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- Garcia, Luna Prieto, et al.
(författare)
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Physiologically Based Pharmacokinetic Model of Itraconazole and Two of Its Metabolites to Improve the Predictions and the Mechanistic Understanding of CYP3A4 Drug-Drug Interactions
- 2018
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Ingår i: Drug Metabolism And Disposition. - : The American Society for Pharmacology and Experimental Therapeutics. - 0090-9556 .- 1521-009X. ; 46:10, s. 1420-1433
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Tidskriftsartikel (refereegranskat)abstract
- Physiologically based pharmacokinetic (PBPK) modeling for itraconazole using a bottom-up approach is challenging, not only due to complex saturable pharmacokinetics (PK) and the presence of three metabolites exhibiting CYP3A4 inhibition, but also because of discrepancies in reported in vitro data. The overall objective of this study is to provide a comprehensive mechanistic PBPK model for itraconazole in order to increase the confidence in its drug-drug interaction (DDI) predictions. To achieve this, key in vitro and in vivo data for itraconazole and its major metabolites were generated. These data were crucial to developing a novel bottom-up PBPK model in Simcyp (Simcyp Ltd., Certara, Sheffield, United Kingdom) for itraconazole and two of its major metabolites: hydroxy-itraconazole (OH-ITZ) and keto-itraconazole (keto-ITZ). Performance of the model was validated using prespecified acceptance criteria against different dosing regimens, formulations for 29 PK, and DDI studies with midazolam and other CYP3A4 substrates. The main outcome is an accurate PBPK model that simultaneously predicts the PK profiles of itraconazole, OH-ITZ, and keto-ITZ. In addition, itraconazole DDIs with midazolam and other CYP3A4 substrates were successfully predicted within a 2-fold error. Prediction precision and bias of DDI expressed as geometric mean fold error were for the area under the concentration-time curve and peak concentration, 1.06 and 0.96, respectively. To conclude, in this paper a comprehensive data set for itraconazole and its metabolites is provided that enables bottom-up mechanism-based PBPK modeling. The presented model is applicable for studying the contribution from the metabolites and allows improved assessments of itraconazole DDI.
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- Lennernäs, Bo, 1963, et al.
(författare)
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Sublingual administration of fentanyl to cancer patients is an effective treatment for breakthrough pain: results from a randomized phase II study.
- 2010
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Ingår i: Palliative medicine. - : SAGE Publications. - 1477-030X .- 0269-2163. ; 24:3, s. 286-93
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Tidskriftsartikel (refereegranskat)abstract
- In this study we evaluated the efficacy and tolerability of sublingual fentanyl (SLF) for breakthrough pain (BTP) in adult opioid-tolerant cancer patients. Patients received one dose of placebo, SLF 100, 200 and 400 microg in random order at four pain episodes. The primary efficacy endpoint was pain intensity difference (PID) from baseline. Twenty-seven patients received study medication. Overall PID increased significantly with SLF 400 microg versus placebo (8.57 mm, p <0.0001). Improvements were statistically different from placebo at 15 min (p = 0.005). SLF 100 and 200 microg showed a numerical trend towards improved pain relief. A dose that gave a clinically important reduction in pain (PID > 20 mm) was identified by 95% of patients. Reduced use of rescue medication (p < 0.001, SLF 400 microg) and improved global assessment of treatment (p = 0.0146, SLF 400 microg) confirmed these differences as clinically important. Nausea and dizziness were the most common treatment-related adverse effects. SLF appears to be a fast, effective and well-tolerated treatment for BTP.
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- Sjögren, Erik, et al.
(författare)
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In vivo methods for drug absorption - Comparative physiologies, model selection, correlations with in vitro methods (IVIVC), and applications for formulation/API/excipient characterization including food effects
- 2014
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Ingår i: European Journal of Pharmaceutical Sciences. - : Elsevier BV. - 0928-0987 .- 1879-0720. ; 57, s. 99-151
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Tidskriftsartikel (refereegranskat)abstract
- This review summarizes the current knowledge on anatomy and physiology of the human gastrointestinal tract in comparison with that of common laboratory animals (dog, pig, rat and mouse) with emphasis on in vivo methods for testing and prediction of oral dosage form performance. A wide range of factors and methods are considered in addition, such as imaging methods, perfusion models, models for predicting segmental/regional absorption, in vitro in vivo correlations as well as models to investigate the effects of excipients and the role of food on drug absorption. One goal of the authors was to clearly identify the gaps in today's knowledge in order to stimulate further work on refining the existing in vivo models and demonstrate their usefulness in drug formulation and product performance testing. (c) 2014 Elsevier B.V. All rights reserved.
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- Sjögren, Erik, et al.
(författare)
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Pharmacokinetics of an injectable modified-release 2-hydroxyflutamide formulation in the human prostate gland using a semiphysiologically based biopharmaceutical model.
- 2014
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Ingår i: Molecular pharmaceutics. - : American Chemical Society (ACS). - 1543-8392 .- 1543-8384. ; 11:9, s. 3097-111
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Tidskriftsartikel (refereegranskat)abstract
- The local distribution of 2-hydroxyflutamide (2-HOF) in prostate tissue after a single intraprostatic injection of a novel parenteral modified-release (MR) formulation in patients with localized prostate cancer was estimated using a semiphysiologically based biopharmaceutical model. Plasma concentration-time profiles for 2-HOF were acquired from a phase II study in 24 patients and the dissolution of the MR formulation was investigated in vitro. Human physiological values and the specific physicochemical properties of 2-HOF were obtained from the literature or calculated via established algorithms. A compartmental modeling approach was adopted for tissue and blood in the prostate gland, where the compartments were modeled as a series of concentric spherical shells contouring the centrally positioned depot formulation. Discrete fluid connections between the blood compartments were described by the representative flow of blood, whereas the mass transport of drug from tissue to tissue and tissue to blood was described by a one-dimensional diffusion approximation. An empirical dissolution approach was adopted for the release of 2-HOF from the formulation. The model adequately described the plasma concentration-time profiles of 2-HOF. Predictive simulations indicated that the local tissue concentration of 2-HOF within a distance of 5 mm from the depot formulation was approximately 40 times higher than that of unbound 2-HOF in plasma. The simulations also indicated that spreading the formulation throughout the prostate gland would expose more of the gland and increase the overall release rate of 2-HOF from the given dose. The increased release rate would initially increase the tissue and plasma concentrations but would also reduce the terminal half-life of 2-HOF in plasma. Finally, an in vitro-in vivo correlation of the release of 2-HOF from the parenteral MR formulation was established. This study shows that intraprostatic 2-HOF concentrations are significantly higher than systemic plasma concentrations and that increased distribution of 2-HOF throughout the gland, using strategic imaging-guided administration, is possible. This novel parenteral MR formulation, thus, facilitates good pharmacological effect while minimizing the risk of side effects.
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- Tammela, T L, et al.
(författare)
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An Intraprostatic Modified Release Formulation of Antiandrogen 2-Hydroxyflutamide for Localized Prostate Cancer
- 2017
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Ingår i: Journal of Urology. - : Ovid Technologies (Wolters Kluwer Health). - 0022-5347 .- 1527-3792. ; 198:6, s. 1333-1339
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To investigate tolerability, safety and antitumor effects of a novel intra-prostatic depot formulation of antiandrogen 2-hydroxyflutamide (2-HOF in NanoZolid(®)) in men with localized prostate cancer (PCa).MATERIALS AND METHODS: Two clinical trials, LPC-002 and LPC-003, were conducted on a total of 47 men. The formulation was injected transrectally into the prostate with ultrasound guidance. In LPC-002 the effects on prostate specific antigen (PSA) and prostate volume (PV) were measured over 6 months on 24 patients. In LPC-003, antitumor effects were evaluated with histopathology, magnetic resonance imaging (MRI) including spectroscopy (MRS) during 6 or 8 weeks on 23 patients. In both studies, testosterone and 2-HOF in plasma were measured, as well as quality-of-life parameters.RESULTS: In LPC-002 (mean dose 690 mg) a reduction in PSA and PV was observed. The nadir values for PSA and PV were on average 24.9 % and 14.0 % below baseline, respectively. When increasing the dose in LPC-003 (920 mg and 1740 mg), the average PSA dropped 16 % and 23 %, respectively, after 6 and 8 weeks. MRI/MRS showed morphological changes and a global drop in metabolite concentrations following treatment indicating an antitumor response. The injections did not result in hormone related side effects. In total, three serious adverse events were reported, all resolved by oral antibiotic treatment.CONCLUSIONS: The intraprostatic injections of 2-HOF depot formulations indicated anti-tumor effects and proved safe and tolerable. However, for better anti-cancer effects higher doses and better dose distribution are suggested.
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