteristics with reference drug.Keywords: pharmacokinetics, pharmacodynamics, biosimilar, darbepoetin alfa

Introduction Darbepoetin alfa (NESP® and ARANESP®) has a sustained erythropoietic activity with a longer half-life than conventional recombinant human erythropoietin. CKD-11101 is under clinical development as a biosimilar of darbepoetin alfa. The purpose of this study was to compare the pharmacokinetic (PK), pharmacodynamic (PD), and tolerability profiles of CKD-11101 with those of reference drug in healthy subjects. Methods This study was performed in two parts for healthy subjects. In each period, CKD-11101 and reference, both at 60 μg, were administered via intravenous (IV) or subcutaneous (SC) route of administration. Results After both IV or SC dose, the geometric mean ratio (GMR) of CKD-11101 to reference drug and its 90% confidence intervals (CIs) for Cmax, AUC0–last and AUC0–∞ were all within 0.8–1.25. No statistically significant differences were noted in the maximum baseline adjusted reticulocyte count or the area under the baseline adjusted reticulocyte count-time between the CKD-11101 and reference drug after IV or SC dose (all p-value>0.05). Both CKD-11101 and reference drug were generally well tolerated. Discussion After a single IV or SC dose, the CKD-11101 was well tolerated and showed comparable PK and PD characteristics with reference drug.

Fixed-dose combination (FDC) drugs with various dose combinations for the treatment of type 2 diabetes mellitus and dyslipidemia are currently in demand. We compared the pharmacokinetic (PK) profiles of the rosuvastatin/metformin sustained-release (10/1000 mg) FDC and separate tablets and evaluated the effect of food by randomized, open-label, 3-period, 6-sequence crossover studies conducted in healthy male subjects. Subjects were randomly assigned to one of the following treatments: separate tablets of 10 mg rosuvastatin and 1000 mg metformin sustained release in the fed state and the FDC in the fasted and fed states. PK samples were collected up to 72 hours postdose for rosuvastatin, N-desmethyl rosuvastatin, and metformin. The PK parameters were determined using a noncompartmental method, and the geometric mean ratio (GMR) and the 90% confidence interval (CI) of the treatments were calculated. A total of 35 subjects completed the study. The GMR and 90%CI of the peak concentration (Cmax ) and area under the plasma concentration-time curve from time zero to the last measurable concentration (AUClast ) of the FDC and the separate tablets were within the bioequivalence criteria (0.8-1.25) for both rosuvastatin and metformin. The effect of food was statistically significant for both rosuvastatin and metformin but not expected to be of clinical significance.

To build a physiologically based pharmacokinetic (PBPK) model for fimasartan, amlodipine, and hydrochlorothiazide, and to investigate the drug–drug interaction (DDI) potentials. The PBPK model of each drug was developed using Simcyp software (Version 15.0), based on the information obtained from literature sources and in vitro studies. The predictive performance of the model was assessed by comparing the predicted PK profiles and parameters with the observed data collected from healthy subjects after multiple oral doses of fimasartan, amlodipine, and hydrochlorothiazide. The DDI potentials after co-administration of three drugs were simulated using the final model. The predicted-to-observed ratios of all the pharmacokinetic parameters met the acceptance criterion. The PBPK model predicted no significant DDI when fimasartan was co-administered with amlodipine or hydrochlorothiazide, which is consistent with the observed clinical data. In the simulation of DDI at steady-state after co-administration of three drugs, the model predicted that fimasartan exposure would be increased by ~24.5%, while no changes were expected for the exposures of amlodipine and hydrochlorothiazide. The developed PBPK model adequately predicted the pharmacokinetics of fimasartan, amlodipine, and hydrochlorothiazide, suggesting that the model can be used to further investigate the DDI potential of each drug.