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Matsumoto A, Watanabe C, Murakami M. Janus microspheres for enhanced enteral drug delivery: Preparation and orientated attachment to a Caco-2 monolayer. Drug Discov Ther 2020; 13:343-353. [PMID: 31956233 DOI: 10.5582/ddt.2019.01090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Conventional oral preparations generally release incorporated drugs omnidirectionally, including into the lumen, leading to a low bioavailability of drugs that are unstable in the gastrointestinal tract. Here, we designed Janus microspheres for efficient mucosal drug delivery as single-sided-release microspheres with the oriented attachment to mucus and evaluated their attachment to and orientation on a Caco-2 (human Caucasian colon adenocarcinoma cell line) monolayer. The microspheres comprised a mucus-oriented hemisphere of an ammonioalkyl methacrylate copolymer and a protective hemisphere of a hard fat. Fluorescein isothiocyanate-dextran with an average molecular weight of 3,000-5,000 Da (FD4) was used as a model hydrophilic drug. A water-in-oil emulsion-type solvent evaporation method was employed for fabrication of the Janus microspheres. The yield of Janus microspheres was found to be dependent on the polymer-to-hard fat ratio, with a maximum yield of over 90% being obtained at a ratio of 1:2, whereas lower and higher ratios resulted in monolithic or star-shaped microspheres. FD4 was specifically localized in the polymeric hemisphere. A cell culture study revealed that the Janus microspheres attached to a Caco-2 monolayer via their polymeric hemispheres with the hard fat hemisphere providing a protective sealing. This may lead to the development of an effective enteral drug delivery system for biomedicines, such as polypeptides and nucleic acids.
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Affiliation(s)
- Akihiro Matsumoto
- Laboratory of Pharmaceutics, Faculty of Pharmacy, Osaka Ohtani University, Tondabayashi, Osaka, Japan
| | - Chie Watanabe
- Laboratory of Pharmaceutics, Faculty of Pharmacy, Osaka Ohtani University, Tondabayashi, Osaka, Japan.,Laboratory of Clinical Pathology, Faculty of Pharmacy, Josai University, Sakadoshi, Saitama, Japan
| | - Masahiro Murakami
- Laboratory of Pharmaceutics, Faculty of Pharmacy, Osaka Ohtani University, Tondabayashi, Osaka, Japan
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2
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Rongthong T, Sungthongjeen S, Siepmann F, Siepmann J, Pongjanyakul T. Eudragit RL-based film coatings: How to minimize sticking and adjust drug release using MAS. Eur J Pharm Biopharm 2020; 148:126-133. [PMID: 31982576 DOI: 10.1016/j.ejpb.2020.01.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/14/2020] [Accepted: 01/20/2020] [Indexed: 11/26/2022]
Abstract
Polymeric film coatings based on quaternary polymethacrylates (QPMs, e.g. Eudragits®) are frequently used for controlled release applications. However, their considerable sticking tendency is a major drawback in practice. In this study, different amounts of magnesium aluminum silicate (MAS) were added to the film coatings in order to overcome this hurdle. MAS is negatively charged and can electrostatically interact with the positively charged QPM. Different types of tablet cores were coated with aqueous Eudragit® RL 30D dispersions, optionally containing varying amounts of MAS. Dynamic changes in the wet mass of the systems as well as drug release upon exposure to 0.1 M HCl and phosphate buffer pH 6.8 were monitored. Propranolol HCl, acetaminophen, and diclofenac sodium were used as cationic, nonionic and anionic model drugs. The tablets were optionally cured for 12 h at 45 or 60 °C. Importantly, the addition of MAS to aqueous Eudragit® RL 30D dispersion substantially reduced the films' stickiness and led to stable inner coating structures, even without curing. Desired drug release rates can be adjusted by varying the QPM:MAS ratio and coating level.
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Affiliation(s)
- Thitiphorn Rongthong
- Division of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Srisagul Sungthongjeen
- Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Naresuan University, Phitsanulok 65000, Thailand
| | | | | | - Thaned Pongjanyakul
- Division of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand; Biomaterials for Pharmaceutical Formulation and Drug Delivery, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand.
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3
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Pruessmann K, Wentzlaff M, Schilling R, Seidlitz A. Influence of Dissolution Vessel Geometry and Dissolution Medium on In Vitro Dissolution Behaviour of Triamterene-Coated Model Stents in Different Test Setups. AAPS PharmSciTech 2019; 20:27. [PMID: 30604074 DOI: 10.1208/s12249-018-1227-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 10/21/2018] [Indexed: 11/30/2022] Open
Abstract
The aim of this study was to investigate if the geometry of the dissolution vessel, the dissolution medium volume and composition might contribute to the variation in drug release from drug-eluting stents (DES) in different test setups, which has been observed in previous in vitro studies. Therefore, DES containing triamterene as model substance were produced via fluidised-bed technology. Dissolution testing was carried out using different incubation setups, the reciprocating holder (USP Apparatus 7) and two flow-through methods, a method similar to the USP Apparatus 4 (FTC) and the vessel-simulating flow-through cell (vFTC) equipped with a hydrogel as a second compartment simulating the blood vessel wall. The results indicate that dissolution vessel geometry and medium volume had no influence on the release behaviour and only the flow-through cell methods yielded a lower dissolution rate than the incubation setups (80.6 ± 2.0% released in the FTC after 14 days compared to > 90% for all incubation setups). The composition of the hydrogel used in the vFTC also affected the dissolution rate (53.9 ± 4.5% within 14 days with a hydrogel based on phosphate-buffered saline compared to 78.2 ± 1.2% obtained with a hydrogel based on water) possibly due to different solubility of triamterene in the release media as well as interactions between the coating polymer and the release medium. Hence, the introduction of a hydrogel as a second compartment might lead to a more biorelevant test setup.
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Karkossa F, Klein S. Individualized in vitro and in silico methods for predicting in vivo performance of enteric-coated tablets containing a narrow therapeutic index drug. Eur J Pharm Biopharm 2018; 135:13-24. [PMID: 30529296 DOI: 10.1016/j.ejpb.2018.12.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 10/23/2018] [Accepted: 12/04/2018] [Indexed: 12/26/2022]
Abstract
The efficacy of narrow therapeutic index (NTI) drugs is closely related to their plasma concentration-time profile. Particularly for these compounds interindividual variability of gastrointestinal (GI) parameters relevant to in vivo drug release may result in fluctuations of the plasma concentration. The present study focused on assessing the influence of individual GI pH- and transit profiles on drug release of enteric valproate tablet formulations by means of individualized in vitro dissolution experiments. After initial experiments simulating GI passages in average healthy adults, a novel in vitro dissolution model was used to simulate individual GI pH- and transit profiles with physiologically relevant dissolution media. Based on the dissolution profiles obtained in these experiments, individual in silico plasma profiles were generated and compared to fasted in vivo data applying a mean Euclidean distance approach. Simulated individual gastric residence time was identified as crucial parameter determining the onset of absorption, whereas the shape of the plasma profile is mainly influenced by individual valproate pharmacokinetics. The novel in vitro and in silico methods used in this study are promising tools for estimating in vivo drug release and plasma concentration in individual subjects and thus may contribute to a prospective risk assessment for NTI formulations.
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Affiliation(s)
- Frank Karkossa
- University of Greifswald, Department of Pharmacy, Institute of Biopharmaceutics and Pharmaceutical Technology, Center of Drug Absorption and Transport (C_DAT), Felix-Hausdorff-Straße 3, 17489 Greifswald, Germany
| | - Sandra Klein
- University of Greifswald, Department of Pharmacy, Institute of Biopharmaceutics and Pharmaceutical Technology, Center of Drug Absorption and Transport (C_DAT), Felix-Hausdorff-Straße 3, 17489 Greifswald, Germany.
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Karkossa F, Klein S. Assessing the influence of media composition and ionic strength on drug release from commercial immediate-release and enteric-coated aspirin tablets. J Pharm Pharmacol 2017; 69:1327-1340. [DOI: 10.1111/jphp.12777] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 05/28/2017] [Indexed: 12/01/2022]
Abstract
Abstract
Objectives
The objective of this test series was to elucidate the importance of selecting the right media composition for a biopredictive in-vitro dissolution screening of enteric-coated dosage forms.
Methods
Drug release from immediate-release (IR) and enteric-coated (EC) aspirin formulations was assessed in phosphate-based and bicarbonate-based media with different pH, electrolyte composition and ionic strength.
Key findings
Drug release from aspirin IR tablets was unaffected by media composition. In contrast, drug release from EC aspirin formulations was affected by buffer species and ionic strength. In all media, drug release increased with increasing ionic strength, but in bicarbonate-based buffers was delayed when compared with that in phosphate-based buffers. Interestingly, the cation species in the dissolution medium had also a clear impact on drug release. Drug release profiles obtained in Blank CarbSIF, a new medium simulating pH and average ionic composition of small intestinal fluid, were different from those obtained in all other buffer compositions studied.
Conclusions
Results from this study in which the impact of various media parameters on drug release of EC aspirin formulations was systematically screened clearly show that when developing predictive dissolution tests, it is important to simulate the ionic composition of intraluminal fluids as closely as possible.
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Affiliation(s)
- Frank Karkossa
- Department of Pharmacy, Institute of Biopharmaceutics and Pharmaceutical Technology, Center of Drug Absorption and Transport (C_DAT), University of Greifswald, Greifswald, Germany
| | - Sandra Klein
- Department of Pharmacy, Institute of Biopharmaceutics and Pharmaceutical Technology, Center of Drug Absorption and Transport (C_DAT), University of Greifswald, Greifswald, Germany
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6
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Wulff R, Leopold CS. Coatings of Eudragit® RL and L-55 Blends: Investigations on the Drug Release Mechanism. AAPS PharmSciTech 2016; 17:493-503. [PMID: 26265188 DOI: 10.1208/s12249-015-0377-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2015] [Accepted: 07/21/2015] [Indexed: 11/30/2022] Open
Abstract
In a previous study, generally lower drug release rates from RL:L55 blend coated pellets in neutral/basic release media than in acidic release media were reported. The aim of this study was to obtain information on the drug release mechanism of solid dosage forms coated with blends of Eudragit® RL (RL) and Eudragit® L-55 (L55). Swelling experiments with free films were analyzed spectroscopically and gravimetrically to identify the physicochemical cause for this release behavior. With Raman spectroscopy, the swelling of copolymer films could be monitored. IR spectroscopic investigations on RL:L55 blends immersed in media at pH 6.8 confirmed the formation of interpolyelectrolyte complexes (IPECs) that were not detectable after swelling in hydrochloric acid pH 1.2. Further investigations revealed that these IPECs decreased the extent of ion exchange between the quaternary ammonium groups of RL and the swelling media. This is presumably the reason for the previously reported decreased drug permeability of RL:L55 coatings in neutral/basic media as ion exchange is the determining factor in drug release from RL coated dosage forms. Gravimetric erosion studies confirmed that L55 was not leached out of the film blends during swelling in phosphate buffer pH 6.8. In contrast to all other investigated films, the 4:1 (RL:L55) blend showed an extensive swelling within 24 h at pH 6.8 which explains the reported sigmoidal release behavior of 4:1 blend coated pellets. These results help to understand the release behavior of RL:L55 blend coated solid dosage forms.
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Shibata H, Yoshida H, Izutsu KI, Goda Y. Use of bicarbonate buffer systems for dissolution characterization of enteric-coated proton pump inhibitor tablets. ACTA ACUST UNITED AC 2016; 68:467-74. [PMID: 27019275 DOI: 10.1111/jphp.12540] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 01/30/2016] [Indexed: 12/25/2022]
Abstract
OBJECTIVES The aim of this study was to assess the effects of buffer systems (bicarbonate or phosphate at different concentrations) on the in vitro dissolution profiles of commercially available enteric-coated tablets. METHODS In vitro dissolution tests were conducted using an USP apparatus II on 12 enteric-coated omeprazole and rabeprazole tablets, including innovator and generic formulations in phosphate buffers, bicarbonate buffers and a media modified Hanks (mHanks) buffer. KEY FINDINGS Both omeprazole and rabeprazole tablets showed similar dissolution profiles among products in the compendial phosphate buffer system. However, there were large differences between products in dissolution lag time in mHanks buffer and bicarbonate buffers. All formulations showed longer dissolution lag times at lower concentrations of bicarbonate or phosphate buffers. The dissolution rank order of each formulation differed between mHanks buffer and bicarbonate buffers. A rabeprazole formulation coated with a methacrylic acid copolymer showed the shortest lag time in the high concentration bicarbonate buffer, suggesting varied responses depending on the coating layer and buffer components. CONCLUSION Use of multiple dissolution media during in vitro testing, including high concentration bicarbonate buffer, would contribute to the efficient design of enteric-coated drug formulations.
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Affiliation(s)
- Hiroko Shibata
- National Institute of Health Sciences, Setagaya-ku, Tokyo, Japan
| | - Hiroyuki Yoshida
- National Institute of Health Sciences, Setagaya-ku, Tokyo, Japan
| | - Ken-Ichi Izutsu
- National Institute of Health Sciences, Setagaya-ku, Tokyo, Japan
| | - Yukihiro Goda
- National Institute of Health Sciences, Setagaya-ku, Tokyo, Japan
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Silva JM, Caridade SG, Costa RR, Alves NM, Groth T, Picart C, Reis RL, Mano JF. pH Responsiveness of Multilayered Films and Membranes Made of Polysaccharides. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:11318-28. [PMID: 26421873 PMCID: PMC5015704 DOI: 10.1021/acs.langmuir.5b02478] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
We investigated the pH-dependent properties of multilayered films made of chitosan (CHI) and alginate (ALG) and focused on their postassembly response to different pH environments using a quartz crystal microbalance with dissipation monitoring (QCM-D), swelling studies, ζ potential measurements, and dynamic mechanical analysis (DMA). In an acidic environment, the multilayers presented lower dissipation values and, consequently, higher moduli when compared with the values obtained for the pH used during the assembly (5.5). When the multilayers were exposed to alkaline environments, the opposite behavior occurred. These results were further corroborated by the ability of this multilayered system to exhibit a reversible swelling-deswelling behavior within the pH range from 3 to 9. The changes in the physicochemical properties of the multilayer system were gradual and different from those of individual solubilized polyelectrolytes. This behavior is related to electrostatic interactions between the ionizable groups combined with hydrogen bonding and hydrophobic interactions. Beyond the pH range of 3-9, the multilayers were stabilized by genipin cross-linking. The multilayered films also became more rigid while the pH responsiveness conferred by the ionizable moieties of the polyelectrolytes was preserved. This work demonstrates the versatility and feasibility of LbL methodology to generate inherently pH stimulus-responsive nanostructured films. Surface functionalization using pH responsiveness endows several biomedical applications with abilities such as drug delivery, diagnostics, microfluidics, biosensing, and biomimetic implantable membranes.
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Affiliation(s)
- Joana M. Silva
- 3B’s Research Group – Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence of Tissue Engineering and Regenerative Medicine, Avepark – Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Barco GMR, Portugal
- ICVS/3B’s - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Sofia G. Caridade
- 3B’s Research Group – Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence of Tissue Engineering and Regenerative Medicine, Avepark – Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Barco GMR, Portugal
- ICVS/3B’s - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Rui R. Costa
- 3B’s Research Group – Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence of Tissue Engineering and Regenerative Medicine, Avepark – Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Barco GMR, Portugal
- ICVS/3B’s - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Natália M. Alves
- 3B’s Research Group – Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence of Tissue Engineering and Regenerative Medicine, Avepark – Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Barco GMR, Portugal
- ICVS/3B’s - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Thomas Groth
- Biomedical Materials Group, Martin Luther University Halle-Wittenberg, Heinrich-Damerow-Strasse 4, 06120 Halle (Saale), Saxony-Anhalt, Germany
| | - Catherine Picart
- CNRS, UMR 5628, LMGP, F-38016, Grenoble
- University Grenoble Alpes, Institut National Polytechnique de Grenoble, F-38016 Grenoble, France
| | - Rui L. Reis
- 3B’s Research Group – Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence of Tissue Engineering and Regenerative Medicine, Avepark – Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Barco GMR, Portugal
- ICVS/3B’s - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - João F. Mano
- 3B’s Research Group – Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence of Tissue Engineering and Regenerative Medicine, Avepark – Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Barco GMR, Portugal
- ICVS/3B’s - PT Government Associate Laboratory, Braga/Guimarães, Portugal
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9
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Wulff R, Rappen GM, Koziolek M, Garbacz G, Leopold C. Controlled release of acidic drugs in compendial and physiological hydrogen carbonate buffer from polymer blend-coated oral solid dosage forms. Eur J Pharm Sci 2015; 77:246-53. [DOI: 10.1016/j.ejps.2015.06.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 06/10/2015] [Accepted: 06/16/2015] [Indexed: 01/16/2023]
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10
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González-García I, Mangas-Sanjuán V, Merino-Sanjuán M, Bermejo M. In vitro–in vivocorrelations: general concepts, methodologies and regulatory applications. Drug Dev Ind Pharm 2015; 41:1935-47. [DOI: 10.3109/03639045.2015.1054833] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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11
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Wulff R, Leopold C. Coatings from blends of Eudragit® RL and L55: A novel approach in pH-controlled drug release. Int J Pharm 2014; 476:78-87. [DOI: 10.1016/j.ijpharm.2014.09.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 09/11/2014] [Accepted: 09/12/2014] [Indexed: 10/24/2022]
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12
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A dynamic system for the simulation of fasting luminal pH-gradients using hydrogen carbonate buffers for dissolution testing of ionisable compounds. Eur J Pharm Sci 2014; 51:224-31. [DOI: 10.1016/j.ejps.2013.09.020] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2013] [Revised: 09/04/2013] [Accepted: 09/21/2013] [Indexed: 11/20/2022]
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13
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Garbacz G, Kołodziej B, Koziolek M, Weitschies W, Klein S. An automated system for monitoring and regulating the pH of bicarbonate buffers. AAPS PharmSciTech 2013; 14:517-22. [PMID: 23468339 DOI: 10.1208/s12249-013-9933-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 02/04/2013] [Indexed: 11/30/2022] Open
Abstract
The bicarbonate buffer is considered as the most biorelevant buffer system for the simulation of intestinal conditions. However, its use in dissolution testing of solid oral dosage forms is very limited. The reason for this is the thermodynamic instability of the solution containing hydrogen carbonate ions and carbonic acid. The spontaneous loss of carbon dioxide (CO(2)) from the solution results in an uncontrolled increase of the pH. In order to maintain the pH on the desired level, either a CO(2) loss must be completely avoided or the escaped CO(2) has to be replaced by quantitative substitution, i.e. feeding the solution with the respective amount of gas, which re-acidifies the buffer after dissociation. The present work aimed at the development of a device enabling an automatic pH monitoring and regulation of hydrogen carbonate buffers during dissolution tests.
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14
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Lv W, Luo J, Deng Y, Sun Y. Biomaterials immobilized with chitosan for rechargeable antimicrobial drug delivery. J Biomed Mater Res A 2012; 101:447-55. [DOI: 10.1002/jbm.a.34350] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 06/26/2012] [Accepted: 06/27/2012] [Indexed: 11/10/2022]
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15
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Neuman RC, Gerig JT. Interactions of Nonprotic Organic Solvents with [Val5]angiotensin in Water. J Phys Chem B 2011; 115:1712-9. [DOI: 10.1021/jp1107125] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Robert C. Neuman
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - John T. Gerig
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
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16
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Neuman RC, Gerig JT. Interaction of Alcohols with [Val5]angiotensin in Alcohol−Water Mixtures. J Phys Chem B 2010; 114:6722-31. [DOI: 10.1021/jp101305u] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- R. C. Neuman
- Department of Chemistry & Biochemistry, University of California, Santa Barbara, California 93106
| | - J. T. Gerig
- Department of Chemistry & Biochemistry, University of California, Santa Barbara, California 93106
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17
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Adams WP, Ahrens RC, Chen ML, Christopher D, Chowdhury BA, Conner DP, Dalby R, Fitzgerald K, Hendeles L, Hickey AJ, Hochhaus G, Laube BL, Lucas P, Lee SL, Lyapustina S, Li B, O'Connor D, Parikh N, Parkins DA, Peri P, Pitcairn GR, Riebe M, Roy P, Shah T, Singh GJP, Sharp SS, Suman JD, Weda M, Woodcock J, Yu L. Demonstrating Bioequivalence of Locally Acting Orally Inhaled Drug Products (OIPs): Workshop Summary Report. J Aerosol Med Pulm Drug Deliv 2010; 23:1-29. [DOI: 10.1089/jamp.2009.0803] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Wallace P. Adams
- Food and Drug Administration, Center for Drug Evaluation and Research, Office of Pharmaceutical Science, Office of Generic Drugs, Rockville, Maryland
| | - Richard C. Ahrens
- University of Iowa Hospitals and Clinics, Department of Pediatrics, Iowa City, Iowa
| | - Mei-Ling Chen
- Food and Drug Administration, Center for Drug Evaluation and Research, Silver Spring, Maryland
| | | | - Badrul A. Chowdhury
- Food and Drug Administration, Center for Drug Evaluation and Research, Silver Spring, Maryland
| | - Dale P. Conner
- Food and Drug Administration, Center for Drug Evaluation and Research, Office of Pharmaceutical Science, Office of Generic Drugs, Rockville, Maryland
| | | | | | | | | | - Günther Hochhaus
- Department of Pharmaceutics, College of Pharmacy, University of Florida, Gainesville, Florida
| | - Beth L. Laube
- Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Paul Lucas
- Pfizer Global Research and Development, Sandwich, Kent, CT13 9NJ, United Kingdom
| | - Sau L. Lee
- Food and Drug Administration, Center for Drug Evaluation and Research, Office of Pharmaceutical Science, Office of Generic Drugs, Rockville, Maryland
| | | | - Bing Li
- Food and Drug Administration, Center for Drug Evaluation and Research, Office of Pharmaceutical Science, Office of Generic Drugs, Rockville, Maryland
| | - Dennis O'Connor
- Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut
| | | | | | - Prasad Peri
- Food and Drug Administration, Center for Drug Evaluation and Research, Silver Spring, Maryland
| | - Gary R. Pitcairn
- Pfizer Limited, Ramsgate Road, Sandwich, Kent, CT13 9NJ, United Kingdom
| | | | - Partha Roy
- Food and Drug Administration, Center for Drug Evaluation and Research, Silver Spring, Maryland
| | | | | | - Sandra Suarez Sharp
- Food and Drug Administration, Center for Drug Evaluation and Research, Silver Spring, Maryland
| | | | - Marjolein Weda
- National Institute for Public Health and the Environment (RIVM) Centre for Quality of Chemical-Pharmaceutical Products, Bilthoven, The Netherlands
| | - Janet Woodcock
- Food and Drug Administration, Center for Drug Evaluation and Research, Silver Spring, Maryland
| | - Lawrence Yu
- Food and Drug Administration, Center for Drug Evaluation and Research, Office of Pharmaceutical Science, Office of Generic Drugs, Rockville, Maryland
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18
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Gerig JT. Solvent Interactions with [Val5]angiotensin II in Ethanol−Water. J Phys Chem B 2008; 112:7967-76. [DOI: 10.1021/jp801489q] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- John T. Gerig
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106
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19
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Chatterjee C, Martinez D, Gerig JT. Interactions of Trifluoroethanol with [val5]angiotensin II. J Phys Chem B 2007; 111:9355-62. [PMID: 17630790 DOI: 10.1021/jp0711343] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Intermolecular 1H{19F} NOE experiments have been used to explore the interactions of trifluoroethanol (TFE) with the octapeptide hormone [val5]angiotensin II at temperatures from 5 to 25 degrees C. Circular dichroism spectra indicate that 40% trifluoroethanol has an influence on the conformations of the peptide, probably leading to beta-structures. Diffusion experiments show that the mean hydrodynamic radius of the peptide in 40% trifluoroethanol-water is about 8 A, consistent with significant folding of the peptide in this medium. Distance constraints derived from intramolecular NOESY data along with observed vicinal coupling constants (3JCalphaHNH) were used to develop conformations consistent with available data. Assuming that intermolecular 1H{19F} NOEs are the result of diffusive encounters of TFE and peptide molecules, it is shown that no single conformation is consistent with the experimental values of the sigmaHF cross-relaxation parameters. It is argued that the disagreements between observed and expected values of sigmaHF are the result of formation of long-lived (approximately 0.5 ns) fluoroalcohol-peptide complexes, a conclusion consonant with similar studies of other peptide-fluoroalcohol systems. Complex formation appears to be especially prevalent near the charged amino acid side chains of the hormone.
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Affiliation(s)
- Chiradip Chatterjee
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106, USA
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