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Simeonov M, Kostova B, Vassileva E. Interpenetrating Polymer Networks of Poly(2-hydroxyethyl methacrylate) and Poly(N, N-dimethylacrylamide) as Potential Systems for Dermal Delivery of Dexamethasone Phosphate. Pharmaceutics 2023; 15:2328. [PMID: 37765296 PMCID: PMC10538039 DOI: 10.3390/pharmaceutics15092328] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 09/10/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023] Open
Abstract
In this study, a series of novel poly(2-hydroxyethyl methacrylate) (PHEMA)/poly(N,N'-dimethylacrylamide) (PDMAM) interpenetrating polymer networks (IPNs) were synthesized and studied as potential drug delivery systems of dexamethasone sodium phosphate (DXP) for dermal application. The IPN composition allows for control over its swelling ability as the incorporation of the highly hydrophilic PDMAM increases more than twice the IPN swelling ratio as compared to the PHEMA single networks, namely from ~0.5 to ~1.1. The increased swelling ratio of the IPNs results in an increased entrapment efficiency up to ~30% as well as an increased drug loading capacity of DXP up to 4.5%. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) show the formation of a solid dispersion between the drug DXP and the polymer (IPNs) matrix. Energy-dispersive X-ray (EDX) spectroscopy shows an even distribution of DXP within the IPN structure. The DXP release follows Fickian diffusion with ~70% of DXP released in 24 h. This study demonstrates the potential of the newly developed IPNs for the dermal delivery of DXP.
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Affiliation(s)
- Marin Simeonov
- Laboratory on Structure and Properties of Polymers, Faculty of Chemistry and Pharmacy, University of Sofia, 1, J. Bourchier blvd., 1164 Sofia, Bulgaria;
| | - Bistra Kostova
- Department of Pharmaceutical Technology and Biopharmaceutics, Faculty of Pharmacy, Medical University of Sofia, 2, Dunav str., 1000 Sofia, Bulgaria
| | - Elena Vassileva
- Laboratory on Structure and Properties of Polymers, Faculty of Chemistry and Pharmacy, University of Sofia, 1, J. Bourchier blvd., 1164 Sofia, Bulgaria;
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2
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Bamford JT, Smith RA, Leng CZ, Gutekunst WR, Losego MD. Measuring the Glass Transition Temperature of Vapor-Phase-Infiltrated AlO x-PS- r-PHEMA Organic–Inorganic Hybrid Thin-Film Materials. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c00691] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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3
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Wirth DM, Jaquez A, Gandarilla S, Hochberg JD, Church DC, Pokorski JK. Highly Expandable Foam for Lithographic 3D Printing. ACS APPLIED MATERIALS & INTERFACES 2020; 12:19033-19043. [PMID: 32267677 DOI: 10.1021/acsami.0c02683] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In modern manufacturing, it is a widely accepted limitation that the parts patterned by an additive or subtractive manufacturing process (i.e., a lathe, mill, or 3D printer) must be smaller than the machine itself that produced them. Once such parts are manufactured, they can be postprocessed, fastened together, welded, or adhesively bonded to form larger structures. We have developed a foaming prepolymer resin for lithographic additive manufacturing, which can be expanded after printing to produce parts up to 40× larger than their original volume. This allows for the fabrication of structures significantly larger than the build volume of the 3D printer that produced them. Complex geometries comprised of porous foams have implications in technologically demanding fields such as architecture, aerospace, energy, and biomedicine. This manuscript presents a comprehensive screening process for resin formulations, detailed analysis of printing parameters, and observed mechanical properties of the 3D-printed foams.
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Affiliation(s)
- David M Wirth
- Department of NanoEngineering, University of California San Diego, Jacobs School of Engineering, La Jolla, California 92093, United States
| | - Anna Jaquez
- Department of NanoEngineering, University of California San Diego, Jacobs School of Engineering, La Jolla, California 92093, United States
| | - Sofia Gandarilla
- Department of NanoEngineering, University of California San Diego, Jacobs School of Engineering, La Jolla, California 92093, United States
| | - Justin D Hochberg
- Department of NanoEngineering, University of California San Diego, Jacobs School of Engineering, La Jolla, California 92093, United States
| | - Derek C Church
- Department of NanoEngineering, University of California San Diego, Jacobs School of Engineering, La Jolla, California 92093, United States
| | - Jonathan K Pokorski
- Department of NanoEngineering, University of California San Diego, Jacobs School of Engineering, La Jolla, California 92093, United States
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Jin Y, Aoki T, Kwak G. Control of Intramolecular Hydrogen Bonding in a Conformation‐Switchable Helical‐Spring Polymer by Solvent and Temperature. Angew Chem Int Ed Engl 2020; 59:1837-1844. [DOI: 10.1002/anie.201910269] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 10/29/2019] [Indexed: 01/26/2023]
Affiliation(s)
- Young‐Jae Jin
- Department of Polymer Science & EngineeringPolymeric Nanomaterials LaboratorySchool of Applied Chemical EngineeringKyungpook National University 1370 Sankyuk-dong, Buk-ku Daegu 702-701 Korea
| | - Toshiki Aoki
- Department of Chemistry and Chemical EngineeringGraduate School of Science and TechnologyCenter for Transdisciplinary ResearchNiigata University Ikarashi 2-8050, Nishi-ku Niigata 950-2181 Japan
| | - Giseop Kwak
- Department of Polymer Science & EngineeringPolymeric Nanomaterials LaboratorySchool of Applied Chemical EngineeringKyungpook National University 1370 Sankyuk-dong, Buk-ku Daegu 702-701 Korea
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5
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Control of Intramolecular Hydrogen Bonding in a Conformation‐Switchable Helical‐Spring Polymer by Solvent and Temperature. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201910269] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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6
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Pang J, Gao Z, Tan H, Mao X, Wang H, Hu X. Design, Synthesis, Investigation, and Application of a Macromolecule Photoswitch. Front Chem 2019; 7:86. [PMID: 30873401 PMCID: PMC6403147 DOI: 10.3389/fchem.2019.00086] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 01/31/2019] [Indexed: 11/18/2022] Open
Abstract
Azobenzene (AZO) has attracted increasing interest due to its reversible structural change upon a light stimulus. However, poor fatigue durability and the photobleaching phenomenon restricts its further application. Herein, the AZO domain as a pendent group, was incorporated into copolymers, which was synthesized by radical copolymerization in the research. Structure-properties of synthesized copolymer can be adjusted by monomer ratios. Emphatically, responsive properties of copolymer in different solutions were investigated. In the DMSO solution, copolymer exhibited effective structural change, stable rapid responsive time (1 min) upon UV light at room temperature, stable relative acceptable recovery time (100 min) upon white light at room temperature, and good fatigue resistance property. In an aqueous solution, even more controllable responsive properties and fatigue resistance properties for copolymer were verified by results. More pervasively, the recovery process could be controlled by light density and temperature. In order to clarify reasons for the difference between the AZO molecule and the AZO domain of copolymer, energy barrier or interactions between single atoms or even structural units was calculated using the density functional theory (DFT). Furthermore, the status of copolymer was characterized by dynamic light scattering (DLS) and transmission electron microscope (TEM). Finally, copolymer was further functionalized with bioactive protein (concanavalin, ConA) to reduce the cytotoxicity of the AZO molecule.
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Affiliation(s)
- Juan Pang
- School of Material Engineering, Jinling Institute of Technology, Nanjing, China
| | - Ziyu Gao
- School of Material Engineering, Jinling Institute of Technology, Nanjing, China
| | - Huaping Tan
- Biomaterials for Organogenesis Laboratory, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, China
| | - Xincheng Mao
- School of Material Engineering, Jinling Institute of Technology, Nanjing, China
| | - Huiming Wang
- School of Material Engineering, Jinling Institute of Technology, Nanjing, China
| | - Xiaohong Hu
- School of Material Engineering, Jinling Institute of Technology, Nanjing, China
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7
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The nature of nonfreezing water in carbohydrate polymers. Carbohydr Polym 2016; 150:353-8. [DOI: 10.1016/j.carbpol.2016.04.119] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 04/26/2016] [Accepted: 04/27/2016] [Indexed: 11/19/2022]
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8
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Morita S. Hydrogen-bonds structure in poly(2-hydroxyethyl methacrylate) studied by temperature-dependent infrared spectroscopy. Front Chem 2014; 2:10. [PMID: 24790979 PMCID: PMC3982535 DOI: 10.3389/fchem.2014.00010] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 02/24/2014] [Indexed: 11/22/2022] Open
Abstract
Hydrogen-bonds structure in poly(2-hydroxyethyl methacrylate) (PHEMA) were investigated by means of temperature-dependent infrared (IR) spectroscopy. Spectral variations involved with the OH…OH and C=O…HO types of hydrogen-bonds were found around the glass transition temperature of 80°C. Hydrogen-bonds among the hydroxyl groups gradually dissociate with increasing temperature. In contrast, discontinuous variation in the carbonyl bands was observed around the glass transition temperature. An association of the C=O…HO type of hydrogen-bond with increasing temperature above the glass transition temperature was revealed. These were concluded from the present study that hydrogen-bonds among the hydroxyl groups in each side chain terminal suppress the main chain mobility in the polymer matrix below the glass transition temperature, while the dissociation of the OH…OH type of hydrogen-bonds induces the association of the C=O…HO type of hydrogen-bond. As a result, the mobility of the main chain is induced by the change in hydrogen-bonds structure at the glass transition temperature.
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Affiliation(s)
- Shigeaki Morita
- Department of Engineering Science, Osaka Electro-Communication University Neyagawa, Japan
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Sun DD, Lee PI. Crosslinked hydrogels-a promising class of insoluble solid molecular dispersion carriers for enhancing the delivery of poorly soluble drugs. Acta Pharm Sin B 2014; 4:26-36. [PMID: 26579361 PMCID: PMC4590291 DOI: 10.1016/j.apsb.2013.12.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Revised: 12/17/2013] [Accepted: 12/18/2013] [Indexed: 01/15/2023] Open
Abstract
Water-insoluble materials containing amorphous solid dispersions (ASD) are an emerging category of drug carriers which can effectively improve dissolution kinetics and kinetic solubility of poorly soluble drugs. ASDs based on water-insoluble crosslinked hydrogels have unique features in contrast to those based on conventional water-soluble and water-insoluble carriers. For example, solid molecular dispersions of poorly soluble drugs in poly(2-hydroxyethyl methacrylate) (PHEMA) can maintain a high level of supersaturation over a prolonged period of time via a feedback-controlled diffusion mechanism thus avoiding the initial surge of supersaturation followed by a sharp decline in drug concentration typically encountered with ASDs based on water-soluble polymers. The creation of both immediate- and controlled-release ASD dosage forms is also achievable with the PHEMA based hydrogels. So far, ASD systems based on glassy PHEMA have been shown to be very effective in retarding precipitation of amorphous drugs in the solid state to achieve a robust physical stability. This review summarizes recent research efforts in investigating the potential of developing crosslinked PHEMA hydrogels as a promising alternative to conventional water-soluble ASD carriers, and a related finding that the rate of supersaturation generation does affect the kinetic solubility profiles implications to hydrogel based ASDs.
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Affiliation(s)
| | - Ping I. Lee
- Corresponding author. Tel.: +1 416 946 0606; fax: +1 416 978 8511.
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Dai M, Maxwell S, Vogt BD, La Belle JT. Mesoporous carbon amperometric glucose sensors using inexpensive, commercial methacrylate-based binders. Anal Chim Acta 2012; 738:27-34. [PMID: 22790696 DOI: 10.1016/j.aca.2012.05.038] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Revised: 05/16/2012] [Accepted: 05/21/2012] [Indexed: 10/28/2022]
Abstract
Two ordered, soft-templated mesoporous carbon powders with cubic and hexagonal framework structure and four different commercial, low cost methacrylate-based polymer binders with widely varying physical properties are investigated as screen printed electrodes for glucose sensors using glucose oxidase and ferricyanide as the mediator. Both the chemistry and concentration of the binder in the electrode formulation can significantly impact the performance. Poly(hydroxybutyl methacrylate) as the binder provides hydrophilicity to enable transport of species in the aqueous phase to the carbon surface, but yet is sufficiently hydrophobic to provide mechanical robustness to the sensor. The current from the mesoporous carbon electrodes can be more than an order of magnitude greater than for a commercial printed carbon electrode (Zensor) with improved sensitivity for model glucose solutions. Even when applying these sensors to rabbit whole blood, the performance of these glucose sensors compares favorably to a standard commercial glucose meter with the lower detection limit of the mesoporous electrode being approximately 20mgdL(-1) despite the lack of a separation membrane to prevent non-specific events; these results suggest that the small pore sizes and high surface areas associated with ordered mesoporous carbons may effectively decrease some non-specific inferences for electrochemical sensing.
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Affiliation(s)
- Mingzhi Dai
- School for Engineering of Matter, Transport and Energy, Arizona State University, 550 East Orange St., Tempe, AZ 85287-9709, United States.
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11
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Chirila TV, George KA, Abdul Ghafor WA, Pas SJ, Hill AJ. Sequential homo-interpenetrating polymer networks of poly(2-hydroxyethyl methacrylate): Synthesis, characterization, and calcium uptake. J Appl Polym Sci 2012. [DOI: 10.1002/app.36824] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Bastrop M, Meister A, Metz H, Drescher S, Dobner B, Mäder K, Blume A. Water Dynamics in Bolaamphiphile Hydrogels Investigated by 1H NMR Relaxometry and Diffusometry. J Phys Chem B 2010; 115:14-22. [DOI: 10.1021/jp107755k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Martin Bastrop
- Institute of Chemistry, Martin-Luther-University Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle/Saale, Germany, and Institute of Pharmacy, Martin-Luther-University Halle-Wittenberg, Wolfgang-Langenbeck-Str. 4, 06120 Halle/Saale,Germany
| | - Annette Meister
- Institute of Chemistry, Martin-Luther-University Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle/Saale, Germany, and Institute of Pharmacy, Martin-Luther-University Halle-Wittenberg, Wolfgang-Langenbeck-Str. 4, 06120 Halle/Saale,Germany
| | - Hendrik Metz
- Institute of Chemistry, Martin-Luther-University Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle/Saale, Germany, and Institute of Pharmacy, Martin-Luther-University Halle-Wittenberg, Wolfgang-Langenbeck-Str. 4, 06120 Halle/Saale,Germany
| | - Simon Drescher
- Institute of Chemistry, Martin-Luther-University Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle/Saale, Germany, and Institute of Pharmacy, Martin-Luther-University Halle-Wittenberg, Wolfgang-Langenbeck-Str. 4, 06120 Halle/Saale,Germany
| | - Bodo Dobner
- Institute of Chemistry, Martin-Luther-University Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle/Saale, Germany, and Institute of Pharmacy, Martin-Luther-University Halle-Wittenberg, Wolfgang-Langenbeck-Str. 4, 06120 Halle/Saale,Germany
| | - Karsten Mäder
- Institute of Chemistry, Martin-Luther-University Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle/Saale, Germany, and Institute of Pharmacy, Martin-Luther-University Halle-Wittenberg, Wolfgang-Langenbeck-Str. 4, 06120 Halle/Saale,Germany
| | - Alfred Blume
- Institute of Chemistry, Martin-Luther-University Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle/Saale, Germany, and Institute of Pharmacy, Martin-Luther-University Halle-Wittenberg, Wolfgang-Langenbeck-Str. 4, 06120 Halle/Saale,Germany
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Segale L, Giovannelli L, Pattarino F, Conti S, Maggi L, Grenier P, Vergnault G. Thermogravimetric investigation of the hydration behaviour of hydrophilic matrices. J Pharm Sci 2010; 99:2070-9. [PMID: 19780132 DOI: 10.1002/jps.21949] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
This article proposes thermogravimetric analysis (TGA) as a useful method to investigate the hydration behaviour of hydrophilic matrix tablets containing hydroxypropylmethylcellulose (HPMC), sodium carboxymethylcellulose (NaCMC) or a mixture of these two polymers and four drugs with different solubility. The hydration behaviour of matrix systems was studied as a function of the formulation composition and of the dissolution medium pH. TGA results suggest that the hydration of matrices containing HPMC is pH-independent and not affected by the characteristics of the loaded drug; this confirms HPMC as a good polymer to formulate controlled drug delivery systems. On the other hand, the performances of NaCMC matrix tablets are significantly affected by the medium pH and the hydration and swelling of this ionic polymer is influenced by the loaded drug. For systems containing the two polymers, HPMC plays a dominant role in the hydration/dissolution process at acidic pH, while at near neutral pH both the cellulose derivatives exert a significant influence on the hydration performance of systems. The results of this work show that TGA is able to give quantitative highlights on the hydration behaviour of polymeric materials; thus this technique could be a helpful tool to support conventional hydration/swelling/dissolution studies.
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Affiliation(s)
- Lorena Segale
- DISCAFF, Università degli Studi del Piemonte Orientale, Largo Donegani 2, 28100 Novara, Italy
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14
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Varma-Nair M, Costello CA, Colle KS, King HE. Thermal analysis of polymer–water interactions and their relation to gas hydrate inhibition. J Appl Polym Sci 2006. [DOI: 10.1002/app.25414] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Maldonado-Codina C, Efron N. An Investigation of the Discrete and Continuum Models of Water Behavior in Hydrogel Contact Lenses. Eye Contact Lens 2005; 31:270-8. [PMID: 16284507 DOI: 10.1097/01.icl.0000163432.74952.1a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To investigate the water behavior in hydrogels of differing equilibrium water content (EWC) and to use these results to investigate the opposing discrete model (thermodynamically different classes of water exist in hydrogels) and continuum model (water behaves as a consequence of nonequilibrium conditions) of nonfreezing water in swollen hydrogels. METHODS Differential scanning calorimetry (DSC) was used to obtain melting thermograms for five lenses of each of 12 hydrogel lens types. The gravimetric content of the nonfreezing water was subsequently determined from an integrated endotherm for water. The effect of anneal time on the amount of nonfreezing water obtained in samples was investigated before undertaking these measurements. The glass transition temperature (Tg) of each of the lens types was obtained with DSC to investigate how the Tg was related to the amount of nonfreezing water found in the hydrogels. RESULTS Melting enthalpy increased with increasing anneal time and leveled off at 6 hours. Low-EWC lenses showed endotherms with a single melting peak at 0 degrees C. Materials with a higher EWC showed more complicated melting endotherms, with a broad shoulder occurring at temperatures below 0 degrees C. There was a statistically significant positive correlation between EWC and freezing water (R=0.95, P<0.0001), but the amount of nonfreezing water was similar for all lens materials. There was a statistically significant positive correlation between the Tg of the hydrogels and the theoretically derived weight fraction of nonfreezing water in the hydrogels required to bring the Tg of the gels down to 0 degrees C (R=0.99, P<0.0001) but not with the experimentally derived values (R=0.29, P=0.07). CONCLUSIONS Low-EWC hydrogels have the lowest free-to-bound water ratios. That the experimentally derived values of nonfreezing water are different from the theoretically derived values creates doubt with the continuum model theory. The best model probably employs a combination of the discrete and continuum theories.
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Affiliation(s)
- Carole Maldonado-Codina
- Eurolens Research, Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom.
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16
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Megeed Z, Cappello J, Ghandehari H. Thermal Analysis of Water in Silk−Elastinlike Hydrogels by Differential Scanning Calorimetry. Biomacromolecules 2004; 5:793-7. [PMID: 15132663 DOI: 10.1021/bm0343491] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Zaki Megeed
- Department of Pharmaceutical Sciences and Greenebaum Cancer Center, University of Maryland, Baltimore, Maryland 21201, USA
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17
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Haigh R, Fullwood N, Rimmer S. Synthesis and properties of amphiphilic networks 2: a differential scanning calorimetric study of poly(dodecyl methacrylate-stat-2,3 propandiol-1-methacrylate-stat-ethandiol dimethacrylate) networks and adhesion and spreading of dermal fibroblasts on these materials. Biomaterials 2002; 23:3509-16. [PMID: 12099296 DOI: 10.1016/s0142-9612(02)00081-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A series of amphiphilic networks was prepared by radical copolymerisation of dodecyl methacrylate, 2,3-propandiol-1-methacrylate and ethandiol dimethacrylate. DSC studies on these materials, swollen in water. revealed that only materials containing more than 27 wt% of water displayed melting endotherms due to the melting of ice-like structures of water (freezing water). In materials that did produce a melting endotherm the peak was generally bimodal. Changing thermal history and heating rate did not effect the shape of the two peaks, nor the relative contribution of each peak to the total endothermic response. These observations and the narrow peak width of the low temperature endotherm suggested that the bimodality was an artefact of the DSC experiment and may be due to the promotion of the glass transition once a fraction of the water has frozen. The morphology of transformed human dermal fibroblasts grown on these materials was then examined by scanning electron microscopy. Compositions that contained only non-freezing water were found to allow cell adhesion and spreading. Cells with well-spread morphologies were obtained on materials containing small fractions of freezing water and dodecyl methacrylate. These fibroblasts displayed surface features such as microvilli and filapodia. However, all compositions of poly(2,3-propandiol-1-methacrylate-co-ethandiol dimethacrylate) (i.e. hydrogels that do not contain dodecyl methacrylate repeat units) were poor substrates for cell growth and examination of these materials showed that very few cells had adhered and those that did were highly rounded.
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Affiliation(s)
- R Haigh
- Department of Biological Sciences, University of Lancaster, UK
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18
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Katzhendler I, Mäder K, Friedman M. Structure and hydration properties of hydroxypropyl methylcellulose matrices containing naproxen and naproxen sodium. Int J Pharm 2000; 200:161-79. [PMID: 10867246 DOI: 10.1016/s0378-5173(00)00360-4] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The present study was conducted to obtain a deeper insight into the mechanism of drug release from HPMC matrices. The microstructure, mobility, internal pH and the state of water within the gel layer of hydrated HPMC matrices (having different molecular weights) containing naproxen sodium (NS) and naproxen (N) were studied using Electron Paramagnetic Resonance (EPR), Nuclear Magnetic Resonance (NMR) and Differential Scanning Calorimetry (DSC) techniques. The study show that matrices composed of various viscosity grades of HPMC are characterized by similar microviscosity values in spite of the difference in their molecular weight. The NMR and DSC results led to the conclusion that higher molecular weights of HPMC are characterized by higher water absorption capacity and higher swelling. Analysis of non-freezable water in HPMC(K4M)-NS system revealed that addition of NS to solution increased the fraction of water bound to K4M+NS compared with the equivalent solutions without NS. The results suggest that the drug is participating in the crystallization of water and leads to the formation of a three dimensional network structure that decreases the freedom of water in K4M+NS samples. Calculation of the number of hydration shells showed that up to 2.2 layers are involved in HPMC-NS hydration compared to 1.5 layers for HPMC gel without NS. This was explained based on the different water ordering in the gel induced by NS as results of its absorption to polymer surface. Microviscosity values measured by EPR for K4M/N and K4M/NS hydrated matrices were found to be higher for K4M/N matrices, especially at initial stage of hydration. Mobile compartment calculations showed lower values for K4M/N compared with K4M/NS matrices. pH measurements by EPR revealed that incorporation of N to HPMC matrix led to lower internal pH value inside the hydrated tablet compared with NS. This behavior led to lower solubility of N which dictates its surface erosion mechanism, compared with NS matrix that was characterized by higher internal pH value and higher drug solubility. These properties of HPMC/NS increased chain hydration and stability, and led to drug release by the diffusion mechanism.
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Affiliation(s)
- I Katzhendler
- Department of Pharmaceutics, School of Pharmacy, The Hebrew University of Jerusalem, PO Box 12065, 91120, Jerusalem, Israel
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Simon LD, Stella VJ, Charman WN, Charman SA. Variation in the diffusion and release of ribonuclease through and from esterified hyaluronic acid membranes: effect of changes in matrix characteristics. J Control Release 1999; 61:159-64. [PMID: 10469912 DOI: 10.1016/s0168-3659(99)00115-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
50 h) were detected for the transport and release of a model protein (ribonuclease A) compared with that for the translucent region which showed no lag time. The results highlight the importance of carefully controlling matrix formation to ensure reproducible transport and release characteristics from polymer matrices.
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Affiliation(s)
- L D Simon
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS 66045, USA
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Barbieri R, Quaglia M, Delfini M, Brosio E. Investigation of water dynamic behaviour in poly(HEMA) and poly(HEMA-co-DHPMA) hydrogels by proton T2 relaxation time and self-diffusion coefficient n.m.r. measurements. POLYMER 1998. [DOI: 10.1016/s0032-3861(97)00403-5] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Sun YM, Huang JJ, Lin FC, Lai JY. Composite poly(2-hydroxyethyl methacrylate) membranes as rate-controlling barriers for transdermal applications. Biomaterials 1997; 18:527-33. [PMID: 9105591 DOI: 10.1016/s0142-9612(96)00166-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Composite membranes were prepared by casting a linear poly(2-hydroxyethyl methacrylate) (pHEMA) solution onto polyester non-woven supports, and then the supported pHEMA within the membranes was cross-linked by a diisocyanate cross-linking agent to form a network structure. The swelling and permeation properties of these membranes were evaluated, with a system of nitroglycerin and aqueous ethanol solution, for potential application in transdermal drug delivery. The degree of swelling of these membranes in water and aqueous ethanol decreases as the cross-linker content is increased and increases slightly with an increase in the original molecular weight of the linear pHEMA. The permeation rates of both nitroglycerin and ethanol increase as the cross-linker content is reduced, the polymer molecular weight increases, and the concentration of the casting solution or membrane thickness decreases. Depending on the preparation conditions, the membranes can be tailored to give a permeation flux ranging from 4 to 68 micrograms cm-2 h-1 for nitroglycerin.
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Affiliation(s)
- Y M Sun
- Department of Chemical Engineering, Yuan-Ze Institute of Technology, Chung-Li, Taiwan, Republic of China
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22
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Solute transport in poly(2-hydroxyethyl methacrylate) hydrogel membranes. JOURNAL OF POLYMER RESEARCH 1995. [DOI: 10.1007/bf01493206] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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23
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Water behavior during drug release from a matrix as observed using differential scanning calorimetry. J Control Release 1995. [DOI: 10.1016/0168-3659(94)00108-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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24
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Effect of chloride on the release of chlorhexidine salts from methyl methacrylate: 2-hydroxyethyl methacrylate copolymer reservoir devices. J Control Release 1995. [DOI: 10.1016/0168-3659(94)00104-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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25
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Pyramides G, Robinson JW, Zito SW. The combined use of DSC and TGA for the thermal analysis of atenolol tablets. J Pharm Biomed Anal 1995; 13:103-10. [PMID: 7766716 DOI: 10.1016/0731-7085(94)00112-f] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The New York Regional Laboratory's forensic pharmaceutical group used thermal analysis (TA) to ensure adherence to batch formulations by drug manufacturers. TA in our laboratory consisted of differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). DSC and TGA were used to analyse finished dosage forms and their components. In this study the components of atenolol formulations were qualitatively identified by analysing individual components and comparing with the finished product. DSC and TGA were used together to develop a profile of batch formulations, with each analytical technique giving complementary types of information. For example, the excipient sodium starch glycolate was identified by DSC and confirmed by TGA. These experimental results demonstrated the use of TA for the characterization of finished dosage forms and the qualitative identification of some of the individual components in batch formulations.
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Affiliation(s)
- G Pyramides
- U.S. Department of Health & Human Services, Food and Drug Administration, Brooklyn, NY 11232, USA
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26
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Roorda W. Do hydrogels contain different classes of water? JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 1994. [DOI: 10.1163/156856294x00095] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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27
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Peschier LJ, Bouwstra JA, de Bleyser J, Junginger HE, Leyte JC. Water mobility and structure in poly[2-hydroxyethylmethacrylate] hydrogels by means of the pulsed field gradient NMR technique. Biomaterials 1993; 14:945-52. [PMID: 8268387 DOI: 10.1016/0142-9612(93)90137-q] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The translational mobility of water in poly[2-hydroxyethylmethacrylate] (pHEMA) hydrogels, cross-linked with ethyleneglycoldimethacrylate, was studied by means of the pulsed field gradient (PFG) nuclear magnetic resonance (NMR) technique, which offers the opportunity to study the molecular displacements directly under well-defined equilibrium conditions, resulting in a determination of the self-diffusion coefficient. It is possible to check whether coexisting water phases with different mobilities (on a timescale of ca. 10 ms) are present. The dependence of the diffusion coefficient of water on the degree of hydration and the cross-linker concentration was measured. Magnetic interaction is found to cause cross-relaxation between the protons of water and those of the polymer matrix. This affects the data, rendering the evaluation by the standard equation invalid. An equation taking cross-relaxation into account has been derived. Amplitude measurements have shown that all the water in the gels contributes to the NMR signal. The PFG measurements have shown that the total water phase in a gel diffuses as one homogeneous phase, which can be characterized by a diffusion coefficient. The self-diffusion coefficient is strongly dependent on the degree of hydration of the gel; the cross-linker concentration has no measurable effect. The strong dependence of the diffusion of water on its concentration in the gel has consequences for the modelling of the swelling and drug-release dynamics of pHEMA and necessitates a revision of the present models describing these processes.
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Affiliation(s)
- L J Peschier
- Centre for Bio-Pharmaceutical Sciences, University of Leiden, The Netherlands
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29
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Bae YH, Okano T, Kim SW. "On-off" thermocontrol of solute transport. I. Temperature dependence of swelling of N-isopropylacrylamide networks modified with hydrophobic components in water. Pharm Res 1991; 8:531-7. [PMID: 1871053 DOI: 10.1023/a:1015871732706] [Citation(s) in RCA: 143] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The swelling in water, as a function of temperature, of two series of N-isopropylacrylamide (NIPAAm) polymer networks was studied. In the first series, n-butylmethacrylate (BMA) was copolymerized with NIPAAm, and in the second, polytetramethylene ether glycol (PTMEG) was incorporated into NIPAAm network as a chemically independent interpenetrating network. With increasing BMA content in the poly(NIPAAm-co-BMA) network, the gel collapse point was lowered and the gels deswelled in a more gradual manner with increasing temperature. In the interpenetrating polymer networks (IPN) system, the gel collapse point was not significantly changed by the amount of incorporated PTMEG. In DSC thermograms of swollen samples, the shape and onset temperature of the endothermic peak corresponded to the gel deswelling behavior and gel collapse point. The temperature dependence of equilibrium swelling in water was shown to be a function of the gel composition in both network series. The synthesized networks formed a dense surface layer as the temperature increased past the gel collapse point. This dense layer retarded water efflux and thereby resulted in water pockets at the membrane surface.
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Affiliation(s)
- Y H Bae
- Department of Pharmaceutics, University of Utah, Salt Lake City 84112
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30
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Abstract
Nuclear magnetic relaxation was used to investigate the dynamic behaviour of water molecules in p(HEMA) gels. Results indicate that the rotational mobility of water in p(HEMA) gels is significantly reduced compared to that in pure water. The rotational mobility was mainly determined by total degree of swelling of the gels, and not by cross-linker content. No indications were found for the presence of dynamically different types of water in these gels on a timescale of milliseconds.
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Affiliation(s)
- W E Roorda
- Center for Bio-Pharmaceutical Sciences, University of Leiden, The Netherlands
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