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Wennman M, Pinon AC, Svagan AJ, Hellberg M, Hedenqvist MS. A biobased binder of carboxymethyl cellulose, citric acid, chitosan and wheat gluten for nonwoven and paper. Carbohydr Polym 2024; 323:121430. [PMID: 37940257 DOI: 10.1016/j.carbpol.2023.121430] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 09/18/2023] [Accepted: 09/22/2023] [Indexed: 11/10/2023]
Abstract
The amount of disposable nonwovens used today for different purposes have an impact on the plastic waste streams which is built up from several single-use products. A particular problem comes from nonwoven products with "hidden" plastic (such as cellulose mixed with synthetic fibers and/or plastic binders) where the consumers cannot see or expect plastic. We have here developed a sustainable binder based on natural components; wheat gluten (WG) and a polyelectrolyte complex (PEC) made from chitosan, carboxymethyl cellulose and citric acid which can be used with cellulosic fibers, creating a fully biobased nonwoven product. The binder formed a stable dispersion that improved the mechanical properties of a model nonwoven. With WG added, both the dry and the wet strength of the impregnated nonwoven increased. In dry-state, PEC increased the tensile index with >30 % (from 22.5 to 30 Nm/g), and with WG, with 60 % (to 36 Nm/g). The corresponding increase in the wet strength was 250 % (from 8 to 28 Nm/g) and 300 % (to 32 Nm/g). The increased strength was explained as an enrichment of covalent bonds (ester and amide bonds) established during curing at 170 °C, confirmed by DNP NMR and infrared spectroscopy.
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Affiliation(s)
- Maria Wennman
- OrganoClick AB, Linjalvägen 9, SE-187 66 Täby, Sweden.
| | - Arthur C Pinon
- Swedish NMR Center, University of Gothenburg, Gothenburg, Sweden
| | - Anna J Svagan
- KTH Royal Institute of Technology, School of Engineering Sciences of Chemistry, Biotechnology and Health, Fibre and Polymer Technology, SE-100 44 Stockholm, Sweden
| | | | - Mikael S Hedenqvist
- KTH Royal Institute of Technology, School of Engineering Sciences of Chemistry, Biotechnology and Health, Fibre and Polymer Technology, SE-100 44 Stockholm, Sweden.
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2
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Gong J, Wang T, Zhang W, Han L, Gao M, Chen T, Shen T, Ji Y. Organo-Vermiculites Modified by Aza-Containing Gemini Surfactants: Efficient Uptake of 2-Naphthol and Bromophenol Blue. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:3636. [PMID: 36296825 PMCID: PMC9609671 DOI: 10.3390/nano12203636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/10/2022] [Accepted: 10/13/2022] [Indexed: 06/16/2023]
Abstract
To explore the effect of spacer structure on the adsorption capability of organo-vermiculites (organo-Vts), a series of aza-containing gemini surfactants (5N, 7N and 8N) are applied to modify Na-vermiculite (Na-Vt). Large interlayer spacing, strong binding strength and high modifier availability are observed in organo-Vts, which endow them with superiority for the adsorption of 2-naphthol (2-NP) and bromophenol blue (BPB). The maximum adsorption capacities of 5N-Vt, 7N-Vt and 8N-Vt toward 2-NP/BPB are 142.08/364.49, 156.61/372.65 and 146.50/287.90 mg/g, respectively, with the adsorption processes well fit by the PSO model and Freundlich isotherm. The quicker adsorption equilibrium of 2-NP than BPB is due to the easier diffusion of smaller 2-NP molecules into the interlayer space of organo-Vts. Moreover, stable regeneration of 7N-Vt is verified, with feasibility in the binary-component system that is demonstrated. A combination of theoretical simulation and characterization is conducted to reveal the adsorption mechanism; the adsorption processes are mainly through partition processes, electrostatic interaction and functional interactions, in which the spacer structure affects the interlayer environment and adsorptive site distribution, whereas the adsorbate structure plays a role in the diffusion process and secondary intermolecular interactions. The results of this study demonstrate the versatile applicability of aza-based organo-Vts targeted at the removal of phenols and dyes as well as provide theoretical guidance for the structural optimization and mechanistic exploration of organo-Vt adsorbents.
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Affiliation(s)
- Jianchao Gong
- Hoffmann Institute of Advanced Materials, Shenzhen Polytechnic, 7098 Liuxian Boulevard, Nanshan District, Shenzhen 518055, China
| | - Tingting Wang
- Hoffmann Institute of Advanced Materials, Shenzhen Polytechnic, 7098 Liuxian Boulevard, Nanshan District, Shenzhen 518055, China
- Innovation Laboratory of Materials for Energy and Environment Technologies, Department of Physics, College of Science, Tibet University, Lhasa 850000, China
| | - Wei Zhang
- PetroChina Petrochemical Research Institute, Beijing 102206, China
| | - Lin Han
- Hoffmann Institute of Advanced Materials, Shenzhen Polytechnic, 7098 Liuxian Boulevard, Nanshan District, Shenzhen 518055, China
- Innovation Laboratory of Materials for Energy and Environment Technologies, Department of Physics, College of Science, Tibet University, Lhasa 850000, China
| | - Mingxiao Gao
- Anshan No. 1 Middle School, Anshan 114051, China
| | - Tianen Chen
- Hoffmann Institute of Advanced Materials, Shenzhen Polytechnic, 7098 Liuxian Boulevard, Nanshan District, Shenzhen 518055, China
| | - Tao Shen
- Hoffmann Institute of Advanced Materials, Shenzhen Polytechnic, 7098 Liuxian Boulevard, Nanshan District, Shenzhen 518055, China
| | - Yaxiong Ji
- Hoffmann Institute of Advanced Materials, Shenzhen Polytechnic, 7098 Liuxian Boulevard, Nanshan District, Shenzhen 518055, China
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Veselý L, Susrisweta B, Heger D. Making good's buffers good for freezing: The acidity changes and their elimination via mixing with sodium phosphate. Int J Pharm 2021; 593:120128. [PMID: 33271311 DOI: 10.1016/j.ijpharm.2020.120128] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 11/23/2020] [Accepted: 11/25/2020] [Indexed: 10/22/2022]
Abstract
Solutions of three Good's buffers (HEPES, MOPS, and MES), both pure and mixed with sodium phosphate buffers (Na-P), are investigated in terms of the freezing-induced acidity changes in their operational pH ranges. The Good's buffers have the tendency to basify upon freezing and, more intensively, at lower pHs. The acidity varies most prominently in MES, where the change may reach the value of two. Importantly, the Good's buffers are shown to mitigate the strong acidification in the Na-P buffer. Diverse concentrations of the Good's buffers are added to cancel out the strong, freezing-induced acidity drop in 50 mM Na-P that markedly contributes to the solution's acidity; the relevant values are 3 mM HEPES, 10 mM MOPS, and 80 mM MES. These buffer blends are therefore proposed to be applied in maintaining approximately the acidity of solutions even after the freezing process and, as such, should limit the stresses for frozen chemicals and biochemicals.
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Affiliation(s)
- Lukáš Veselý
- Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Behera Susrisweta
- Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Dominik Heger
- Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic.
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Altaani BM, Alkhamis KA, Abu Baker S, Haddad R. The relationship between the Hammett acidity and the decomposition of cefotaxime sodium in the solid state. Drug Dev Ind Pharm 2020; 46:1632-1638. [DOI: 10.1080/03639045.2020.1813754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Bashar M. Altaani
- Department of Pharmaceutical Technology, Jordan University of Science and Technology, Irbid, Jordan
| | - Khouloud A. Alkhamis
- Department of Pharmaceutical Technology, Jordan University of Science and Technology, Irbid, Jordan
| | - Shaima’a Abu Baker
- Department of Pharmaceutical Technology, Jordan University of Science and Technology, Irbid, Jordan
| | - Razan Haddad
- Department of Pharmaceutical Technology, Jordan University of Science and Technology, Irbid, Jordan
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Imrichová K, Veselý L, Gasser TM, Loerting T, Neděla V, Heger D. Vitrification and increase of basicity in between ice Ihcrystals in rapidly frozen dilute NaCl aqueous solutions. J Chem Phys 2019; 151:014503. [DOI: 10.1063/1.5100852] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Affiliation(s)
- Kamila Imrichová
- Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic
- Institute of Scientific Instruments of the ASCR, v.v.i., Královopolská 147, 61264 Brno, Czech Republic
| | - Lukáš Veselý
- Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic
| | - Tobias M. Gasser
- Institute of Physical Chemistry, University of Innsbruck, A-6020 Innsbruck, Austria
| | - Thomas Loerting
- Institute of Physical Chemistry, University of Innsbruck, A-6020 Innsbruck, Austria
| | - Vilém Neděla
- Institute of Scientific Instruments of the ASCR, v.v.i., Královopolská 147, 61264 Brno, Czech Republic
| | - Dominik Heger
- Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic
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Ueda H, Wu W, Löbmann K, Grohganz H, Müllertz A, Rades T. Application of a Salt Coformer in a Co-Amorphous Drug System Dramatically Enhances the Glass Transition Temperature: A Case Study of the Ternary System Carbamazepine, Citric Acid, and l-Arginine. Mol Pharm 2018; 15:2036-2044. [DOI: 10.1021/acs.molpharmaceut.8b00174] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hiroshi Ueda
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
- Research Laboratory for Development, Shionogi & Co., Ltd., Osaka 541-0045, Japan
| | - Wenqi Wu
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Korbinian Löbmann
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Holger Grohganz
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Anette Müllertz
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Thomas Rades
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
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7
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Comparing the acidities of aqueous, frozen, and freeze-dried phosphate buffers: Is there a “pH memory” effect? Int J Pharm 2017; 530:316-325. [DOI: 10.1016/j.ijpharm.2017.08.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Revised: 07/25/2017] [Accepted: 08/01/2017] [Indexed: 11/20/2022]
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8
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Forney-Stevens KM, Bogner RH, Pikal MJ. Addition of Amino Acids to Further Stabilize Lyophilized Sucrose-Based Protein Formulations: I. Screening of 15 Amino Acids in Two Model Proteins. J Pharm Sci 2016; 105:697-704. [DOI: 10.1002/jps.24655] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Revised: 08/20/2015] [Accepted: 08/26/2015] [Indexed: 02/05/2023]
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9
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Stabilization of proteins in solid form. Adv Drug Deliv Rev 2015; 93:14-24. [PMID: 25982818 DOI: 10.1016/j.addr.2015.05.006] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 05/07/2015] [Accepted: 05/09/2015] [Indexed: 12/15/2022]
Abstract
Immunogenicity of aggregated or otherwise degraded protein delivered from depots or other biopharmaceutical products is an increasing concern, and the ability to deliver stable, active protein is of central importance. We review characterization approaches for solid protein dosage forms with respect to metrics that are intended to be predictive of protein stability against aggregation and other degradation processes. Each of these approaches is ultimately motivated by hypothetical connections between protein stability and the material property being measured. We critically evaluate correlations between these properties and stability outcomes, and use these evaluations to revise the currently standing hypotheses. Based on this we provide simple physical principles that are necessary (and possibly sufficient) for generating solid delivery vehicles with stable protein loads. Essentially, proteins should be strongly coupled (typically through H-bonds) to the bulk regions of a phase-homogeneous matrix with suppressed β relaxation. We also provide a framework for reliable characterization of solid protein forms with respect to stability.
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10
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Dette HP, Koop T. Glass Formation Processes in Mixed Inorganic/Organic Aerosol Particles. J Phys Chem A 2014; 119:4552-61. [DOI: 10.1021/jp5106967] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Hans P. Dette
- Faculty of Chemistry and
Center for Molecular Materials, Bielefeld University, Universitätsstraße
25, D-33615 Bielefeld, Germany
| | - Thomas Koop
- Faculty of Chemistry and
Center for Molecular Materials, Bielefeld University, Universitätsstraße
25, D-33615 Bielefeld, Germany
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11
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Kim KM, Choi MH, Lee JK, Jeong J, Kim YR, Kim MK, Paek SM, Oh JM. Physicochemical properties of surface charge-modified ZnO nanoparticles with different particle sizes. Int J Nanomedicine 2014; 9 Suppl 2:41-56. [PMID: 25565825 PMCID: PMC4279853 DOI: 10.2147/ijn.s57923] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
In this study, four types of standardized ZnO nanoparticles were prepared for assessment of their potential biological risk. Powder-phased ZnO nanoparticles with different particle sizes (20 nm and 100 nm) were coated with citrate or L-serine to induce a negative or positive surface charge, respectively. The four types of coated ZnO nanoparticles were subjected to physicochemical evaluation according to the guidelines published by the Organisation for Economic Cooperation and Development. All four samples had a well crystallized Wurtzite phase, with particle sizes of ∼30 nm and ∼70 nm after coating with organic molecules. The coating agents were determined to have attached to the ZnO surfaces through either electrostatic interaction or partial coordination bonding. Electrokinetic measurements showed that the surface charges of the ZnO nanoparticles were successfully modified to be negative (about −40 mV) or positive (about +25 mV). Although all the four types of ZnO nanoparticles showed some agglomeration when suspended in water according to dynamic light scattering analysis, they had clearly distinguishable particle size and surface charge parameters and well defined physicochemical properties.
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Affiliation(s)
- Kyoung-Min Kim
- Department of Chemistry and Medical Chemistry, College of Science and Technology, Yonsei University, Gangwon-do, South Korea
| | - Mun-Hyoung Choi
- Department of Chemistry, Kyungpook National University, Taegu, South Korea
| | - Jong-Kwon Lee
- Toxicological Research Division, National Institute of Food and Drug Safety Evaluation, Chungchungbuk-do, South Korea
| | - Jayoung Jeong
- Toxicological Research Division, National Institute of Food and Drug Safety Evaluation, Chungchungbuk-do, South Korea
| | - Yu-Ri Kim
- Department of Biochemistry and Molecular Biology, Korea University Medical School and College, Seoul, South Korea
| | - Meyoung-Kon Kim
- Department of Biochemistry and Molecular Biology, Korea University Medical School and College, Seoul, South Korea
| | - Seung-Min Paek
- Department of Chemistry, Kyungpook National University, Taegu, South Korea
| | - Jae-Min Oh
- Department of Chemistry and Medical Chemistry, College of Science and Technology, Yonsei University, Gangwon-do, South Korea
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12
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Hill JJ, Shalaev EY, Zografi G. The importance of individual protein molecule dynamics in developing and assessing solid state protein preparations. J Pharm Sci 2014; 103:2605-2614. [PMID: 24867196 DOI: 10.1002/jps.24021] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 05/05/2014] [Accepted: 05/06/2014] [Indexed: 11/09/2022]
Abstract
Processing protein solutions into the solid state is a common approach for generating stable amorphous protein mixtures that are suitable for long-term storage. Great care is typically given to protecting the protein native structure during the various drying steps that render it into the amorphous solid state. However, many studies illustrate that chemical and physical degradations still occur in spite of this amorphous material having good glassy properties and it being stored at temperatures below its glass transition temperature (Tg). Because of these persistent issues and recent biophysical studies that have refined the debate ascribing meaning to the molecular dynamical transition temperature and Tg of protein molecules, we provide an updated discussion on the impact of assessing and managing localized, individual protein molecule nondiffusive motions in the context of proteins being prepared into bulk amorphous mixtures. Our aim is to bridge the pharmaceutical studies addressing bulk amorphous preparations and their glassy behavior, with the biophysical studies historically focused on the nondiffusive internal protein dynamics and a protein's activity, along with their combined efforts in assessing the impact of solvent hydrogen-bonding networks on local stability. We also provide recommendations for future research efforts in solid-state formulation approaches.
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Affiliation(s)
- John J Hill
- Department of Bioengineering, University of Washington, Seattle, WA 98195.
| | | | - George Zografi
- School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin 53705-2222
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Ohtake S, Shalaev E. Effect of Water on the Chemical Stability of Amorphous Pharmaceuticals: I. Small Molecules. J Pharm Sci 2013; 102:1139-54. [DOI: 10.1002/jps.23440] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 10/10/2012] [Accepted: 12/11/2012] [Indexed: 11/07/2022]
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14
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Gana FZ, Rashid I, Badwan A, Alkhamis KA. Determination of solid-state acidity of chitin-metal silicates and their effect on the degradation of cephalosporin antibiotics. J Pharm Sci 2012; 101:2398-407. [PMID: 22499263 DOI: 10.1002/jps.23142] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 03/06/2012] [Accepted: 03/16/2012] [Indexed: 11/11/2022]
Abstract
It was of interest to determine the solid-state acidity of chitin-metal silicate coprocessed excipients and to correlate this acidity to the chemical stability of cefotaxime sodium in the presence of the aforementioned excipients. The solid-state acidities of chitin aluminum silicate, chitin magnesium silicate, and chitin calcium silicate were determined by reflectance spectroscopy using structurally different dye molecules. The chemical stability of cefotaxime sodium was assessed at 50 °C in a 4% (w/v) slurry system in the pH range 6.6-10.5 and in the solid-state in the Hammett acidity range 6.1-7.8. The solid-state acidity was found to be reproducible because one or more structurally different dye molecules gave reliable solid-state acidity values. A significant discrepancy in pH stability profile of cefotaxime sodium between the solid-state and the slurry system was observed. Furthermore, chitin aluminum silicate showed minimum drug stability in the solid-state, close to where the maximum drug stability in the slurry was observed. This unexpected effect might be ascribed to the catalytic properties of chitin aluminum silicate. The slurry method was not able to predict efficiently the solid-state surface acidity and stability of cefotaxime sodium. Moreover, the solid-state chemical stability might be influenced by factors other than the solid-state acidity.
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Affiliation(s)
- Fatima Zohra Gana
- Faculty of Pharmacy, Jordan University of Science and Technology, Irbid 22110, Jordan
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15
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Ferreira J, Brolo AG, Girotto E. Probing speciation inside a conducting polymer matrix by in situ spectroelectrochemistry. Electrochim Acta 2011. [DOI: 10.1016/j.electacta.2011.01.076] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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16
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Barakat NS, Almurshedi AS. Design and development of gliclazide-loaded chitosan microparticles for oral sustained drug delivery: in-vitro/in-vivo evaluation. J Pharm Pharmacol 2011; 63:169-78. [DOI: 10.1111/j.2042-7158.2010.01214.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Abstract
Objectives
The objective of this study was to prepare gliclazide–chitosan microparticles with tripolyphosphate by ionic crosslinking.
Methods
Chitosan microparticles were produced by emulsification and ionotropic gelation. The effects of process variables including chitosan concentration, pH of tripolyphosphate solution, glutaraldehyde volume and release modifier agent such as pectin added to the tripolyphosphate crosslinking solution were evaluated. The microparticles were examined with scanning electron microscopy, infrared spectroscopy and differential scanning colorimetry. The serum glucose lowering effect of gliclazide microparticles was studied in streptozotocin-diabetic rabbits compared with the effect of pure gliclazide powder and gliclazide commercial tablets.
Key findings
The particle sizes of tripolyphosphate–chitosan microparticles were over the range 675–887 µm and the loading efficiency of drug was greater than 94.0%. In-vivo testing of the gliclazide–chitosan microparticles in diabetic rabbits demonstrated a significant antidiabetic effect of gliclazide–chitosan microparticles after 8 h that lasted for 18 h compared with gliclazide powder, which produced a maximum hypoglycaemic effect after 4 h.
Conclusions
The results suggests that gliclazide–chitosan microparticles are a valuable system for the sustained delivery of gliclazide.
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Affiliation(s)
- Nahla S Barakat
- Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Alanood S Almurshedi
- Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
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Barakat NS, Almurshedi AS. Design and development of gliclazide-loaded chitosan for oral sustained drug delivery:In vitro/in vivoevaluation. J Microencapsul 2010; 28:122-33. [DOI: 10.3109/02652048.2010.535621] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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18
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Barakat NS, Almurshedi AS. Preparation and characterization of chitosan microparticles for oral sustained delivery of gliclazide: in vitro/in vivo evaluation. Drug Dev Res 2010. [DOI: 10.1002/ddr.20389] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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19
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Hailu SA, Bogner RH. Solid-State Surface Acidity and pH-Stability Profiles of Amorphous Quinapril Hydrochloride and Silicate Formulations. J Pharm Sci 2010; 99:2786-99. [DOI: 10.1002/jps.22051] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Alkhamis KA. Influence of Solid-State Acidity on the Decomposition of Sucrose in Amorphous Systems II (Effect of Buffer). Drug Dev Ind Pharm 2009; 35:408-16. [DOI: 10.1080/03639040802422096] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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21
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Izutsu KI, Kadoya S, Yomota C, Kawanishi T, Yonemochi E, Terada K. Stabilization of Protein Structure in Freeze-Dried Amorphous Organic Acid Buffer Salts. Chem Pharm Bull (Tokyo) 2009; 57:1231-6. [DOI: 10.1248/cpb.57.1231] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
| | - Saori Kadoya
- Faculty of Pharmaceutical Sciences, Toho University
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Izutsu KI, Kadoya S, Yomota C, Kawanishi T, Yonemochi E, Terada K. Freeze-Drying of Proteins in Glass Solids Formed by Basic Amino Acids and Dicarboxylic Acids. Chem Pharm Bull (Tokyo) 2009; 57:43-8. [DOI: 10.1248/cpb.57.43] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
| | - Saori Kadoya
- Faculty of Pharmaceutical Sciences, Toho University
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Influence of solid-state acidity on the decomposition of sucrose in amorphous systems. I. Int J Pharm 2008; 362:74-80. [PMID: 18647642 DOI: 10.1016/j.ijpharm.2008.06.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2008] [Revised: 05/09/2008] [Accepted: 06/16/2008] [Indexed: 11/21/2022]
Abstract
It was of interest to develop a method for solid-state acidity measurements using pH indicators and to correlate this method to the degradation rate of sucrose. Amorphous samples containing lactose 100mg/ml, sucrose 10mg/ml, citrate buffer (1-50mM) and sodium chloride (to adjust the ionic strength) were prepared by freeze-drying. The lyophiles were characterized using powder X-ray diffraction, differential scanning calorimetry and Karl Fischer titremetry. The solid-state acidity of all lyophiles was measured using diffuse reflectance spectroscopy and suitable indicators (thymol blue or bromophenol blue). The prepared lyophiles were subjected to a temperature of 60 degrees C and were analyzed for degradation using the Trinder kit. The results obtained from this study have shown that the solid-state acidity depends mainly on the molar ratio of the salt and the acid used in buffer preparation and not on the initial pH of the solution. The degradation of sucrose in the lyophiles is extremely sensitive to the solid-state acidity and the ionic strength. Reasonable correlation was obtained between the Hammett acidity function and sucrose degradation rate. The use of cosolvents (in the calibration plots) can provide good correlations with the rate of an acid-catalyzed reaction, sucrose inversion, in amorphous lyophiles.
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Chatterjee K, Shalaev EY, Suryanarayanan R, Govindarajan R. Correlation between chemical reactivity and the Hammett acidity function in amorphous solids using inversion of sucrose as a model reaction. J Pharm Sci 2008; 97:274-86. [PMID: 17828730 DOI: 10.1002/jps.21081] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The goal was to evaluate the effects of acidity, expressed as the Hammett acidity function, on chemical reactivity in freeze-dried materials (lyophiles). Dextran-sucrose-citrate and polyvinyl pyrrolidone (PVP)-sucrose-citrate aqueous solutions, adjusted to pH values of 2.6, 2.8, and 3.0 were freeze dried, and characterized by X-ray powder diffractometry, DSC, isothermal microcalorimetry, and Karl Fischer titrimetry. Lyophiles were also prepared from identical solutions but containing bromophenol blue (BB). Diffuse reflectance-visible spectroscopy was used to measure the extent of BB protonation from which the Hammett acidity functions were determined. The stability studies were performed at 60 degrees C. All the freeze-dried samples were observed to be X-ray amorphous with <0.15% w/w water content. The T(g) of dextran lyophiles were approximately 20 degrees C higher than that of PVP lyophiles whereas enthalpy relaxation rates at 60 degrees C were similar. The Hammett acidity functions were significantly lower (i.e., higher acidity) for dextran systems (<2.2-2.6) when compared with PVP systems (3.3-3.9). The rate of sucrose inversion was significantly (an order of magnitude) higher in dextran lyophiles. This study showed that in amorphous matrices with comparable water content and structural relaxation times, chemical reactivity could be significantly different depending on the matrix "acidity".
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Affiliation(s)
- Koustuv Chatterjee
- College of Pharmacy, 308, Harvard St. S.E., University of Minnesota, Minneapolis, MN 55455, USA
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25
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Chen S, Liu M, Jin S, Wang B. Preparation of ionic-crosslinked chitosan-based gel beads and effect of reaction conditions on drug release behaviors. Int J Pharm 2007; 349:180-7. [PMID: 17900834 DOI: 10.1016/j.ijpharm.2007.08.029] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2007] [Revised: 06/04/2007] [Accepted: 08/11/2007] [Indexed: 10/22/2022]
Abstract
Drug-loaded chitosan (CS) beads were prepared under simple and mild condition using trisodium citrate as ionic crosslinker. The beads were further coated with poly(methacrylic acid) (PMAA) by dipping the beads in PMAA aqueous solution. The surface and cross-section morphology of these beads were observed by scanning electron microscopy and the observation showed that the coating beads had core-shell structure. In vitro release of model drug from these beads obtained under different reaction conditions was investigated in buffer medium (pH 1.8). The results showed that the rapid drug release was restrained by PMAA coating and the optimum conditions for preparing CS-based drug-loaded beads were decided through the effect of reaction conditions on the drug release behaviors. In addition, the drug release mechanism of CS-based drug-loaded beads was analyzed by Peppa's potential equation. According to this study, the ionic-crosslinked CS beads coated by PMAA could serve as suitable candidate for drug site-specific carrier in stomach.
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Affiliation(s)
- Shilan Chen
- Department of Chemistry and State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, PR China
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26
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Schaefer J, Jiang H, Ransome AE, Kappock TJ. Multiple active site histidine protonation states in Acetobacter aceti N5-carboxyaminoimidazole ribonucleotide mutase detected by REDOR NMR. Biochemistry 2007; 46:9507-12. [PMID: 17655332 PMCID: PMC2793534 DOI: 10.1021/bi700899q] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Class I PurE (N5-carboxyaminoimidazole mutase) catalyzes a chemically unique mutase reaction. A working mechanistic hypothesis involves a histidine (His45 in Escherichia coli PurE) functioning as a general acid, but no evidence for multiple protonation states has been obtained. Solution NMR is a peerless tool for this task but has had limited application to enzymes, most of which are larger than its effective molecular size limit. Solid-state NMR is not subject to this limit. REDOR NMR studies of a 151 kDa complex of uniformly 15N-labeled Acetobacter aceti PurE (AaPurE) and the active site ligand [6-13C]citrate probed a single ionization equilibrium associated with the key histidine (AaPurE His59). In the AaPurE complex, the citrate central carboxylate C6 13C peak moves upfield, indicating diminution of negative charge, and broadens, indicating heterogeneity. Histidine 15N chemical shifts indicate His59 exists in approximately equimolar amounts of an Ndelta-unprotonated (pyridine-like) form and an Ndelta-protonated (pyrrole-like) form, each of which is approximately 4 A from citrate C6. The spectroscopic data are consistent with proton transfers involving His59 Ndelta that are invoked in the class I PurE mechanism.
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Affiliation(s)
- Jacob Schaefer
- Department of Chemistry, Washington University in St. Louis, St. Louis MO 63130-4899
| | - Hong Jiang
- Department of Chemistry, Washington University in St. Louis, St. Louis MO 63130-4899
| | - Aaron E. Ransome
- Department of Chemistry, Washington University in St. Louis, St. Louis MO 63130-4899
| | - T. Joseph Kappock
- Department of Chemistry, Washington University in St. Louis, St. Louis MO 63130-4899
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27
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Nuthakki B, Greaves TL, Krodkiewska I, Weerawardena A, Burgar MI, Mulder RJ, Drummond CJ. Protic Ionic Liquids and Ionicity. Aust J Chem 2007. [DOI: 10.1071/ch06363] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Protic ionic liquids (PILs) are a subset of ionic liquids formed by the equimolar mixing of a Brønsted acid and a Brønsted base. PILs have been categorized as poor ionic liquids. However, the issue of assessing the ionicity of PILs is still a matter of debate. In this work we studied some physicochemical properties of three chosen PILs, namely, ethanolammonium acetate (EOAA), 2-methylbutylammonium formate (2MBAF), and pentylammonium formate (PeAF), at the initial equimolar (stoichiometric) acid/base ratio and in the presence of excess acid and base. DSC phase-transition studies along with NMR, IR, and Raman spectroscopy were performed on the chosen PILs. The results are discussed in terms of the degree of ionization (extent of proton transfer from the Brønsted acid to Brønsted base), and the possibility of the formation of polar 1:1 complexes and larger aggregates in the neat stoichiometric PILs.
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28
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Houchin M, Neuenswander S, Topp E. Effect of excipients on PLGA film degradation and the stability of an incorporated peptide. J Control Release 2006; 117:413-20. [PMID: 17207882 PMCID: PMC1864950 DOI: 10.1016/j.jconrel.2006.11.023] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2006] [Revised: 11/22/2006] [Accepted: 11/27/2006] [Indexed: 11/24/2022]
Abstract
The effect of pH modifying excipients on the chemical stability of a model peptide (VYPNGA) and the degradation of poly(dl-lactide-co-glycolide)(PLGA) was studied in PLGA films under accelerated storage conditions. pH modifiers included a basic amine (proton sponge), a basic salt (magnesium hydroxide) and two pH buffers (ammonium acetate and magnesium acetate). Changes in film pH were monitored using (13)C NMR, peptide degradation products were quantified by LC/MS/MS and PLGA degradation was analyzed by TGA, DSC and SEC. Inclusion of pH modifiers had little impact on PLGA degradation. The proton sponge affected an initial decrease in pH but reduced peptide deamidation and chain cleavage relative to an unbuffered control. Magnesium hydroxide produced an initial increase in pH but also showed increased peptide deamidation. Ammonium acetate decreased pH and increased peptide chain cleavage, presumably due to increased PLGA hydrolysis. Magnesium acetate buffer increased the initial pH but resulted in increased peptide loss. The extent of peptide acylation increased in all formulations, most notably in the proton sponge modified films. The effectiveness of pH modifiers in PLGA formulations under storage conditions is dependant on both the mechanism of pH alteration and the peptide degradation reaction of interest.
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Affiliation(s)
- M.L. Houchin
- Department of Pharmaceutical Chemistry, The University of Kansas, Lawrence, KS
| | | | - E.M. Topp
- Department of Pharmaceutical Chemistry, The University of Kansas, Lawrence, KS
- *To whom correspondence should be addressed: Department of Pharmaceutical Chemistry, The University of Kansas, 2095 Constant Ave. Lawrence, KS 66047, Phone: 785-864-4820, e-mail:
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29
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Govindarajan R, Chatterjee K, Gatlin L, Suryanarayanan R, Shalaev EY. Impact of Freeze-Drying on Ionization of Sulfonephthalein Probe Molecules in Trehalose–Citrate Systems. J Pharm Sci 2006; 95:1498-510. [PMID: 16721795 DOI: 10.1002/jps.20620] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
"pH memory," i.e., correlation between pH of solution before freeze-drying and chemical reactivity in the freeze-dried state, has been reported in many systems. In this study, the "pH memory" is explored by comparing the extent of protonation of sulfonephthalein probe molecules, bromophenol blue, bromocresol green, and chlorophenol red, in aqueous solution in the pH range of 3.4-6.0 and in the resulting freeze-dried amorphous matrix (lyophile) containing trehalose and sodium citrate buffer. The protonation of the probe molecules was measured in the lyophiles by diffuse reflectance visible spectroscopy, and compared with that in the solution before drying. The protonation of the indicators in the amorphous matrix correlated with solution pH, that is, an increase in solution pH resulted in a progressive decrease in the indicator protonation in the corresponding lyophile. However, the protonation was consistently higher in the lyophile than in the corresponding solution. The Hammett acidity function of lyophiles was calculated based on the extent of protonation of the probe molecules. Protonation of the probe molecules and the Hammett acidity function depended not only on prelyophilization solution pH, but also on the residual water content and the presence of amorphous sugar in the lyophile.
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Affiliation(s)
- Ramprakash Govindarajan
- Department of Pharmaceutics, University of Minnesota, 308 Harvard St. SE, Minneapolis, 55455, USA
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30
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Hill JJ, Shalaev EY, Zografi G. Thermodynamic and dynamic factors involved in the stability of native protein structure in amorphous solids in relation to levels of hydration. J Pharm Sci 2005; 94:1636-67. [PMID: 15965985 DOI: 10.1002/jps.20333] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The internal, dynamical fluctuations of protein molecules exhibit many of the features typical of polymeric and bulk small molecule glass forming systems. The response of a protein's internal molecular mobility to temperature changes is similar to that of other amorphous systems, in that different types of motions freeze out at different temperatures, suggesting they exhibit the alpha-beta-modes of motion typical of polymeric glass formers. These modes of motion are attributed to the dynamic regimes that afford proteins the flexibility for function but that also develop into the large-scale collective motions that lead to unfolding. The protein dynamical transition, T(d), which has the same meaning as the T(g) value of other amorphous systems, is attributed to the temperature where protein activity is lost and the unfolding process is inhibited. This review describes how modulation of T(d) by hydration and lyoprotectants can determine the stability of protein molecules that have been processed as bulk, amorphous materials. It also examines the thermodynamic, dynamic, and molecular factors involved in stabilizing folded proteins, and the effects typical pharmaceutical processes can have on native protein structure in going from the solution state to the solid state.
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Affiliation(s)
- John J Hill
- ICOS Corporation, 22021 20th Avenue SE, Bothell, WA 98021, USA.
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31
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Li B, Gorman EM, Moore KD, Williams T, Schowen RL, Topp EM, Borchardt RT. Effects of acidic N + 1 residues on asparagine deamidation rates in solution and in the solid state. J Pharm Sci 2005; 94:666-75. [PMID: 15668945 DOI: 10.1002/jps.20263] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The deamidation kinetics of four model peptides (AcGQNGG, AcGQNDG, AcGQNEG, and AcGQNQG) were studied in solution (70 degrees C, pH 5-10) and in lyophilized solids [70 degrees C, 50% relative humidity, "effective pH" ('pH') 5-10] containing polyvinyl pyrrolidone. AcGQNGG, AcGQNEG, and AcGQNQG degraded exclusively through Asn deamidation, whereas AcGQNDG also displayed Asp isomerization, and Asp-Gly peptide bond cleavage. The pH/'pH'-rate profiles were consistent with a shift in the rate-determining step of Asn deamidation from carbonyl addition to expulsion of ammonia with increasing pH. In solution, AcGQNGG deamidated up to 38-fold faster than the other peptides, indicating the importance of steric effects of the N + 1 residue. AcGQNGG and AcGQNQG had up to 60 times slower rates of deamidation in the solid state than in solution. In contrast, the deamidation rates of AcGQNEG and AcGQNDG in the solid state were similar to those in solution. N + 1 Glu or Asp residue may enhance local hydration, so that the deamidation of Asn in the solid formulations actually proceeds in a solution-like environment.
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Affiliation(s)
- Bei Li
- Department of Pharmaceutical Chemistry, The University of Kansas, 2095 Constant Avenue, Lawrence, Kansas 66047, USA
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