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Spampinato RA, Marin-Cuartas M, van Kampen A, Fahr F, Sieg F, Strotdrees E, Jahnke C, Klaeske K, Wiesner K, Morningstar JE, Nagata Y, Izquierdo-Garcia D, Dieterlen MT, Norris RA, Levine RA, Paetsch I, Borger MA. Left ventricular fibrosis and CMR tissue characterization of papillary muscles in mitral valve prolapse patients. Int J Cardiovasc Imaging 2024; 40:213-224. [PMID: 37891450 DOI: 10.1007/s10554-023-02985-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 10/11/2023] [Indexed: 10/29/2023]
Abstract
PURPOSE Mitral valve prolapse (MVP) is associated with left ventricle (LV) fibrosis, including the papillary muscles (PM), which is in turn linked to malignant arrhythmias. This study aims to evaluate comprehensive tissue characterization of the PM by cardiovascular magnetic resonance (CMR) imaging and its association with LV fibrosis observed by intraoperative biopsies. METHODS MVP patients with indication for surgery due to severe mitral regurgitation (n = 19) underwent a preoperative CMR with characterization of the PM: dark-appearance on cine, T1 mapping, conventional bright blood (BB) and dark blood (DB) late gadolinium enhancement (LGE). CMR T1 mapping was performed on 21 healthy volunteers as controls. LV inferobasal myocardial biopsies were obtained in MVP patients and compared to CMR findings. RESULTS MVP patients (54 ± 10 years old, 14 male) had a dark-appearance of the PM with higher native T1 and extracellular volume (ECV) values compared with healthy volunteers (1096 ± 78ms vs. 994 ± 54ms and 33.9 ± 5.6% vs. 25.9 ± 3.1%, respectively, p < 0.001). Seventeen MVP patients (89.5%) had fibrosis by biopsy. BB-LGE + in LV and PM was identified in 5 (26.3%) patients, while DB-LGE + was observed in LV in 9 (47.4%) and in PM in 15 (78.9%) patients. DB-LGE + in PM was the only technique that showed no difference with detection of LV fibrosis by biopsy. Posteromedial PM was more frequently affected than the anterolateral (73.7% vs. 36.8%, p = 0.039) and correlated with biopsy-proven LV fibrosis (Rho 0.529, p = 0.029). CONCLUSIONS CMR imaging in MVP patients referred for surgery shows a dark-appearance of the PM with higher T1 and ECV values compared with healthy volunteers. The presence of a positive DB-LGE at the posteromedial PM by CMR may serve as a better predictor of biopsy-proven LV inferobasal fibrosis than conventional CMR techniques.
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Affiliation(s)
- Ricardo A Spampinato
- Department of Cardiac Surgery, University, Leipzig Heart Center, Struempellstrasse 39, 04289, Leipzig, Germany.
| | - Mateo Marin-Cuartas
- Department of Cardiac Surgery, University, Leipzig Heart Center, Struempellstrasse 39, 04289, Leipzig, Germany
| | - Antonia van Kampen
- Department of Cardiac Surgery, University, Leipzig Heart Center, Struempellstrasse 39, 04289, Leipzig, Germany
- Division of Cardiac Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Florian Fahr
- Department of Cardiac Surgery, University, Leipzig Heart Center, Struempellstrasse 39, 04289, Leipzig, Germany
| | - Franz Sieg
- Department of Cardiac Surgery, University, Leipzig Heart Center, Struempellstrasse 39, 04289, Leipzig, Germany
| | - Elfriede Strotdrees
- Department of Cardiac Surgery, University, Leipzig Heart Center, Struempellstrasse 39, 04289, Leipzig, Germany
| | - Cosima Jahnke
- Department of Cardiology and Electrophysiology, Leipzig Heart Center, Leipzig, Germany
| | - Kristin Klaeske
- Department of Cardiac Surgery, University, Leipzig Heart Center, Struempellstrasse 39, 04289, Leipzig, Germany
| | - Karoline Wiesner
- Department of Cardiac Surgery, University, Leipzig Heart Center, Struempellstrasse 39, 04289, Leipzig, Germany
| | - Jordan E Morningstar
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Yasufumi Nagata
- Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - David Izquierdo-Garcia
- The Institute for Innovation in Imaging, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Maja-Theresa Dieterlen
- Department of Cardiac Surgery, University, Leipzig Heart Center, Struempellstrasse 39, 04289, Leipzig, Germany
| | - Russell A Norris
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Robert A Levine
- Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Ingo Paetsch
- Department of Cardiology and Electrophysiology, Leipzig Heart Center, Leipzig, Germany
| | - Michael A Borger
- Department of Cardiac Surgery, University, Leipzig Heart Center, Struempellstrasse 39, 04289, Leipzig, Germany
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Spampinato RA, Marin-Cuartas M, Kampen A, Fahr F, Sieg F, Strotdrees E, Jahnke C, Klaeske K, Wiesner K, Morningstar JE, Nagata Y, Izquierdo-Garcia D, Dieterlen MT, Norris RA, Levine RA, Paetsch I, Borger MA. Left Ventricular Fibrosis and CMR Tissue Characterization of Papillary Muscles in Mitral Valve Prolapse Patients. Res Sq 2023:rs.3.rs-2936590. [PMID: 37292932 PMCID: PMC10246246 DOI: 10.21203/rs.3.rs-2936590/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Purpose Mitral valve prolapse (MVP) is associated with left ventricle (LV) fibrosis, including the papillary muscles (PM), which is in turn linked to malignant arrhythmias. This study aims to evaluate comprehensive tissue characterization of the PM by cardiovascular magnetic resonance (CMR) imaging and its association with LV fibrosis observed by intraoperative biopsies. Methods MVP patients with indication for surgery due to severe mitral regurgitation (n=19) underwent a preoperative CMR with characterization of the PM: dark-appearance on cine, T1 mapping, conventional bright blood (BB) and dark blood (DB) late gadolinium enhancement (LGE). CMR T1 mapping was performed on 21 healthy volunteers as controls. LV inferobasal myocardial biopsies were obtained in MVP patients and compared to CMR findings. Results MVP patients (54±10 years old, 14 male) had a dark-appearance of the PM with higher native T1 and extracellular volume (ECV) values compared with healthy volunteers (1096±78ms vs 994±54ms and 33.9±5.6% vs 25.9±3.1%, respectively, p<0.001). Seventeen MVP patients (89.5%) had fibrosis by biopsy. BB-LGE+ in LV and PM was identified in 5 (26.3%) patients, while DB-LGE+ was observed in LV in 9 (47.4%) and in PM in 15 (78.9%) patients. DB-LGE+ in PM was the only technique that showed no difference with detection of LV fibrosis by biopsy. Posteromedial PM was more frequently affected than the anterolateral (73.7% vs 36.8%, p=0.039) and correlated with biopsy-proven LV fibrosis (Rho 0.529, p=0.029). Conclusions CMR imaging in MVP patients referred for surgery shows a dark-appearance of the PM with higher T1 and ECV values compared with healthy volunteers. The presence of a positive DB-LGE at the posteromedial PM by CMR may serve as a better predictor of biopsy-proven LV inferobasal fibrosis than conventional CMR techniques.
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Nozdrzykowski M, Fahr F, Schulz U, Borger MA, Saeed D. Extrakorporaler Life Support bei primärem Transplantatversagen: Welche Optionen bestehen? Z Herz- Thorax- Gefäßchir 2023. [DOI: 10.1007/s00398-022-00546-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Nozdrzykowski M, Fahr F, Schulz U, Jawad K, Huhn S, Al-Naamani A, Eifert S, Garbade J, Borger M, Saeed D. Stroke and Pump Thrombosis following LVAD Implantation: Impact of the Implantation Approach. Thorac Cardiovasc Surg 2022. [DOI: 10.1055/s-0042-1742845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
| | - F. Fahr
- Herzzentrum Leipzig, Leipzig, Deutschland
| | - U. Schulz
- Heart Center Leipzig, Leipzig, Deutschland
| | - K. Jawad
- Heart Center Leipzig, Leipzig, Deutschland
| | - S. Huhn
- Herzzentrum Leipzig, Leipzig, Deutschland
| | | | - S. Eifert
- Heart Center Leipzig, Leipzig, Deutschland
| | - J. Garbade
- Herzchirurgie, Klinikum Links der Weser, Bremen, Deutschland
| | - M. Borger
- Herzzentrum Leipzig, Leipzig, Deutschland
| | - D. Saeed
- Heart Center Leipzig, Leipzig, Deutschland
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Jawad K, Sandri M, Feder S, Al-Naamani A, Fahr F, Nozdrzykowski M, Bireta C, Eifert S, Correia JC, Schulz U, Borger M, Saeed D. Percutaneous Decommissioning of Left Ventricular Assist Device: Is This a Safe Procedure? Thorac Cardiovasc Surg 2022. [DOI: 10.1055/s-0042-1742841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- K. Jawad
- Heart Center Leipzig, Leipzig, Deutschland
| | - M. Sandri
- Heart Center Leipzig, Leipzig, Deutschland
| | - S. Feder
- Heart Center Leipzig, Leipzig, Deutschland
| | | | - F. Fahr
- Heart Center Leipzig, Leipzig, Deutschland
| | | | - C. Bireta
- Heart Center Leipzig, Leipzig, Deutschland
| | - S. Eifert
- Heart Center Leipzig, Leipzig, Deutschland
| | | | - U. Schulz
- Heart Center Leipzig, Leipzig, Deutschland
| | - M. Borger
- Heart Center Leipzig, Leipzig, Deutschland
| | - D. Saeed
- Heart Center Leipzig, Leipzig, Deutschland
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Spampinato RA, Jahnke C, Crelier G, Lindemann F, Fahr F, Czaja-Ziolkowska M, Sieg F, Strotdrees E, Hindricks G, Borger MA, Paetsch I. Quantification of regurgitation in mitral valve prolapse with four-dimensional flow cardiovascular magnetic resonance. J Cardiovasc Magn Reson 2021; 23:87. [PMID: 34233708 PMCID: PMC8265147 DOI: 10.1186/s12968-021-00783-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Accepted: 05/26/2021] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Four-dimensional cardiovascular magnetic resonance (CMR) flow assessment (4D flow) allows to derive volumetric quantitative parameters in mitral regurgitation (MR) using retrospective valve tracking. However, prior studies have been conducted in functional MR or in patients with congenital heart disease, thus, data regarding the usefulness of 4D flow CMR in case of a valve pathology like mitral valve prolapse (MVP) are scarce. This study aimed to evaluate the clinical utility of cine-guided valve segmentation of 4D flow CMR in assessment of MR in MVP when compared to standardized routine CMR and transthoracic echocardiography (TTE). METHODS Six healthy subjects and 54 patients (55 ± 16 years; 47 men) with MVP were studied. TTE severity grading used a multiparametric approach resulting in mild/mild-moderate (n = 12), moderate-severe (n = 12), and severe MR (n = 30). Regurgitant volume (RVol) and regurgitant fraction (RF) were also derived using standard volumetric CMR and 4D flow CMR datasets with direct measurement of regurgitant flow (4DFdirect) and indirect calculation using the formula: mitral valve forward flow - left ventricular outflow tract stroke volume (4DFindirect). RESULTS There was moderate to strong correlation between methods (r = 0.59-0.84, p < 0.001), but TTE proximal isovelocity surface area (PISA) method showed higher RVol as compared with CMR techniques (PISA vs. CMR, mean difference of 15.8 ml [95% CI 9.9-21.6]; PISA vs. 4DFindirect, 17.2 ml [8.4-25.9]; PISA vs. 4DFdirect, 27.9 ml [19.1-36.8]; p < 0.001). Only indirect CMR methods (CMR vs. 4DFindirect) showed moderate to substantial agreement (Lin's coefficient 0.92-0.97) without significant bias (mean bias 1.05 ± 26 ml [- 50 to 52], p = 0.757). Intra- and inter-observer reliability were good to excellent for all methods (ICC 0.87-0.99), but with numerically lower coefficient of variation for indirect CMR methods (2.5 to 12%). CONCLUSIONS In the assessment of patients with MR and MVP, cine-guided valve segmentation 4D flow CMR is feasible and comparable to standard CMR, but with lower RVol when TTE is used as reference. 4DFindirect quantification has higher intra- and inter-technique agreement than 4DFdirect quantification and might be used as an adjunctive technique for cross-checking MR quantification in MVP.
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Affiliation(s)
- Ricardo A Spampinato
- Department of Cardiac Surgery, Heart Center Leipzig at University of Leipzig, Struempellstrasse 39, 04289, Leipzig, Germany.
| | - Cosima Jahnke
- Department of Cardiology and Electrophysiology, Heart Center Leipzig at University of Leipzig, Struempellstrasse 39, 04289, Leipzig, Germany
| | - Gerard Crelier
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - Frank Lindemann
- Department of Cardiology and Electrophysiology, Heart Center Leipzig at University of Leipzig, Struempellstrasse 39, 04289, Leipzig, Germany
| | - Florian Fahr
- Department of Cardiac Surgery, Heart Center Leipzig at University of Leipzig, Struempellstrasse 39, 04289, Leipzig, Germany
| | - Monika Czaja-Ziolkowska
- Department of Cardiology and Electrophysiology, Heart Center Leipzig at University of Leipzig, Struempellstrasse 39, 04289, Leipzig, Germany
| | - Franz Sieg
- Department of Cardiac Surgery, Heart Center Leipzig at University of Leipzig, Struempellstrasse 39, 04289, Leipzig, Germany
| | - Elfriede Strotdrees
- Department of Cardiac Surgery, Heart Center Leipzig at University of Leipzig, Struempellstrasse 39, 04289, Leipzig, Germany
| | - Gerhard Hindricks
- Department of Cardiology and Electrophysiology, Heart Center Leipzig at University of Leipzig, Struempellstrasse 39, 04289, Leipzig, Germany
| | - Michael A Borger
- Department of Cardiac Surgery, Heart Center Leipzig at University of Leipzig, Struempellstrasse 39, 04289, Leipzig, Germany
| | - Ingo Paetsch
- Department of Cardiology and Electrophysiology, Heart Center Leipzig at University of Leipzig, Struempellstrasse 39, 04289, Leipzig, Germany
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Al-Naamani A, Fahr F, Khan A, Bireta C, Nozdrzykowski M, Feder S, Deshmukh N, Jubeh M, Eifert S, Jawad K, Schulz U, Borger MA, Saeed D. Minimally invasive ventricular assist device implantation. J Thorac Dis 2021; 13:2010-2017. [PMID: 33841987 PMCID: PMC8024790 DOI: 10.21037/jtd-20-1492] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Durable mechanical circulatory support (MCS) systems are established therapy option in patients with end-stage heart failure, with increasing importance during the last years due to donor organ shortage. Left ventricular assist devices (LVADs) are traditionally implanted through median sternotomy (MS). However, improvement in the pump designs during the last years led to evolvement of new surgical approaches that aim to reduce the invasiveness of the procedure. Numerous reports and studies have shown the viability and possible advantages of less-invasive approach compared to the sternotomy approach. The less invasive implant strategies for LVADs, while vague in definition, are characterized by minimizing surgical trauma and if possible, cardio-pulmonary bypass related complications. Usually it involves minimizing or completely avoiding sternal trauma, avoiding heart luxation while simultaneously leaving the major part of pericardium intact. There is no consensus between the centers regarding the ideal approach for LVAD implantation. Some centers, like our center, perform by default VAD implantation using less invasive approach in almost all patients and some centers use only sternotomy approach. The aim of this review article is to shed light on the currently available less invasive options of LVAD implantation, with particular focus on the centrifugal pumps, and their possible advantages compared to traditional sternotomy approach.
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Affiliation(s)
- Ameen Al-Naamani
- Department of Cardiac Surgery, Heart Center, University of Leipzig, Leipzig, Germany
| | - Florian Fahr
- Department of Cardiac Surgery, Heart Center, University of Leipzig, Leipzig, Germany
| | - Asim Khan
- Department of Cardiology, Heart Center, University of Leipzig, Leipzig, Germany
| | - Christian Bireta
- Department of Cardiac Surgery, Heart Center, University of Leipzig, Leipzig, Germany
| | - Michael Nozdrzykowski
- Department of Cardiac Surgery, Heart Center, University of Leipzig, Leipzig, Germany
| | - Stefan Feder
- Department of Cardiac Surgery, Heart Center, University of Leipzig, Leipzig, Germany
| | - Nikhil Deshmukh
- Department of Cardiac Surgery, Heart Center, University of Leipzig, Leipzig, Germany
| | - Manal Jubeh
- Department of Cardiac Surgery, Heart Center, University of Leipzig, Leipzig, Germany
| | - Sandra Eifert
- Department of Cardiac Surgery, Heart Center, University of Leipzig, Leipzig, Germany
| | - Khalil Jawad
- Department of Cardiac Surgery, Heart Center, University of Leipzig, Leipzig, Germany.,Cardiac Surgery, Peter Munk Cardiac Center, University of Toronto, Toronto, Canada
| | - Uwe Schulz
- Department of Cardiac Surgery, Heart Center, University of Leipzig, Leipzig, Germany
| | - Michael A Borger
- Department of Cardiac Surgery, Heart Center, University of Leipzig, Leipzig, Germany
| | - Diyar Saeed
- Department of Cardiac Surgery, Heart Center, University of Leipzig, Leipzig, Germany
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Neubert R, Fahr F, Mäder C, Lücke L, Fries G, Rostock G. Use of an in vitro absorption model system for predicting sustained release of verapamil. Arzneimittelforschung 1992; 42:1098-100. [PMID: 1445475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
It is shown that it is possible to characterize sustained release formulations in vitro using not only dissolution data but also an absorption model system. The mean dissolution time (MDT) has been shown to be a suitable parameter for evaluating sustained release formulations in vitro. t1/2 and mean residence time (MRT) have been shown to be convenient pharmacokinetic parameters for characterizing sustained release formulations. For comparing in vitro and in vivo results the quotients MDT normal/MDT retard and MRT normal/MRT retard do seem to be useful.
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Affiliation(s)
- R Neubert
- Department of Pharmacy, Martin-Luther-University, Halle/Saale, Fed. Rep. of Germany
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Fahr F, Neubert R, Hahn HJ, Pönicke K. [Improvement of the disolution behavior of problem drugs. 22. Preformulations of AR 12463 in absorption models]. Pharmazie 1991; 46:673. [PMID: 1798735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- F Fahr
- Sektion Pharmazie, Martin-Luther-Universität Halle-Wittenberg
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10
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Fahr F, Zessin G, Kala H, Fries G. [Improvement of the solubility behavior of problem drugs. 20. The effect of pharmaceutical excipients on the wetability of iomeglamic acid]. Pharmazie 1989; 44:576-7. [PMID: 2594830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- F Fahr
- Sektion Pharmazie Martin-Luther-Universität Halle-Wittenberg
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11
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Fahr F, Kala H, Hückel T, Fries G. [Improvement of the solubility of problem drugs. 17. Processing of iomeglamic acid/methylcellulose coprecipitates in tablets]. Pharmazie 1988; 43:216. [PMID: 3380870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- F Fahr
- Sektion Pharmazie der Martin-Luther-Universität Halle-Wittenberg
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13
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Fahr F, Kala H, Fries G, Helbig G. [Improvement of the solubility of problem drugs. 18. Iomeglamic acid-PVA effervescent powder]. Pharmazie 1988; 43:217. [PMID: 3380871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- F Fahr
- Sektion Pharmazie der Martin-Luther-Universität Halle-Wittenberg
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Köttig S, Hahn HJ, Fahr F, Flöther FU. [Evaluation of retard drug forms with special reference to their therapeutic aspects]. Pharmazie 1988; 43:58-64. [PMID: 3287399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The useful development and application of controlled-release dosage forms is an important possibility to improve the pharmacotherapy of many diseases. However, according to the present social conditions of reproduction the introduction of a new drug has to be directed not only to a high therapeutic benefit but also to an increased social efficiency i.e., to an improvement of cost-benefit-relation. In the present study, therefore, the effect of using controlled-release dosage forms on the development of social efficiency is discussed. Basing on a comprehensive estimation of the therapeutic efficiency (therapeutic advantages and disadvantages) of controlled-release dosage forms the criteria of cost and benefit being of importance for a complex evaluation of efficiency are described.
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Affiliation(s)
- S Köttig
- Sektion Pharmazie, Martin-Luther-Universität Halle-Wittenberg, Halle, Saale
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15
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Fahr F, Kala H, Pollandt P, Fries G, Hückel T. [Improvement of the solubility of problem drugs. 15. Alteration of iomeglamic acid-methylcellulose (MH 300)-PEG 6000 coprecipitates]. Pharmazie 1987; 42:552-3. [PMID: 3432340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- F Fahr
- Sektion Pharmazie, Martin-Lůther-Universität Halle-Wittenberg
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16
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Fahr F, Kala H, Pollandt P, Hückel T, Fries G. [Improvement of the solubility of problem drugs. 15. X-ray diffraction of iomeglamic acid-methylcellulose (MH 300)-PEG 6000-coprecipitate]. Pharmazie 1987; 42:554. [PMID: 3432342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- F Fahr
- Sektion Pharmazie, Martin-Luther-Universität Halle-Wittenberg
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17
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Fahr F, Kala H, Hückel T, Fries G. [The improvement of solubility behavior of problem drugs. 14. Effect of properties of methylcellulose-coprecipitates on solubility]. Pharmazie 1987; 42:275. [PMID: 3615564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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18
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Fahr F, Neubert R, Fürst W, Kala H, Masthoff F. [Improvement of the solubility behavior of problem drugs. 9. In vitro absorption studies using melting solidification products of iomeglamic acid]. Pharmazie 1986; 41:855-6. [PMID: 3575388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
By means of the absorption apparatus according to Fürst and Neubert the solid dispersions of the iomeglamic acid were studied with regard to their in vitro absorption properties. All products showed better half lives of transport in relation to the pure compound. This was in correlation to the solubility parameters.
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Fahr F, Kala H, Masthoff F, Fries G. [Improvement of the dissolution behavior of problem drugs. 11. DTA iomeglamic-PVP 25 copreciptates]. Pharmazie 1986; 41:517. [PMID: 3774866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Kala H, Haack U, Fahr F, Pollandt P. [Crystallographic behavior of carbamazepine preparations under compression pressure]. Pharmazie 1986; 41:61-2. [PMID: 3960954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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21
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Mank R, Zessin G, Fahr F. [Preparations of matrix tablets from a polyacrylate base]. Pharmazie 1986; 41:42-4. [PMID: 3960947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The authors report with the example of the model drug, caffeine, on the preparation and investigation of matrix tablets on the basis of acrylates. The release values obtained were analysed by the equations of Higuchi and also Noyes-Whitney. It was demonstrated, that the polymer composition and the drug content in the tablets have an influence on the release of the drug.
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22
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Zessin G, Fahr F, Mank R. [The control of drug release of heavy-soluble, weak basic drugs in matrix tablets using the example of medazepam]. Pharmazie 1986; 41:39-42. [PMID: 2870512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
According to ideas about the diffusion layer in the process of dissolving solids the release of medazepam as a model substance for heavy-soluble, weak alkaline substances is modified by incorporation of solid acids of different solubility and dissociation rate into the matrix. The determination of the solubility and a "virtual" pH-value within the matrix tablets leads to the evaluation of the liberation. A relatively continuous release of medazepam following different pH-values in the medium was obtained by microencapsulation of the citrus acid incorporated. Using the ideas of the diffusion layer to explain the conditions within the matrix it becomes possible to control and influence the drug release from the matrix tablet.
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Fahr F, Kala H, Pollandt P, Zessin G. [The improvement of solubility behavior of problem drugs. 7. Iomeglamic acid-mannitol-melting viscosity products]. Pharmazie 1985; 40:733-4. [PMID: 3936061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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24
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Fahr F, Kala H, Pollandt P, Wenzel U, Masthoff F. [Improvement of the solubility of problem drugs. 1. Production of iomeglamic acid fused and solidified products]. Pharmazie 1985; 40:408-9. [PMID: 4034650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The insoluble X-ray diagnostic iomeglamic acid could be converted to a more soluble modification by melting and solidifying it in liquid nitrogen. The amorphous state is proved by X-ray diffraction and differential thermal analysis. During storage, recristallisation of the product appears. By means of the proved amorphous state, it seems possible to determine the amount of the amorphous state, which makes the drug more soluble from solid dispersions.
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Fahr F, Kala H, Diallo B, Metzner J. [The enhancement of solubility of problem drugs. 5. Solubility of griseofulvin-methylcellulose-PEG coprecipitates]. Pharmazie 1985; 40:362-3. [PMID: 4034644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Metzner J, Fahr F, Kala H, Hesse J, Diallo B. [The enhancement of solubility of problem drugs. 6. Antimycotic effectiveness of various griseofulvin preparations on Trichophyton mentagrophytes]. Pharmazie 1985; 40:363-4. [PMID: 4034645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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27
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Fahr F, Kala H, Masthoff F. [Improvement of the dissolution behavior of problem drugs. 4. Differential thermal analysis of iomeglamic acid-succinic acid embedding]. Pharmazie 1985; 40:270-1. [PMID: 4011664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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28
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Fahr F, Kala H, Pollandt P. [Improvement of the dissolution behavior of problem drugs. 3. X-ray diffraction measurement of iomeglamic acid/succinic acid solid dispersions]. Pharmazie 1985; 40:127-8. [PMID: 4001148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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29
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Fahr F, Kala H, Scharrenweber F. [The improvement of solubility behavior of problem drugs. 2. Solubility behavior of slow dissolving products of iomeglamic acid and succinic acid]. Pharmazie 1985; 40:60-1. [PMID: 3991791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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