Search results for "Cmax"
showing 10 items of 26 documents
Toward Biopredictive Dissolution for Enteric Coated Dosage Forms
2016
The aim of this work was to develop a phosphate buffer based dissolution method for enteric-coated formulations with improved biopredictivity for fasted conditions. Two commercially available enteric-coated aspirin products were used as model formulations (Aspirin Protect 300 mg, and Walgreens Aspirin 325 mg). The disintegration performance of these products in a physiological 8 mM pH 6.5 bicarbonate buffer (representing the conditions in the proximal small intestine) was used as a standard to optimize the employed phosphate buffer molarity. To account for the fact that a pH and buffer molarity gradient exists along the small intestine, the introduction of such a gradient was proposed for p…
A multilevel object-oriented modelling methodology for physiologically-based pharmacokinetics (PBPK): Evaluation with a semi-mechanistic pharmacokine…
2019
Abstract Background and objective The aims of this study are (i) to assess the predictive reliability of the physiologically based software PhysPK versus the well-known population approach software NONMEM for the cited semi-mechanistic PK model, (ii) to determine whether these modelling approaches are interchangeable and (iii) to compare acausal with causal modelling approaches in the framework of semi-mechanistic PK models. Methods A semi-mechanistic model was proposed, which assumed oral administration of a solid dosage form with a peripheral compartment and two active metabolites. The model incorporates intestinal transit, dissolution limited by solubility, variable efflux transporter ex…
In vitro evaluation of poloxamer in situ forming gels for bedaquiline fumarate salt and pharmacokinetics following intramuscular injection in rats
2019
Graphical abstract
Defining level A IVIVC dissolution specifications based on individual in vitro dissolution profiles of a controlled release formulation.
2018
Regulatory guidelines recommend that, when a level A IVIVC is established, dissolution specification should be established using averaged data and the maximum difference between AUC and Cmax between the reference and test formulations cannot be greater than 20%. However, averaging data assumes a loss of information and may reflect a bias in the results. The objective of the current work is to present a new approach to establish dissolution specifications using a new methodology (individual approach) instead of average data (classical approach). Different scenarios were established based on the relationship between in vitro-in vivo dissolution rate coefficient using a level A IVIVC of a cont…
Cerebrospinal fluid pharmacokinetics of ceftaroline in neurosurgical patients with an external ventricular drain
2019
IF 5.217; International audience; BackgroundOwing to its antibacterial properties, ceftaroline could be attractive for prevention or treatment of bacterial post-neurosurgical meningitis/ventriculitis. However, few data are available concerning its meningeal concentrations.ObjectivesTo investigate ceftaroline CSF pharmacokinetics in ICU patients with an external ventricular drain (EVD).MethodsPatients received a single 600 mg dose of ceftaroline as a 1 h intravenous infusion. Blood and CSF samples were collected before and 0.5, 1, 3, 6, 12 and 24 h after the end of the infusion. Concentrations were assayed in plasma and CSF by LC–MS/MS. A two-step compartmental pharmacokinetic analysis was c…
Nanosuspension Formulations for Low-Soluble Drugs: Pharmacokinetic Evaluation Using Spironolactone as Model Compound
2005
Various particle sizes of spironolactone as a model low solubility drug were formulated to yield micro-and nanosuspensions of the type solid lipid nanoparticles and DissoCubes. Seven oral and one i.v. formulations were tested in an in vivo pharmacokinetic study in rats with the aim of characterizing the bioavailability of spironolactone on the basis of its metabolites canrenone and 7-alpha-thiomethylspirolactone. In addition, a dose escalation study was carried out using nonmicronized spironolactone suspension as well as a nanosuspension type DissoCubes. On the basis of AUC as well as Cmax ratios, three groups of formulations were distinguished. The biggest improvement was seen with a solid…
Physiologically based metformin pharmacokinetics model of mice and scale-up to humans for the estimation of concentrations in various tissues
2020
Metformin is the primary drug for type 2 diabetes treatment and a promising candidate for other disease treatment. It has significant deviations between individuals in therapy efficiency and pharmacokinetics, leading to the administration of an unnecessary overdose or an insufficient dose. There is a lack of data regarding the concentration-time profiles in various human tissues that limits the understanding of pharmacokinetics and hinders the development of precision therapies for individual patients. The physiologically based pharmacokinetic (PBPK) model developed in this study is based on humans’ known physiological parameters (blood flow, tissue volume, and others). The missing tissue-s…
The Pharmacokinetics of Metronidazole and Gentamicin in a Single Preoperative Dose as Antibiotic Prophylaxis in Colorectal Surgery
2008
Objective: To describe, in patients undergoing colorectal surgery (CRS), the pharmacokinetics of a single, prophylactic preoperative dose of 1500 mg of metronidazole plus 240 mg gentamicin and measure its efficacy in accordance with the accepted pharmacodynamic and microbiological parameters. Method: Thirty-six patients undergoing CRS agreed to participate in the study. Three blood samples were taken from each. Cmax 15 minutes after finishing the infusion of the mixture, CfinIQ on finishing the surgery, and Cmin between 12 and 24 hours post-administration. The concentrations of metronidazole and gentamicin in each simple were measured and the pharmacokinetic parameters were estimated (dV-di…
Associations of ofatumumab exposure and treatment outcomes in patients with untreated CLL receiving chemoimmunotherapy
2016
Relationships between patient characteristics, ofatumumab pharmacokinetics, and treatment outcomes were investigated in this phase 2 trial of ofatumumab plus fludarabine and cyclophosphamide (FC) in untreated chronic lymphocytic leukemia. Patients were randomized 1:1 to receive 500 or 1000 mg ofatumumab (Cycle 1; 300 mg) plus FC every 4 weeks for six cycles. Median C(max) and C(trough) values were similar at Cycle 1 regardless of the ultimate clinical outcome. At later doses, these values were higher for patients with complete response (CR) than for other patients. Higher C(max) and C(trough) values at Cycles 3 and 6 were significantly associated with an increased likelihood of CR, whereas …
Correlations Between Ofatumumab Exposure and Treatment Outcomes for patients with Chronic Lymphocytic Leukemia (CLL) Treated with Frontline Ofatumuma…
2011
Abstract Abstract 1793 Introduction: Results: Seven pts (4 male) with a medianLittle is known about the pharmacokinetics (PK) and pharmacodynamics of CD20 monoclonal antibody (mAb) with chemotherapy in patients (pts) with CLL. Ofatumumab (O) is a human mAb targeting a membrane-proximal small-loop epitope on CD20 and mediates efficient complement-dependent cytotoxicity and antibody-dependent cell-mediated cytotoxicity. Safety and efficacy of O at 2 dose levels in combination with fludarabine and cyclophosphamide (FC) were evaluated in previously untreated pts with CLL. Relationship between O PK, baseline characteristics, and clinical outcomes were studied. Pts and Methods: Pts with active CL…