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Chandrasekar V, Janes DW, Forrey C, Saylor DM, Bajaj A, Duncan TV, Zheng J, Riaz Ahmed KB, Casey BJ. Improving risk assessment of color additives in medical device polymers. J Biomed Mater Res B Appl Biomater 2017; 106:310-319. [PMID: 28140510 DOI: 10.1002/jbm.b.33845] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 12/09/2016] [Accepted: 12/19/2016] [Indexed: 11/08/2022]
Abstract
Many polymeric medical device materials contain color additives which could lead to adverse health effects. The potential health risk of color additives may be assessed by comparing the amount of color additive released over time to levels deemed to be safe based on available toxicity data. We propose a conservative model for exposure that requires only the diffusion coefficient of the additive in the polymer matrix, D, to be specified. The model is applied here using a model polymer (poly(ether-block-amide), PEBAX 2533) and color additive (quinizarin blue) system. Sorption experiments performed in an aqueous dispersion of quinizarin blue (QB) into neat PEBAX yielded a diffusivity D = 4.8 × 10-10 cm2 s-1 , and solubility S = 0.32 wt %. On the basis of these measurements, we validated the model by comparing predictions to the leaching profile of QB from a PEBAX matrix into physiologically representative media. Toxicity data are not available to estimate a safe level of exposure to QB, as a result, we used a Threshold of Toxicological Concern (TTC) value for QB of 90 µg/adult/day. Because only 30% of the QB is released in the first day of leaching for our film thickness and calculated D, we demonstrate that a device may contain significantly more color additive than the TTC value without giving rise to a toxicological concern. The findings suggest that an initial screening-level risk assessment of color additives and other potentially toxic compounds found in device polymers can be improved. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 310-319, 2018.
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Affiliation(s)
- Vaishnavi Chandrasekar
- Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland, 20993
| | | | - Christopher Forrey
- Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland, 20993
| | - David M Saylor
- Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland, 20993
| | - Akhil Bajaj
- Department of Food Science and Nutrition, Illinois Institute of Technology, Bedford Park, Illinois, 60501
| | - Timothy V Duncan
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, Bedford Park, Illinois, 60501
| | - Jiwen Zheng
- Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland, 20993
| | - Kausar B Riaz Ahmed
- Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland, 20993
| | - Brendan J Casey
- Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland, 20993
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Kopeček J. HYDROGELS FROM SOFT CONTACT LENSES AND IMPLANTS TO SELF-ASSEMBLED NANOMATERIALS. JOURNAL OF POLYMER SCIENCE. PART A, POLYMER CHEMISTRY 2009; 47:5929-5946. [PMID: 19918374 PMCID: PMC2776732 DOI: 10.1002/pola.23607] [Citation(s) in RCA: 287] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Hydrogels were the first biomaterials designed for clinical use. Their discovery and applications as soft contact lenses and implants are presented. This early hydrogel research served as a foundation for the expansion of biomedical polymers research into new directions: design of stimuli sensitive hydrogels that abruptly change their properties upon application of an external stimulus (pH, temperature, solvent, electrical field, biorecognition) and hydrogels as carriers for the delivery of drugs, peptides, and proteins. Finally, pathways to self-assembly of block and graft copolymers into hydrogels of precise 3D structures are introduced.
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Affiliation(s)
- Jindřich Kopeček
- Department of Bioengineering, Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, Utah 84112, USA
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Affiliation(s)
- R. LANGER
- a Department of Nutrition and Food Science , M.I.T. , Cambridge, Massachusetts, 02139,#253-3107
- b Department of Surgery , Children's Hospital Medical Center , Boston, Massachusetts, 02115, #734-6000x3508
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Dua RD, Vasudevan P, Kumar S. Carboxypeptidase Immobilization on a Cellulosic Matrix. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/00222338408065904] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Kulkarni PV, Rajur SB, Antich PP, Aminabhavi TM, Aralaguppi MI. TRANSPORT STUDIES ON MACROMOLECULES USED AS DRUG CARRIERS. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/07366579008050915] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Abd El-Rehima HA. Hemodialysis Membranes Based on Functionalized High-density Polyethylene. J BIOACT COMPAT POL 2005; 20:51-75. [DOI: 10.1177/0883911505049654] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
Grafting vinyl acetate (VAc) and maleic anhydride (MAn) comonomer onto high-density polyethylene (HDPE) was performed by means of gamma rays. Conditions for the minimum homopolymer formation, maximum grafting yield and alternate copolymer grafts were carried out. Further chemical treatment with sodium hydroxide, hydrochloric acid, ammonium hydroxide, sulfamic acid and amino pyridine were made on the grafted membranes to increase functionality. The swelling, mechanical, solute permeability and biocompatibility properties of these copolymers were evaluated for possible application as dialysis membranes. The introduction of functional groups on HDPE membranes enhanced their hydration and transport flux. The treated grafting membranes showed improved permeability towards urea, creatinine and uric acid over the ungrafted HDPE. The permeability rate of the solutes through the membranes depended on the molecular weight and the size of the solutes. The presence of hydrophilic groups on the membranes reduced protein adsorption and enhanced membrane transport. The swelling, solute dialysis permeability and protein low affinity properties of HDPE-g-(VAc-alt-MAn) treated with sulfamic acid or 2-aminopyridine indicate potential use as hemodialysis membranes.
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Affiliation(s)
- Hassan. A. Abd El-Rehima
- National Center for Radiation Research and Technology, Atomic Energy Authority, P.O. Box 29 Nasr City, Cairo, Egypt,
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Boyd BJ, Porter CJH, Charman WN. Using the polymer partitioning method to probe the thermodynamic activity of poorly water-soluble drugs solubilized in model lipid digestion products. J Pharm Sci 2003; 92:1262-71. [PMID: 12761815 DOI: 10.1002/jps.10390] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The thermodynamic activity of solubilized drug is an important determinant of the extent of absorption of lipophilic drugs from the gastrointestinal tract. In this study, the polymer partitioning method was evaluated for its use in the determination of the thermodynamic activity of lipophilic drugs when solubilized in colloidal digestion products, using drug in dilute solution as a reference ideal solution. The lipophilic drugs griseofulvin, diazepam, and danazol partitioned into a polymeric receiver phase from non-micellar solution as a function of drug lipophilicity. The concentration of drug that partitioned into the polymer was linearly proportional to the concentration of free drug in solution, and this allowed the measured partition coefficient to be utilized as an indicator of the drug activity coefficient. The addition of a solubilizing species such as bile salt micelles caused a reduction in drug activity of a similar magnitude to that predicted from micelle equilibrium solubility data in the identical micellar solutions. The addition of micelle swelling lipids such as lecithin and fatty acids resulted in further reductions in activity coefficient. The ability to measure drug activity in model digestive systems has potential for application in the rational development of improved lipid-based formulations of poorly water-soluble drugs for oral administration.
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Affiliation(s)
- Ben J Boyd
- Department of Pharmaceutics, Victorian College of Pharmacy, Monash University (Parkville Campus), 381 Royal Parade, Parkville, 3052, Australia
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Saad EA. Preparation, properties and selectivity characteristics of a novel cation exchanger prepared by γ-irradiation of phosphoenolpyruvic acid (PPA) and low-density polyethylene (LDPE). Microchem J 2001. [DOI: 10.1016/s0026-265x(01)00088-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Li T, Kildsig DO, Park K. Computer simulation of molecular diffusion in amorphous polymers. J Control Release 1997. [DOI: 10.1016/s0168-3659(97)00033-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Ravichandran P, Shantha K, Rao K. Preparation, swelling characteristics and evaluation of hydrogels for stomach specific drug delivery. Int J Pharm 1997. [DOI: 10.1016/s0378-5173(97)00131-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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El-Gibaly I, Safwat SM, Ahmed MO. Microencapsulation of ketoprofen using w/o/w complex emulsion technique. J Microencapsul 1996; 13:67-87. [PMID: 8903786 DOI: 10.3109/02652049609006804] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Sustained release cellulose acetate butyrate (CAB)-polystyrene (PS) microcapsules containing ketoprofen (a non-steroidal anti-inflammatory drug) were prepared adopting the modified W/O/W complex emulsion technique. The effect of polystyrene concentration and core/coat ratio on the yield, geometric mean particle diameter, dg, size distribution, drug loading as well as release and surface characteristics of the microcapsules was investigated. The results obtained revealed that polystyrene utilization as a wall material plays a dominant role in the manufacturing process. A particular composition of 92 center dot 5: 7 center dot 5 (%) of CAB to PS was found to improve greatly the microcapsule yield and maximize the drug loading. In most cases, the encapsulation efficiencies increased with increasing microcapsule size and theoretical drug loading. Kinetic analysis of the data shows that the drug release process from CAB microcapsules followed Higuchi model (a diffusion-controlled model for a planar matrix), whereas the release behaviour conforms with Baker and Lonsdale model (a diffusion-controlled model for a spherical matrix) for CAB-PS microcapsules. The preparation of free films of CAB and CAB-PS was described for comparison. The effect of processing parameters (polystyrene concentration, total polymers concentration and permeant concentration) on the permeation of ketoprofen through the polymeric films was discussed. The results demonstrated that ketoprofen permeation through the films and microcapsules could be controlled by modifying the CAB-PS ratio in the polymer matrices. The permeability constants lowered with increasing total polymers concentration up to 5% and were proportional to permeant concentration. To compare the kinetics of drug release from polymeric films with those of microcapsules, ketoprofen was incorporated at different concentrations within CAB-PS cast films. These films exhibited sustained release of the drug (t0 center dot 5; 58-146 h). Release rates were found to agree with the Baker and Lonsdale model, previously suggested for ketoprofen release from CAB-PS microcapsules.
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Affiliation(s)
- I El-Gibaly
- Pharmaceutics Department, Assiut University, Egypt
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Johnston T, Webb C, Schoen F, Levy R. Site-specific delivery of ethanehydroxy diphosphonate from refillable polyurethane reservoirs to inhibit bioprosthetic tissue calcification. J Control Release 1993. [DOI: 10.1016/0168-3659(93)90081-f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Pitt G, Cha Y, Shah S, Zhu K. Blends of PVA and PGLA: control of the permeability and degradability of hydrogels by blending. J Control Release 1992. [DOI: 10.1016/0168-3659(92)90076-4] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Affiliation(s)
- V V Ranade
- Action Medical Marketing Co., Libertyville, Illinois
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Roorda WE, Boddé HE, De Boer AG, Bouwstra JA, Junginer HE. Synthetic hydrogels as drug delivery systems. PHARMACEUTISCH WEEKBLAD. SCIENTIFIC EDITION 1986; 8:165-89. [PMID: 3526277 DOI: 10.1007/bf01959775] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Hydrogels are widely studied materials for the preparation of sustained release drug dosage forms. Their soft, tissue-like consistency and their high biocompatibility in a number of applications make them promising candidates for this purpose. The water and the polymer in the gel form intricate structures and much research has been devoted to the elucidation of these structures, and of the interactions involved in their formation. Simple, drug-loaded hydrogels normally give a matrix-type delivery profile, in which the release rate is proportional to the square root of time; a number of approaches has been used to change this profile to other types of delivery, for instance to zero-order release. A number of in vivo tests using hydrogel delivery systems has given favourable results.
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Vaginal pessaries from crystalline/rubbery hydrogels for the delivery of prostaglandin E2. J Control Release 1984. [DOI: 10.1016/0168-3659(84)90002-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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23
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Ahmed M, Hadgraft J, Kellaway I. Phenothiazine transport across liquid-lipid, phospholipid and soft polymer membranes. Int J Pharm 1983. [DOI: 10.1016/0378-5173(83)90009-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Sung YK, Gregonis DE, John MS, Andrade JD. Thermal and pulse NMR analysis of water in poly(2-hydroxyethyl methacrylate). J Appl Polym Sci 1981. [DOI: 10.1002/app.1981.070261118] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Matheson LE, Hunke WA. Mass transport properties of co(polyether)polyurethane membranes I: Preparation and characterization. J Pharm Sci 1981; 70:571-3. [PMID: 7241367 DOI: 10.1002/jps.2600700528] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
A series of polyurethane copolymers containing polyethylene glycol 600, 1000, or 1540 was synthesized, purified by reprecipitation, and cast into clear, tough, flexible membranes using the solution method. The weight average molecular weight of each polymer was estimated by gel permeation chromatography. The ability of the various polymers to absorb water was measured and increased with the increasing molecular weight of the polyethylene-glycol. The ability of the copolymer membranes to hold a pH gradient decreased with increasing polyethylene glycol molecular weight.
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Zentner GM, Cardinal JR, Feijen J, Song SZ. Progestin permeation through polymer membranes IV: Mechanism of steroid permeation and functional group contributions to diffusion through hydrogel films. J Pharm Sci 1979; 68:970-5. [PMID: 480176 DOI: 10.1002/jps.2600680814] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Hydrogel films were prepared from hydroxyethyl methacrylate, both with (Film II) and withouth (Film I) 5.25 mole% of ethylene glycol dimethacrylate. Permeation, diffusion, and partition coefficients for progesterone, testosterone, nandrolone, norethindrone, 17 alpha-hydroxyprogesterone, estradiol, and hydrocortisone were determined. A solute permeation model was proposed based on the separation of a domain (B) composed of "bulk-like" water and a doman (A) composed of polymer, interfacial water, and bound water present in the films. The separate contributions from the "pore" and "solution-diffusion" mechanisms to the total permeability were calculated from the model. Steroid permeabilities through Films I and II were analyzed in accordance with this model. Permeation of Film II occurred via the solution-diffusion mechanism. Permeation of Film I occurred predominately by the pore mechanism with a small contribution (approximate 20%) from the solution-diffusion mechanism. The latter contribution was dependent on the solubility of the solute within the A domains of the hydrogel film. Functional group contributions to permeation of Film II were ascribed to either steric or hydrogen bonding effects.
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Zentner GM, Cardinal JR, Gregonis DE. Progestin permeation through polymer membranes III: Polymerization solvent effect on progesterone permeation through hydrogel membranes. J Pharm Sci 1979; 68:794-5. [PMID: 458587 DOI: 10.1002/jps.2600680635] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Hydrogels prepared from poly(hydroxyethyl methacrylate) are biocompatible and highly permeable to low molecular weight solutes. Permeation rates can be varied by altering the cross-linker concentration or using copolymers; the latter are chosen to alter the hydrogel equilibrium hydration. These factors suggest that hydrogels are good candidates for controlled-release drug delivery devices. Hydrogels may be synthesized using various temperatures, initiators (nature and concentration), and solvents (nature and concentration). This study demonstrated that progesterone permeation through poly(hydroxyethyl methacrylate) films is independent of polymerization solvent (nature and concentration) for the solvents, water, ethanol, and tert-butyl alcohol. The importance of hydrogel equilibrium hydration in progesterone permeation is emphasized.
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