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Abdelnabi D, Lastakchi S, Watts C, Atkins H, Hingtgen S, Valdivia A, McConville C. Local administration of irinotecan using an implantable drug delivery device stops high-grade glioma tumor recurrence in a glioblastoma tumor model. Drug Deliv Transl Res 2024; 14:3070-3088. [PMID: 38319555 DOI: 10.1007/s13346-024-01524-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/16/2024] [Indexed: 02/07/2024]
Abstract
The treatment for Glioblastoma is limited due to the presence of the blood brain barrier, which restricts the entry of chemotherapeutic drugs into the brain. Local delivery into the tumor resection margin has the potential to improve efficacy of chemotherapy. We developed a safe and clinically translatable irinotecan implant for local delivery to increase its efficacy while minimizing systemic side effects. Irinotecan-loaded implants were manufactured using hot melt extrusion, gamma sterilized at 25 kGy, and characterized for their irinotecan content, release, and drug diffusion. Their therapeutic efficacy was evaluated in a patient-derived xenograft mouse resection model of glioblastoma. Their safety and translatability were evaluated using histological analysis of brain tissue and serum chemistry analysis. Implants containing 30% and 40% w/w irinotecan were manufactured without plasticizer. The 30% and 40% implants showed moderate local toxicity up to 2- and 6-day post-implantation. Histopathology of the implantation site showed signs of necrosis at days 45 and 14 for the 30% and 40% implants. Hematological analysis and clinical chemistry showed no signs of serious systemic toxicity for either implant. The 30% implants had an 80% survival at day 148, with no sign of tumor recurrence. Gamma sterilization and 12-month storage had no impact on the integrity of the 30% implants. This study demonstrates that the 30% implants are a promising novel treatment for glioblastoma that could be quickly translated into the clinic.
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Affiliation(s)
- Dina Abdelnabi
- School of Pharmacy, Robert Aitken Institute for Clinical Research, Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, B15 2TT, UK
| | - Sarah Lastakchi
- School of Pharmacy, Robert Aitken Institute for Clinical Research, Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, B15 2TT, UK
| | - Colin Watts
- Department of Neurosurgery, University Hospitals Birmingham, NHS Foundation Trust, Birmingham, UK
| | - Hannah Atkins
- Department of Pathology and Laboratory Medicine, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Shawn Hingtgen
- Division of Molecular Pharmaceutics, UNC Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Alain Valdivia
- Division of Molecular Pharmaceutics, UNC Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Christopher McConville
- School of Pharmacy, Robert Aitken Institute for Clinical Research, Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, B15 2TT, UK.
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Longobardi G, Moore TL, Conte C, Ungaro F, Satchi-Fainaro R, Quaglia F. Polyester nanoparticles delivering chemotherapeutics: Learning from the past and looking to the future to enhance their clinical impact in tumor therapy. WILEY INTERDISCIPLINARY REVIEWS. NANOMEDICINE AND NANOBIOTECHNOLOGY 2024; 16:e1990. [PMID: 39217459 DOI: 10.1002/wnan.1990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 07/20/2024] [Accepted: 07/23/2024] [Indexed: 09/04/2024]
Abstract
Polymeric nanoparticles (NPs), specifically those comprised of biodegradable and biocompatible polyesters, have been heralded as a game-changing drug delivery platform. In fact, poly(α-hydroxy acids) such as polylactide (PLA), poly(lactide-co-glycolide) (PLGA), and poly(ε-caprolactone) (PCL) have been heavily researched in the past three decades as the material basis of polymeric NPs for drug delivery applications. As materials, these polymers have found success in resorbable sutures, biodegradable implants, and even monolithic, biodegradable platforms for sustained release of therapeutics (e.g., proteins and small molecules) and diagnostics. Few fields have gained more attention in drug delivery through polymeric NPs than cancer therapy. However, the clinical translational of polymeric nanomedicines for treating solid tumors has not been congruent with the fervor or funding in this particular field of research. Here, we attempt to provide a comprehensive snapshot of polyester NPs in the context of chemotherapeutic delivery. This includes a preliminary exploration of the polymeric nanomedicine in the cancer research space. We examine the various processes for producing polyester NPs, including methods for surface-functionalization, and related challenges. After a detailed overview of the multiple factors involved with the delivery of NPs to solid tumors, the crosstalk between particle design and interactions with biological systems is discussed. Finally, we report state-of-the-art approaches toward effective delivery of NPs to tumors, aiming at identifying new research areas and re-evaluating the reasons why some research avenues have underdelivered. We hope our effort will contribute to a better understanding of the gap to fill and delineate the future research work needed to bring polyester-based NPs closer to clinical application. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Emerging Technologies.
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Affiliation(s)
| | - Thomas Lee Moore
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
| | - Claudia Conte
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
| | - Francesca Ungaro
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
| | - Ronit Satchi-Fainaro
- Department of Physiology and Pharmacology, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Fabiana Quaglia
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
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3
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Jacobs GP. Irradiation of pharmaceuticals: A literature review. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2021.109795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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4
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Barbosa-Alfaro D, Andrés-Guerrero V, Fernandez-Bueno I, García-Gutiérrez MT, Gil-Alegre E, Molina-Martínez IT, Pastor-Jimeno JC, Herrero-Vanrell R, Bravo-Osuna I. Dexamethasone PLGA Microspheres for Sub-Tenon Administration: Influence of Sterilization and Tolerance Studies. Pharmaceutics 2021; 13:pharmaceutics13020228. [PMID: 33562155 PMCID: PMC7915986 DOI: 10.3390/pharmaceutics13020228] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/25/2021] [Accepted: 02/02/2021] [Indexed: 11/30/2022] Open
Abstract
Many diseases affecting the posterior segment of the eye require repeated intravitreal injections with corticosteroids in chronic treatments. The periocular administration is a less invasive route attracting considerable attention for long-term therapies. In the present work, dexamethasone-loaded poly(lactic-co-glycolic) acid (PLGA) microspheres (Dx-MS) were prepared using the oil-in-water (O/W) emulsion solvent evaporation technique. MS were characterized in terms of mean particle size and particle size distribution, external morphology, polymer integrity, drug content, and in vitro release profiles. MS were sterilized by gamma irradiation (25 kGy), and dexamethasone release profiles from sterilized and non-sterilized microspheres were compared by means of the similarity factor (f2). The mechanism of drug release before and after irradiation exposure of Dx-MS was identified using appropriate mathematical models. Dexamethasone release was sustained in vitro for 9 weeks. The evaluation of the in vivo tolerance was carried out in rabbit eyes, which received a sub-Tenon injection of 5 mg of sterilized Dx-MS (20–53 µm size containing 165.6 ± 3.6 µg Dx/mg MS) equivalent to 828 µg of Dx. No detectable increase in intraocular pressure was reported, and clinical and histological analysis of the ocular tissues showed no adverse events up to 6 weeks after the administration. According to the data presented in this work, the sub-Tenon administration of Dx-MS could be a promising alternative to successive intravitreal injections for the treatment of chronic diseases of the back of the eye.
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Affiliation(s)
- Deyanira Barbosa-Alfaro
- Innovation, Therapy and Pharmaceutical Development in Ophthalmology (InnOftal) Research Group, UCM 920415, Complutense University of Madrid, 28040 Madrid, Spain; (D.B.-A.); (V.A.-G.); (E.G.-A.); (I.T.M.-M.); (I.B.-O.)
- Departamento de Farmacia Galénica y Tecnología Alimentaria, Facultad de Farmacia, Universidad Complutense de Madrid (UCM), IdISSC, 28040 Madrid, Spain
| | - Vanessa Andrés-Guerrero
- Innovation, Therapy and Pharmaceutical Development in Ophthalmology (InnOftal) Research Group, UCM 920415, Complutense University of Madrid, 28040 Madrid, Spain; (D.B.-A.); (V.A.-G.); (E.G.-A.); (I.T.M.-M.); (I.B.-O.)
- Departamento de Farmacia Galénica y Tecnología Alimentaria, Facultad de Farmacia, Universidad Complutense de Madrid (UCM), IdISSC, 28040 Madrid, Spain
- Thematic Research Network in Ophthalmology (Oftared) Carlos III National Institute of Health, 28040 Madrid, Spain; (I.F.-B.); (J.C.P.-J.)
| | - Ivan Fernandez-Bueno
- Thematic Research Network in Ophthalmology (Oftared) Carlos III National Institute of Health, 28040 Madrid, Spain; (I.F.-B.); (J.C.P.-J.)
- Instituto Universitario de Oftalmobiología Aplicada (IOBA), Universidad de Valladolid, 47011 Valladolid, Spain;
| | | | - Esther Gil-Alegre
- Innovation, Therapy and Pharmaceutical Development in Ophthalmology (InnOftal) Research Group, UCM 920415, Complutense University of Madrid, 28040 Madrid, Spain; (D.B.-A.); (V.A.-G.); (E.G.-A.); (I.T.M.-M.); (I.B.-O.)
| | - Irene Teresa Molina-Martínez
- Innovation, Therapy and Pharmaceutical Development in Ophthalmology (InnOftal) Research Group, UCM 920415, Complutense University of Madrid, 28040 Madrid, Spain; (D.B.-A.); (V.A.-G.); (E.G.-A.); (I.T.M.-M.); (I.B.-O.)
- Departamento de Farmacia Galénica y Tecnología Alimentaria, Facultad de Farmacia, Universidad Complutense de Madrid (UCM), IdISSC, 28040 Madrid, Spain
- Thematic Research Network in Ophthalmology (Oftared) Carlos III National Institute of Health, 28040 Madrid, Spain; (I.F.-B.); (J.C.P.-J.)
| | - José Carlos Pastor-Jimeno
- Thematic Research Network in Ophthalmology (Oftared) Carlos III National Institute of Health, 28040 Madrid, Spain; (I.F.-B.); (J.C.P.-J.)
- Instituto Universitario de Oftalmobiología Aplicada (IOBA), Universidad de Valladolid, 47011 Valladolid, Spain;
- Department of Ophthalmology, Hospital Clínico Universitario of Valladolid, 47003 Valladolid, Spain
| | - Rocío Herrero-Vanrell
- Innovation, Therapy and Pharmaceutical Development in Ophthalmology (InnOftal) Research Group, UCM 920415, Complutense University of Madrid, 28040 Madrid, Spain; (D.B.-A.); (V.A.-G.); (E.G.-A.); (I.T.M.-M.); (I.B.-O.)
- Departamento de Farmacia Galénica y Tecnología Alimentaria, Facultad de Farmacia, Universidad Complutense de Madrid (UCM), IdISSC, 28040 Madrid, Spain
- Thematic Research Network in Ophthalmology (Oftared) Carlos III National Institute of Health, 28040 Madrid, Spain; (I.F.-B.); (J.C.P.-J.)
- Correspondence:
| | - Irene Bravo-Osuna
- Innovation, Therapy and Pharmaceutical Development in Ophthalmology (InnOftal) Research Group, UCM 920415, Complutense University of Madrid, 28040 Madrid, Spain; (D.B.-A.); (V.A.-G.); (E.G.-A.); (I.T.M.-M.); (I.B.-O.)
- Departamento de Farmacia Galénica y Tecnología Alimentaria, Facultad de Farmacia, Universidad Complutense de Madrid (UCM), IdISSC, 28040 Madrid, Spain
- Thematic Research Network in Ophthalmology (Oftared) Carlos III National Institute of Health, 28040 Madrid, Spain; (I.F.-B.); (J.C.P.-J.)
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Park K, Otte A, Sharifi F, Garner J, Skidmore S, Park H, Jhon YK, Qin B, Wang Y. Potential Roles of the Glass Transition Temperature of PLGA Microparticles in Drug Release Kinetics. Mol Pharm 2020; 18:18-32. [PMID: 33331774 DOI: 10.1021/acs.molpharmaceut.0c01089] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Poly(lactic-co-glycolic acid) (PLGA) has been used for long-acting injectable drug delivery systems for more than 30 years. The factors affecting the properties of PLGA formulations are still not clearly understood. The drug release kinetics of PLGA microparticles are influenced by many parameters associated with the formulation composition, manufacturing process, and post-treatments. Since the drug release kinetics have not been explainable using the measurable properties, formulating PLGA microparticles with desired drug release kinetics has been extremely difficult. Of the various properties, the glass transition temperature, Tg, of PLGA formulations is able to explain various aspects of drug release kinetics. This allows examination of parameters that affect the Tg of PLGA formulations, and thus, affecting the drug release kinetics. The impacts of the terminal sterilization on the Tg and drug release kinetics were also examined. The analysis of drug release kinetics in relation to the Tg of PLGA formulations provides a basis for further understanding of the factors controlling drug release.
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Affiliation(s)
- Kinam Park
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana 47907, United States.,College of Pharmacy, Purdue University, West Lafayette, Indiana 47907, United States.,Akina, Inc., West Lafayette, Indiana 47906, United States
| | - Andrew Otte
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Farrokh Sharifi
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - John Garner
- Akina, Inc., West Lafayette, Indiana 47906, United States
| | - Sarah Skidmore
- Akina, Inc., West Lafayette, Indiana 47906, United States
| | - Haesun Park
- Akina, Inc., West Lafayette, Indiana 47906, United States
| | - Young Kuk Jhon
- Office of Pharmaceutical Quality, Food and Drug Administration, Center for Drug Evaluation and Research, Silver Spring, Maryland 20993, United States
| | - Bin Qin
- Office of Generic Drugs, Food and Drug Administration, Center for Drug Evaluation and Research, Silver Spring, Maryland 20993, United States
| | - Yan Wang
- Office of Generic Drugs, Food and Drug Administration, Center for Drug Evaluation and Research, Silver Spring, Maryland 20993, United States
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6
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Tapia-Guerrero YS, Del Prado-Audelo ML, Borbolla-Jiménez FV, Giraldo Gomez DM, García-Aguirre I, Colín-Castro CA, Morales-González JA, Leyva-Gómez G, Magaña JJ. Effect of UV and Gamma Irradiation Sterilization Processes in the Properties of Different Polymeric Nanoparticles for Biomedical Applications. MATERIALS 2020; 13:ma13051090. [PMID: 32121529 PMCID: PMC7084644 DOI: 10.3390/ma13051090] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 02/19/2020] [Accepted: 02/25/2020] [Indexed: 02/07/2023]
Abstract
The sterilization processes of nanoparticles (NP) by autoclaving and filtration are two of the most utilized methods in the pharmaceutical industry but are not always a viable option. For this reason, the search for alternative options such as UV and gamma radiation is of interest. In this work, we evaluated both types of sterilization on two types of NP in solid state widely employed in the literature for biomedical applications, poly-(ε-caprolactone) and poly(D, L-lactide-co-glycolide) acid NP stabilized with polyvinyl alcohol. Physicochemical properties and cell viability were studied pre- and post-sterilization. The efficiency of irradiation sterilization was performed by a test of sterility using 1 × 108 CFU/mL of Escherichia coli, Staphylococcus aureus, and Candida albicans. Microbiological monitoring revealed that both methods were sufficient for sterilization. After the UV irradiation sterilization (100 µJ/cm2), no substantial changes were observed in the physicochemical properties of the NP or in the interaction or morphology of human glial cells, though 5 and 10 kGy of gamma irradiation showed slight changes of NP size as well as a decrease in cell viability (from 100 µg/mL of NP). At 5 kGy of radiation doses, the presence of trehalose as cryoprotectant reduces the cell damage with high concentrations of NP, but this did not occur at 10 kGy. Therefore, these methods could be highly effective and low-processing-time options for sterilizing NP for medical purposes. However, we suggest validating each NP system because these generally are of different polymer-composition systems.
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Affiliation(s)
- Y. S. Tapia-Guerrero
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, Ciudad de México 11340, Mexico; (Y.S.T.-G.); (J.A.M.-G.)
- Laboratorio de Medicina Genómica, Departamento de Genética (CENIAQ), Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra (INR-LGII), Ciudad de México 14389, Mexico; (F.V.B.-J.); (C.A.C.-C.)
| | - M. L. Del Prado-Audelo
- Laboratorio de Tecnología Farmacéutica, Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Cuautitlán Izcalli, Edo. de México 54740, Mexico;
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México 04510, Mexico
| | - F. V. Borbolla-Jiménez
- Laboratorio de Medicina Genómica, Departamento de Genética (CENIAQ), Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra (INR-LGII), Ciudad de México 14389, Mexico; (F.V.B.-J.); (C.A.C.-C.)
- Programa de Ciencias Biomédicas, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - D. M. Giraldo Gomez
- Departamento de Biología Celular y Tisular, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Edificio “A” 3er piso, Circuito Interior, Avenida Universidad 3000, Ciudad Universitaria, Coyoacán, Ciudad de México 04510, Mexico
- Unidad de Microscopía, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Edificio “A” planta baja, Circuito Interior, Avenida Universidad 3000, Ciudad Universitaria, Coyoacán, Ciudad de México 04510, Mexico
| | - I. García-Aguirre
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados (CINVESTAV-IPN), Ciudad de México 07360, Mexico
| | - C. A. Colín-Castro
- Laboratorio de Medicina Genómica, Departamento de Genética (CENIAQ), Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra (INR-LGII), Ciudad de México 14389, Mexico; (F.V.B.-J.); (C.A.C.-C.)
- Departamento de Infectología, (CENIAQ), Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra, Ciudad de México (CDMX) 14389, Mexico
| | - J. A. Morales-González
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, Ciudad de México 11340, Mexico; (Y.S.T.-G.); (J.A.M.-G.)
| | - G. Leyva-Gómez
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México 04510, Mexico
- Correspondence: (G.L.-G.); or (J.J.M.); Tel.: +52-(55)-5622-3899 (G.L.-G.); +52-(55)-5999-1000 (J.J.M.)
| | - J. J. Magaña
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, Ciudad de México 11340, Mexico; (Y.S.T.-G.); (J.A.M.-G.)
- Laboratorio de Medicina Genómica, Departamento de Genética (CENIAQ), Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra (INR-LGII), Ciudad de México 14389, Mexico; (F.V.B.-J.); (C.A.C.-C.)
- Escuela de Ingeniería, Departamento de Biotecnología, Instituto Tecnológico y de Estudios Superiores de Monterrey-Campus, Ciudad de México 14380, Mexico
- Correspondence: (G.L.-G.); or (J.J.M.); Tel.: +52-(55)-5622-3899 (G.L.-G.); +52-(55)-5999-1000 (J.J.M.)
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7
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Op 't Veld RC, Eerden M, Wagener FADTG, Kouwer PHJ, Jansen JA, Walboomers XF. Polyisocyanopeptide Hydrogels Are Effectively Sterilized Using Supercritical Carbon Dioxide. Tissue Eng Part C Methods 2019; 26:132-141. [PMID: 31847754 DOI: 10.1089/ten.tec.2019.0305] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Adequate sterilization procedures for soft biomaterials such as hydrogels are known to be challenging. These materials are delicate in structure, making them sensitive to harsh conditions and prone to damage. In this study, a suitable sterilization method for hydrogels composed of tri(ethylene glycol)-functionalized polyisocyanopeptides (PIC) was explored. These high biomimetic hydrogels are temperature and strain sensitive and have been presented as novel cell culturing matrices, wound dressings, and drug carriers. The methods that were investigated include autoclaving, γ-irradiation, ultraviolet (UV) light irradiation, and supercritical CO2 (scCO2) treatment. The results show that autoclaving and γ-irradiation have deleterious effects on the gelation behavior and mechanical characteristics of PIC. For γ-irradiation, cooling the gels on dry ice alleviated this negative impact, but not sufficiently enough to make the method viable. In contrast, UV light and scCO2 treatment do not affect the mechanical properties of the PIC gels. Studies with gels inoculated with 107 CFU/mL Gram-positive bacteria Staphylococcus aureus show that only scCO2 is capable of successfully sterilizing PIC hydrogels by achieving a 6-log reduction in bacterial load. It was concluded that, within the range of tested techniques, the sterilization of PIC is limited to scCO2.
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Affiliation(s)
- Roel C Op 't Veld
- Department of Dentistry-Biomaterials, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Dentistry-Orthodontics and Craniofacial Biology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - Frank A D T G Wagener
- Department of Dentistry-Orthodontics and Craniofacial Biology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Paul H J Kouwer
- Department of Molecular Materials, Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands
| | - John A Jansen
- Department of Dentistry-Biomaterials, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - X Frank Walboomers
- Department of Dentistry-Biomaterials, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
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8
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Schöneich C. Thiyl Radical Reactions in the Chemical Degradation of Pharmaceutical Proteins. Molecules 2019; 24:E4357. [PMID: 31795282 PMCID: PMC6930596 DOI: 10.3390/molecules24234357] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 11/16/2019] [Accepted: 11/18/2019] [Indexed: 01/01/2023] Open
Abstract
Free radical pathways play a major role in the degradation of protein pharmaceuticals. Inspired by biochemical reactions carried out by thiyl radicals in various enzymatic processes, this review focuses on the role of thiyl radicals in pharmaceutical protein degradation through hydrogen atom transfer, electron transfer, and addition reactions. These processes can lead to the epimerization of amino acids, as well as the formation of various cleavage products and cross-links. Examples are presented for human insulin, human and mouse growth hormone, and monoclonal antibodies.
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Affiliation(s)
- Christian Schöneich
- Department of Pharmaceutical Chemistry, University of Kansas, 2093 Constant Avenue, Lawrence, KS 66047, USA
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9
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Majewski AR, Chuong LM, Neill HM, Roberts AL, Jerry DJ, Dunphy KA. Sterilization of Silastic Capsules Containing 17β-Estradiol for Effective Hormone Delivery in Mus musculus. JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE : JAALAS 2018; 57. [PMID: 30314533 PMCID: PMC6241387 DOI: 10.30802/aalas-jaalas-18-000030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 04/16/2018] [Accepted: 06/01/2018] [Indexed: 11/05/2022]
Abstract
Silastic capsules are frequently used to study the physiologic effects of estrogen exposure in animal models. The Officeof Laboratory Animal Welfare requires the sterilization of nonpharmaceutical-grade compounds before use. We compared 2commonly used terminal sterilization methods-ionizing radiation (IR) and ethylene oxide (EO)-for their utility in sterilizingsilastic capsules containing 0.05 or 0.1 mg 17β-estradiol (E2). E2-specific ELISA demonstrated that serum estrogen levelsdid not differ between mice implanted with 0.05-mg E2 capsules that were sterilized with IR or EO and those implanted withnonsterilized capsules. Likewise, mammary gland morphology and progesterone receptor expression and proliferation inmammary epithelium were similar among mice treated with E2 capsules, regardless of sterilization method, and pregnant day15 mice. In addition, IR-sterilized 0.1-mg E2 pellets provided high serum E2. We conclude that neither ionizing radiation norethylene oxide degraded E2 or the cellulose matrix, suggesting that these methods of sterilization are appropriate to provideeffective sterile hormone capsules for animal research.
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Affiliation(s)
- Aliza R Majewski
- Department of Veterinary and Animal Science, University of Massachusetts, Amherst, Massachusetts
| | - Lynn M Chuong
- Department of Veterinary and Animal Science, University of Massachusetts, Amherst, Massachusetts
| | - Hannah M Neill
- Department of Veterinary and Animal Science, University of Massachusetts, Amherst, Massachusetts
| | - Amy L Roberts
- Department of Veterinary and Animal Science, University of Massachusetts, Amherst, Massachusetts
| | - D Joseph Jerry
- Department of Veterinary and Animal Science, University of Massachusetts, Amherst, Massachusetts
| | - Karen A Dunphy
- Department of Veterinary and Animal Science, University of Massachusetts, Amherst, Massachusetts
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10
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Evaluation of Sterilisation Techniques for Regenerative Medicine Scaffolds Fabricated with Polyurethane Nonbiodegradable and Bioabsorbable Nanocomposite Materials. Int J Biomater 2018; 2018:6565783. [PMID: 30405715 PMCID: PMC6192142 DOI: 10.1155/2018/6565783] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 06/18/2018] [Accepted: 08/09/2018] [Indexed: 12/31/2022] Open
Abstract
An effective sterilisation technique that maintains structure integrity, mechanical properties, and biocompatibility is essential for the translation of new biomaterials to the clinical setting. We aimed to establish an effective sterilisation technique for a biodegradable (POSS-PCL) and nonbiodegradable (POSS-PCU) nanocomposite scaffold that maintains stem cell biocompatibility. Scaffolds were sterilised using 70% ethanol, ultraviolet radiation, bleach, antibiotic/antimycotic, ethylene oxide, gamma irradiation, argon plasma, or autoclaving. Samples were immersed in tryptone soya broth and thioglycollate medium and inspected for signs of microbial growth. Scaffold surface and mechanical and molecular weight properties were investigated. AlamarBlue viability assay of adipose derived stem cells (ADSC) seeded on scaffolds was performed to investigate metabolic activity. Confocal imaging of rhodamine phalloidin and DAPI stained ADSCs was performed to evaluate morphology. Ethylene oxide, gamma irradiation, argon plasma, autoclaving, 70% ethanol, and bleach were effective in sterilising the scaffolds. Autoclaving, gamma irradiation, and ethylene oxide led to a significant change in the molecular weight distribution of POSS-PCL and gamma irradiation and ethylene oxide to that of POSS-PCU (p<0.05). UV, ethanol, gamma irradiation, and ethylene oxide caused significant changes in the mechanical properties of POSS-PCL (p<0.05). Argon was associated with significantly higher surface wettability and ADSC metabolic activity (p<0.05). In this study, argon plasma was an effective sterilisation technique for both nonbiodegradable and biodegradable nanocomposite scaffolds. Argon plasma should be further investigated as a potential sterilisation technique for medical devices.
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Naderi N, Griffin M, Malins E, Becer R, Mosahebi A, Whitaker IS, Seifalian AM. Slow chlorine releasing compounds: A viable sterilisation method for bioabsorbable nanocomposite biomaterials. J Biomater Appl 2015; 30:1114-24. [DOI: 10.1177/0885328215613666] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Objective Selection of the appropriate sterilisation method for biodegradable materials has been a challenging task. Many conventional sterilisation methods are not suitable for the next generation of biomaterials, mainly due to their complex composition, based on nanomaterials, often incorporating bioactive moieties. In this study, we investigate sterilisation efficacy of slow chlorine releasing compound sodium dichloroisocyanurate dihydrate (SDIC) for polyhedral oligomeric silsesquioxane (POSS)-poly(caprolactone urea-urethane) (PCL) scaffolds in comparison with conventional sterilisation methods. Methods POSS-PCL scaffolds were subjected to 70% ethanol, UV, and SDIC sterilisation methods. Samples were immersed in tryptone soya broth (TSB) and thioglycollate medium (THY) and after seven days visually inspected for signs of microbial growth. Bulk and surface properties and molecular weight distribution profiles of the scaffolds after sterilization were investigated using FTIR analysis, surface hydrophilicity, scanning electron microscopy analysis, tensile strength testing, and gel-permeation chromatography (GPC). Adipose-derived stem cells (ADSC) were seeded on the scaffolds and AlamarBlue® viability assay was performed to investigate cell metabolic activity. Confocal imaging of rhodamine phalloidin and Dapi stained ADSC on scaffolds was used to demonstrate cell morphology. Results GPC results showed that autoclaving led to a significant decrease in the molecular weight of POSS-PCL, whereas ethanol caused visible deformation of the polymer 3D structure and UV radiation did not effectively sterilise the scaffolds. AlamarBlue® analysis showed metabolic activity close to that of tissue culture plastic for ethanol and SDIC. Conclusion SDIC sterilisation can be safely applied to biodegradable scaffolds unsuitable for the more common sterilisation methods.
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Affiliation(s)
- Naghmeh Naderi
- Reconstructive Surgery & Regenerative Medicine Group, Institute of Life Sciences (ILS), Swansea University Medical School, Swansea, UK
- Welsh Centre for Burns & Plastic Surgery, ABMU Health Board, Swansea, UK
- UCL Centre for Nanotechnology & Regenerative Medicine, University College London, Royal Free London NHS Foundation Trust, London, UK
| | - Michelle Griffin
- UCL Centre for Nanotechnology & Regenerative Medicine, University College London, Royal Free London NHS Foundation Trust, London, UK
| | - Edward Malins
- Polymer Chemistry Laboratory, School of Engineering and Materials Science, Queen Mary, University of London, London, UK
| | - Remzi Becer
- Polymer Chemistry Laboratory, School of Engineering and Materials Science, Queen Mary, University of London, London, UK
| | - Afshin Mosahebi
- Department of Plastic Surgery, Royal Free London NHS Foundation Trust, London, UK
| | - Iain S Whitaker
- Reconstructive Surgery & Regenerative Medicine Group, Institute of Life Sciences (ILS), Swansea University Medical School, Swansea, UK
- Welsh Centre for Burns & Plastic Surgery, ABMU Health Board, Swansea, UK
| | - Alexander M Seifalian
- UCL Centre for Nanotechnology & Regenerative Medicine, University College London, Royal Free London NHS Foundation Trust, London, UK
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Dorati R, Genta I, Colzani B, Modena T, Bruni G, Tripodo G, Conti B. Stability Evaluation of Ivermectin-Loaded Biodegradable Microspheres. AAPS PharmSciTech 2015; 16:1129-39. [PMID: 25700978 DOI: 10.1208/s12249-015-0305-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 01/29/2015] [Indexed: 11/30/2022] Open
Abstract
A stability study was performed on ivermectin (IVM)-loaded biodegradable microparticles intended for injection in dogs. The rational was to evaluate the performances upon irradiation of a drug, such as IVM, with a few criticalities with respect to its stability, and toxicity. The goal was to provide valuable information for pharmaceutical scientists and manufacturers working in the veterinary area. The microspheres based on poly(D,L-lactide) and poly-(ε-caprolactone) and loaded with IVM and with the addition of alpha-tocopherol (TCP) as antioxidant were prepared by the emulsion solvent evaporation method and sterilized by gamma irradiation. Microsphere characterization in term of size, shape, polymer, and IVM stability upon irradiation was performed. The results show that the type of polymer significantly affects microsphere characteristics and performances. Moreover, suitably stable formulations can be achieved only by TCP addition.
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Caffeic Acid-PLGA Conjugate to Design Protein Drug Delivery Systems Stable to Irradiation. J Funct Biomater 2015; 6:1-13. [PMID: 25569163 PMCID: PMC4384096 DOI: 10.3390/jfb6010001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 12/24/2014] [Indexed: 11/23/2022] Open
Abstract
This work reports the feasibility of caffeic acid grafted PLGA (g-CA-PLGA) to design biodegradable sterile microspheres for the delivery of proteins. Ovalbumin (OVA) was selected as model compound because of its sensitiveness of γ-radiation. The adopted grafting procedure allowed us to obtain a material with good free radical scavenging properties, without a significant modification of Mw and Tg of the starting PLGA (Mw PLGA = 26.3 ± 1.3 kDa vs.Mw g-CA-PLGA = 22.8 ± 0.7 kDa; Tg PLGA = 47.7 ± 0.8 °C vs.Tg g-CA-PLGA = 47.4 ± 0.2 °C). By using a W1/O/W2 technique, g-CA-PLGA improved the encapsulation efficiency (EE), suggesting that the presence of caffeic residues improved the compatibility between components (EEPLGA = 35.0% ± 0.7% vs.EEg-CA-PLGA = 95.6% ± 2.7%). Microspheres particle size distribution ranged from 15 to 50 µm. The zeta-potential values of placebo and loaded microspheres were −25 mV and −15 mV, respectively. The irradiation of g-CA-PLGA at the dose of 25 kGy caused a less than 1% variation of Mw and the degradation patterns of the non-irradiated and irradiated microspheres were superimposable. The OVA content in g-CA-PLGA microspheres decreased to a lower extent with respect to PLGA microspheres. These results suggest that g-CA-PLGA is a promising biodegradable material to microencapsulate biological drugs.
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Chakoli AN, He J, Chayjan MA, Huang Y, Zhang B. Irradiation of poly(l-lactide) biopolymer reinforced with functionalized MWCNTs. RSC Adv 2015. [DOI: 10.1039/c5ra08319b] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The γirradiation increases the modulus and strength, decreases the melting point of poly(l-lactide) during sterilization. The functionalized carbon nanotubes accelerate the irradiation effect on mechanical and thermal properties of poly(l-lactide).
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Affiliation(s)
| | - Jinmei He
- School of Chemical Engineering and Technology
- State Key Laboratory of Urban Water Resource and Environment
- Harbin Institute of Technology
- Harbin 150001
- China
| | | | - Yudong Huang
- School of Chemical Engineering and Technology
- State Key Laboratory of Urban Water Resource and Environment
- Harbin Institute of Technology
- Harbin 150001
- China
| | - Baode Zhang
- School of Mechanical Engineering
- Liaoning Shihua University
- Fushun
- China
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15
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Dorati R, Genta I, Colzani B, Tripodo G, Conti B. Preliminary investigation on the design of biodegradable microparticles for ivermectin delivery: set up of formulation parameters. Drug Dev Ind Pharm 2014; 41:1182-92. [PMID: 24994001 DOI: 10.3109/03639045.2014.935395] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The aim was to design sterile biodegradable microparticulate drug delivery systems based on poly(dl-lactide) (PLA) and poly(ε-caprolactone) (PCL) and containing ivermectin (IVM), an antiparasitic drug, for subcutaneous administration in dogs. The drug delivery system should: (i) ensure a full 12-month protection upon single dose administration; (ii) be safe with particular attention regarding IVM dosage and its release, in order to prevent over dosage side effects. This preliminary work involves: polymer selection, evaluation of the effects of γ-irradiation on the polymers and IVM, investigation and set up of suitable microparticle preparation process and parameters, IVM-loaded microparticles in vitro release evaluation. Results of gel permeation chromatography analysis on the irradiated polymers and IVM mixtures showed that combination of IVM with the antioxidant α-tocopherol (TCP) reduces the damage extent induced by irradiation treatment, independently on the polymer type. Solvent evaporation process was successfully used for the preparation of PLA microparticles and appropriately modified; it was recognized as suitable for the preparation of PCL microparticles. Good process yields were achieved ranging from 76.08% to 94.72%; encapsulation efficiency was between 85.76% and 91.25%, independently from the polymer used. The type of polymer and the consequent preparation process parameters affected microparticle size that was bigger for PCL microparticles (480-800 µm) and solvent residual that was >500 ppm for PLA microparticles. In vitro release test showed significantly faster IVM release rates from PCL microparticles, with respect to PLA microparticles, suggesting that a combination of the polymers could be used to obtain the suitable drug release rate.
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Affiliation(s)
- Rosella Dorati
- Department of Drug Sciences, University of Pavia , Pavia , Italy
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16
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Abuhanoğlu G, Ozer AY. Radiation sterilization of new drug delivery systems. Interv Med Appl Sci 2014; 6:51-60. [PMID: 24936306 PMCID: PMC4047505 DOI: 10.1556/imas.6.2014.2.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 01/17/2014] [Accepted: 02/14/2014] [Indexed: 11/19/2022] Open
Abstract
Radiation sterilization has now become a commonly used method for sterilization of several active ingredients in drugs or drug delivery systems containing these substances. In this context, many applications have been performed on the human products that are required to be sterile, as well as on pharmaceutical products prepared to be developed. The new drug delivery systems designed to deliver the medication to the target tissue or organ, such as microspheres, nanospheres, microemulsion, and liposomal systems, have been sterilized by gamma (γ) and beta (β) rays, and more recently, by e-beam sterilization. In this review, the sterilization of new drug delivery systems was discussed other than conventional drug delivery systems by γ irradiation.
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Affiliation(s)
- Gürhan Abuhanoğlu
- Department of Radiopharmacy, Faculty of Pharmacy, Hacettepe University Sıhhiye, Ankara Turkey
| | - A Yekta Ozer
- Department of Radiopharmacy, Faculty of Pharmacy, Hacettepe University Sıhhiye, Ankara Turkey
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Checa-Casalengua P, Jiang C, Bravo-Osuna I, Tucker BA, Molina-Martínez IT, Young MJ, Herrero-Vanrell R. Preservation of biological activity of glial cell line-derived neurotrophic factor (GDNF) after microencapsulation and sterilization by gamma irradiation. Int J Pharm 2012; 436:545-54. [PMID: 22828071 DOI: 10.1016/j.ijpharm.2012.07.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 07/10/2012] [Accepted: 07/12/2012] [Indexed: 11/25/2022]
Abstract
A main issue in controlled delivery of biotechnological products from injectable biodegradable microspheres is to preserve their integrity and functional activity after the microencapsulation process and final sterilization. The present experimental work tested different technological approaches to maintain the biological activity of an encapsulated biotechnological product within PLGA [poly (lactic-co-glycolic acid)] microspheres (MS) after their sterilization by gamma irradiation. GDNF (glial cell line-derived neurotrophic factor), useful in the treatment of several neurodegenerative diseases, was chosen as a labile model protein. In the particular case of optic nerve degeneration, GDNF has been demonstrated to improve the damaged retinal ganglion cells (RGC) survival. GDNF was encapsulated in its molecular state by the water-in-oil-in-water (W/O/W) technique or as solid according to the solid-in-oil-in-water (S/O/W) method. Based on the S/O/W technique, GDNF was included in the PLGA microspheres alone (S/O/W 1) or in combination with an antioxidant (vitamin E, Vit E) (S/O/W 2). Microspheres were sterilized by gamma-irradiation (dose of 25 kGy) at room and low (-78 °C) temperatures. Functional activity of GDNF released from the different microspheres was evaluated both before and after sterilization in their potential target cells (retinal cells). Although none of the systems proposed achieved with the goal of totally retain the structural stability of the GDNF-dimer, the protein released from the S/O/W 2 microspheres was clearly the most biologically active, showing significantly less retinal cell death than that released from either W/O/W or S/O/W 1 particles, even in low amounts of the neurotrophic factor. According to the results presented in this work, the biological activity of biotechnological products after microencapsulation and sterilization can be further preserved by the inclusion of the active molecule in its solid state in combination with antioxidants and using low temperature (-78 °C) during gamma irradiation exposure.
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Affiliation(s)
- P Checa-Casalengua
- Dep. of Pharmacy and Pharmaceutical Technology, School of Pharmacy, Avd. Complutense s/n, Complutense University, Madrid 28040, Spain
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Choonara YE, Pillay V, Danckwerts MP, Carmichael TR, du Toit LC, Khan RA. Micromechanical and physical stability analysis of an irradiated poly (lactic-co-glycolic acid) donut-shaped minitablet device for intraocular implantation. Pharm Dev Technol 2012; 18:1186-203. [PMID: 22335771 DOI: 10.3109/10837450.2011.619541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
This study pragmatically characterized the micromechanical and physical stability of a poly(lactic-co-glycolic acid) (PLGA)-based ganciclovir (GCV)-loaded donut-shaped minitablet (DSMT) device for intraocular implantation. Thermal and spectroscopic analysis was performed on various drug-polymer permutations. Porositometric profiles were quantitatively analyzed coupled with qualitatively SEM imaging. The tensile strength (TS) and fracture energy (FE) of the device was also determined pre- and post-γ-sterilization. Inimitably, chemometric and molecular modeling provided a supportive confirmatory tool for establishing fundamental correlative suppositions between the transitioned surface morphology and the micromechanical stability after γ-irradiation. Isotherm plot volumes ranged between -0.028 ± 0.022 and 0.110 ± 0.005 m(2)/g for pre- and post-sterilized devices, respectively, revealing a microporous alteration in porosity. Pre-sterilized devices had larger pores (BJHa=286.22 vs. 192.49 Å) and lower FE (151.301 ± 6.089 N/m) and TS (26.396 ± 1.062 N) values while sterilized devices had crystalline matrices that facilitated the superiorly controlled drug release kinetcs obtained. DSC thermograms displayed the characteristic disordered crystallization of GCV and hydration exotherms resulting from ionization during γ-irradiation. FTIR spectrograms showed fingerprint molecular imprints of GCV and axial stretching of hybridized carbons of PLGA with no subversive drug-polymer interactions after γ-irradiation. Integration of the results inveterately revealed that compression and subsequent γ-irradiation of the device affected desirable micromechanical and solid-state stability behavior.
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Affiliation(s)
- Yahya E Choonara
- University of the Witwatersrand, Faculty of Health Sciences, Department of Pharmacy and Pharmacology , 7 York Road, Parktown, 2193, Johannesburg, South Africa
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Mohanan D, Gander B, Kündig TM, Johansen P. Encapsulation of antigen in poly(D,L-lactide-co-glycolide) microspheres protects from harmful effects of γ-irradiation as assessed in mice. Eur J Pharm Biopharm 2011; 80:274-81. [PMID: 22024408 DOI: 10.1016/j.ejpb.2011.10.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 10/06/2011] [Accepted: 10/10/2011] [Indexed: 01/16/2023]
Abstract
During the last two decades, synthetic polymers such as poly(lactide-co-glycolide) (PLGA) have been investigated for the development of nano- or microparticles as adjuvants or antigen vehicles. To enable transfer of this technology to human settings, the issue of sterilisation is of central importance. Since most polymers are heat-sensitive, sterilisation of polymeric microspheres for parenteral administration is assured either by costly and laborious aseptical preparation or the more preferred γ-irradiation. Many studies have investigated the effect of γ-irradiation on various physiochemical properties of the microspheres, but investigations on immunological effects are rare. We prepared poly(lactide-co-glycolide) (PLGA) microspheres containing ovalbumin (OVA) and tested the effect of γ-irradiation on the various immunological properties in mice. For reference, OVA was γ-irradiated and tested equivalently. The ability of encapsulated or non-encapsulated OVA to trigger activation of dendritic cells (DCs) was not affected by irradiation. However, while γ-irradiation of free OVA strongly influenced the antigen presentation, encapsulated OVA was not affected by irradiation. γ-Irradiation of OVA also reduced the immunogenicity in mice with regard to OVA-specific IgG1 production. In contrast, the antibody and the T-cell responses in mice immunised with PLGA-encapsulated OVA were similar irrespective of the γ-irradiation status. Hence, encapsulation of antigen into PLGA microspheres protects antigen from the potential detrimental effect of γ-irradiation leading to inactivation or altered immunogenicity. Sterilisation by γ-irradiation therefore enables a cost-effective production of PLGA-based antigen-delivery systems as compared to the more laborious and expensive aseptical production of such vaccines.
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Affiliation(s)
- Deepa Mohanan
- Department of Dermatology, University Hospital of Zurich, Zurich, Switzerland
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20
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Al-Kassas R, Donnelly RF, McCarron PA. Aminolevulinic acid-loaded Witepsol microparticles manufactured using a spray congealing procedure: implications for topical photodynamic therapy. J Pharm Pharmacol 2010. [DOI: 10.1211/jpp.61.09.0001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Abstract
Objectives
The aim was to enhance aminolevulinic acid (ALA) stability by incorporation into low-melting microparticles prepared using a spray congealing procedure and to evaluate temperature-triggered release, allowing topical bioavailability following melting at skin temperature.
Methods
ALA-loaded Witepsol microparticles were prepared using a novel spray congealing technique. Entrapment efficiency was compared with conventional emulsion-based methods and modelled drug release profiles determined using a membrane separation technique. Raised receiver medium temperature was used to determine triggered release. Bioavailability and lipid-mediated enhancement of ALA penetration were determined in excised murine skin.
Key findings
ALA-loaded Witepsol microparticles were spherical, with a mean diameter of 20 μm. Loading and stability studies demonstrated effective encapsulation, ranging from 91% to 100%, with no evidence of degradation to pyrazine derivatives. ALA release correlated with dissolution medium temperature, triggered at temperatures close to that of skin. Results suggested that molten Witepsol enhanced cutaneous permeation, whereas incorporation of microparticles in a semi-solid vehicle attenuated ALA penetration. Optimal use was direct application under occlusion.
Conclusions
Spray congealing is superior to the emulsion-based procedures with respect to encapsulation efficiency of ALA in Witepsol matrices, providing temperature-triggered release, enhanced stability and improved penetration of ALA through keratinised skin. These features could improve ALA delivery to superficial lesions as part of photodynamic therapy.
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Affiliation(s)
- Rasil Al-Kassas
- School of Pharmacy, Queen's University Belfast, Medical Biology Centre, Belfast, UK
| | - Ryan F Donnelly
- School of Pharmacy, Queen's University Belfast, Medical Biology Centre, Belfast, UK
| | - Paul A McCarron
- Department of Pharmacy and Pharmaceutical Sciences, University of Ulster, Coleraine, Co. Londonderry, UK
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Liu A, Qu S, Chao M, Zhu M, Weng J, Zhou Z. UHMWPE carrying estradiol to treat the particle-induced osteolysis-Processing and characterizing. J Biomed Mater Res A 2009; 90:496-505. [DOI: 10.1002/jbm.a.32120] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Effects of ionizing radiation sterilization on microparticulate drug delivery systems based on poly-α-hydroxyacids: an overview. J Drug Deliv Sci Technol 2009. [DOI: 10.1016/s1773-2247(09)50017-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Sánchez-Brunete JA, Dea MA, Rama S, Bolás F, Alunda JM, Torrado-Santiago S, Torrado JJ. Influence of the vehicle on the properties and efficacy of microparticles containing amphotericin B. J Drug Target 2008; 13:225-33. [PMID: 16051534 DOI: 10.1080/10611860500097107] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
New microparticles containing amphotericin B (AMB) have been developed and manufactured by spray drying. To this end albumin, polylactic-co-glycolic acids (PLGA) and poly(sebacic anhydride) have been employed as drug carriers. The selection of the solvent used to disperse the drug and the vehicle before spray drying was critical on production yields and physical properties of the microparticles. Once particle size, morphology and dispersability in some aqueous media were shown to be acceptable for an intravenous administration, in vivo efficacy was evaluated and compared with the reference medicine Fungizone. Microparticles prepared with albumin, albumin heated at a high temperature, some kinds of PLGA or polyanhydride, as well as Fungizone, were tested in an experimental hamster model of infection with Leishmania infantum, by evaluating the evolution of parasitic burdens in spleen, liver and antibody responses. After the injection of three doses corresponding to 2 mg of AMB per kilogram each, diverse reactions were reported depending on the vehicle. The best dispersability, reduction of parasites and antibody response were achieved when the treatment was performed with AMB in albumin microspheres.
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Affiliation(s)
- J A Sánchez-Brunete
- Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, Complutense University, Madrid, 28040, Spain
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Dorati R, Colonna C, Serra M, Genta I, Modena T, Pavanetto F, Perugini P, Conti B. gamma-Irradiation of PEGd,lPLA and PEG-PLGA multiblock copolymers. I. Effect of irradiation doses. AAPS PharmSciTech 2008; 9:718-25. [PMID: 18528761 DOI: 10.1208/s12249-008-9103-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2008] [Accepted: 04/29/2008] [Indexed: 11/30/2022] Open
Abstract
To evaluate the effects of different gamma irradiation doses on PEGd,lPLA and PEG-PLGA multiblock copolymers. The behaviour of the multiblock copolymers to irradiation was compared to that of PLA, PLGA polymers. PEGd,lPLA, PEG-PLGA, PLA and PLGA polymers were irradiated by using a (60)Co irradiation source at 5, 15, 25 and 50 kGy total dose. Characterization was performed on all samples before and after irradiation, by nuclear magnetic resonance (NMR), infrared absorption spectrophotometry (FTIR) and gel permeation chromatography (GPC). The effect of gamma irradiation on polymer stability was also evaluated. Results of NMR and FTIR suggest an increase in -OH and -COOH groups, attributed to scission reactions induced by irradiation treatment. Data of GPC analysis showed that the weight average molecular weight (Mw) of polymer samples decreased with increasing irradiation dose. The extent of Mw degradation expressed as percentage of Mw reduction was more prominent for polymers with high molecular weight as PEGd,lPLA and PLA. The dominant effect of gamma-irradiation on both polymer samples was chain scission. The multiblock copolymer PEGd,lPLA presented higher sensitivity to irradiation treatment with respect to PLA, likely due to the presence of PEG in the matrix. The effect of gamma irradiation continues over a much longer period of time after gamma irradiation has been performed. It is suggested that the material reacts with oxygen to form peroxyl free radicals, which may further undergo degradation reactions during storage after irradiation.
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Wischke C, Schwendeman SP. Principles of encapsulating hydrophobic drugs in PLA/PLGA microparticles. Int J Pharm 2008; 364:298-327. [PMID: 18621492 DOI: 10.1016/j.ijpharm.2008.04.042] [Citation(s) in RCA: 548] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2008] [Revised: 04/29/2008] [Accepted: 04/29/2008] [Indexed: 10/22/2022]
Abstract
Injectable biodegradable and biocompatible copolymers of lactic and glycolic acid (PLGA) are an important advanced delivery system for week-to-month controlled release of hydrophobic drugs (e.g., from biopharmaceutical classification system class IV), which often display poor oral bioavailability. The basic principles and considerations to develop such microparticle formulations is reviewed here based on a comprehensive study of papers and patents from the beginnings of hydrophobic drug encapsulation in polylactic acid and PLGA up through the very recent literature. Challenges with the diversity of drug properties, microencapsulation methods, and organic solvents are evaluated in light of the precedence of commercialized formulations and with a focus on decreasing the time to lab-scale encapsulation of water-insoluble drug candidates in the early stage of drug development. The influence of key formulation variables on final microparticle characteristics, and how best to avoid undesired microparticle properties, is analyzed mechanistically. Finally, concepts are developed to manage the common issues of maintaining sink conditions for in vitro drug release assays of hydrophobic compounds. Overall, against the backdrop of an increasing number of new, poorly orally available drug entities entering development, microparticle delivery systems may be a viable strategy to rescue an otherwise undeliverable substance.
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Affiliation(s)
- Christian Wischke
- Department of Pharmaceutical Sciences, University of Michigan, 428 Church Street, Ann Arbor, MI 48109-1065, USA
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Maksimenko O, Pavlov E, Toushov E, Molin A, Stukalov Y, Prudskova T, Feldman V, Kreuter J, Gelperina S. Radiation sterilisation of doxorubicin bound to poly(butyl cyanoacrylate) nanoparticles. Int J Pharm 2008; 356:325-32. [DOI: 10.1016/j.ijpharm.2008.01.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2007] [Revised: 12/23/2007] [Accepted: 01/05/2008] [Indexed: 11/16/2022]
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Alvarez H, Castro C, Moujir L, Perera A, Delgado A, Soriano I, Evora C, Sánchez E. Efficacy of ciprofloxacin implants in treating experimental osteomyelitis. J Biomed Mater Res B Appl Biomater 2008; 85:93-104. [PMID: 17696153 DOI: 10.1002/jbm.b.30921] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Ciprofloxacin (CFX) implants containing poly(D,L-lactide) and calcium phosphates (tricalcium phosphate and hydroxyapatite) was evaluated in 50 rabbits in an experimental osteomyelitis model. Their femoral cavity was inoculated with Staphylococcus aureus. After 2 weeks, the infected focus was cleaned out and the delivery system implanted. The infection and subsequent response to treatment were evaluated by microbiological analysis, biochemical and hematological markers, body weight, temperature, clinical signs, X-rays, and histology. Infected bone cultures, treated with CFX implants, showed reduced bacterial growth against controls. All CFX was released within 6 weeks. All animals recovered within 4 weeks. Even 12 weeks after implantation, no recurrence of infection was observed. Serum C-reactive protein, platelet, and leukocyte levels increased in all animals before treatment, and 4 weeks after it were maintained or rose in control animals, while decreased to normal levels in treated ones. Body weight was characterized by pretreatment losses, then gains during recuperation, or further loss in untreated animals; with no significant intraindividual differences in body temperature. Body weight, leucocytes, platelets, and C-reactive protein turned out to be highly useful markers for monitoring this kind of infection and its treatment. CFX implants demonstrated to be an effective therapy for S. aureus bone infection. Their efficacy was also reflected in decreasing severity of clinical signs, nonprogress of radiological signs indicative of infection, and good integration into bone structure. Histological examination revealed repair, with new bone formation extending into implants.
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Affiliation(s)
- H Alvarez
- Traumatology Service, Hospitén Rambla, Tenerife, Spain
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28
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Ražem D, Katušin-Ražem B. The effects of irradiation on controlled drug delivery/controlled drug release systems. Radiat Phys Chem Oxf Engl 1993 2008. [DOI: 10.1016/j.radphyschem.2007.06.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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29
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Degradable Polymer Microspheres for Controlled Drug Delivery. ADVANCES IN POLYMER SCIENCE 2007. [DOI: 10.1007/3-540-45734-8_3] [Citation(s) in RCA: 278] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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30
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Arifin DY, Lee LY, Wang CH. Mathematical modeling and simulation of drug release from microspheres: Implications to drug delivery systems. Adv Drug Deliv Rev 2006; 58:1274-325. [PMID: 17097189 DOI: 10.1016/j.addr.2006.09.007] [Citation(s) in RCA: 393] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2006] [Accepted: 09/04/2006] [Indexed: 11/21/2022]
Abstract
This article aims to provide a comprehensive review of existing mathematical models and simulations of drug release from polymeric microspheres and of drug transport in adjacent tissues. In drug delivery systems, mathematical modeling plays an important role in elucidating the important drug release mechanisms, thus facilitating the development of new pharmaceutical products by a systematic, rather than trial-and-error, approach. The mathematical models correspond to the known release mechanisms, which are classified as diffusion-, swelling-, and erosion-controlled systems. Various practical applications of these models which explain experimental data are illustrated. The effect of gamma-irradiation sterilization on drug release mechanism from erosion-controlled systems will be discussed. The application of existing models to nanoscale drug delivery systems specifically for hydrophobic and hydrophilic molecules is evaluated. The current development of drug transport modeling in tissues utilizing computational fluid dynamics (CFD) will also be described.
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Affiliation(s)
- Davis Yohanes Arifin
- Molecular Engineering of Biological and Chemical Systems Program, Singapore-MIT Alliance, 4 Engineering Drive 3, Singapore 117576, Singapore
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31
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Felt-Baeyens O, Eperon S, Mora P, Limal D, Sagodira S, Breton P, Simonazzi B, Bossy-Nobs L, Guex-Crosier Y, Gurny R. Biodegradable scleral implants as new triamcinolone acetonide delivery systems. Int J Pharm 2006; 322:6-12. [PMID: 16824708 DOI: 10.1016/j.ijpharm.2006.05.053] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2005] [Revised: 04/20/2006] [Accepted: 05/03/2006] [Indexed: 10/24/2022]
Abstract
The goal of this study was to develop ocular scleral implants able to release triamcinolone acetonide (TA) overall several months. Scleral discs were manufactured by a compression-molding method using a new synthetic polymer, poly(methylidene malonate) (PMM2.1.2), as matrix. Implants with good mechanical properties adapted for in vivo implantation have been obtained when using high M(w) PMM2.1.2 (100,000 - 150,000 Da) associated with ethoxylated derivatives of stearic acid (Simulsol) or oligomers of methylidene malonate as plasticizer. After implantation in rabbit eyes, scleral implants showed a good ocular biocompatibility. Indeed, the clinical follow-up and ocular inflammation parameters, such as inflammatory cell number and protein content in aqueous humor, demonstrated that implants were well tolerated and did not provoke abnormal inflammation. Implants were able to release significant concentrations of TA in the vitreous and the sclera throughout 5 weeks.
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Affiliation(s)
- O Felt-Baeyens
- Department of Pharmaceutics and Biopharmaceutics, School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, 30 Quai Ernest-Ansermet, CH-1211 Geneva 4, Switzerland
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32
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Williams HE, Huxley J, Claybourn M, Booth J, Hobbs M, Meehan E, Clark B. The effect of γ-irradiation and polymer composition on the stability of PLG polymer and microspheres. Polym Degrad Stab 2006. [DOI: 10.1016/j.polymdegradstab.2006.01.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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33
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Dillen K, Vandervoort J, Van den Mooter G, Ludwig A. Evaluation of ciprofloxacin-loaded Eudragit® RS100 or RL100/PLGA nanoparticles. Int J Pharm 2006; 314:72-82. [PMID: 16600538 DOI: 10.1016/j.ijpharm.2006.01.041] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2005] [Revised: 01/23/2006] [Accepted: 01/26/2006] [Indexed: 11/26/2022]
Abstract
The objective of present study was to prepare positively charged ciprofloxacin-loaded nanoparticles providing a controlled release formulation. The particles were prepared by water-in-oil-in-water (w/o/w) emulsification and solvent evaporation, followed by high-pressure homogenisation. Two non-biodegradable positively charged polymers, Eudragit RS100 and RL100, and the biodegradable polymer poly(lactic-co-glycolic acid) or PLGA were used alone or in combination, with varying ratios. The formulations were evaluated in terms of particle size and zeta potential. Differential scanning calorimetry measurements were carried out on the nanoparticles and on the pure polymers Eudragit and PLGA. Drug loading and release properties of the nanoparticles were examined. The antimicrobial activity against Pseudomonas aeruginosa and Staphylococcus aureus was determined. During solvent evaporation, the size and zeta potential of the nanoparticles did not change significantly. The mean diameter was dependent on the presence of Eudragit and on the viscosity of the organic phase. The zeta potential of all Eudragit containing nanoparticles was positive in ultrapure water (around +21/+25 mV). No burst effect but a prolonged drug release was observed from all formulations. The particles' activity against P. aeruginosa and S. aureus was comparable with an equally concentrated ciprofloxacin solution.
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Affiliation(s)
- Kathleen Dillen
- Laboratory of Pharmaceutical Technology and Biopharmacy, Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium
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Carrascosa C, Espejo L, Torrado S, Torrado JJ. Effect of gamma-sterilization process on PLGA microspheres loaded with insulin-like growth factor-I (IGF-I). J Biomater Appl 2004; 18:95-108. [PMID: 14621336 DOI: 10.1177/088532803038026] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The influence of gamma-sterilization on the physicochemical properties of a controlled release formulation for the insulin-like growth factor-I (IGF-I) was investigated in this study. Recombinant human insulin-like growth factor-I (rhIGF-I) was efficiently entrapped in poly (D,L-lactide-co-glycolide) (PLGA) microspheres by water-in-oil-in-water (W/O/W) solvent evaporation technique. Microspheres were irradiated at a dose of 25kGy and evaluated by means of scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The stability of the released protein was investigated by circular dichroism (CD) and sodium dodecyl sulfate polyacrilamide gel electrophoresis (SDS-PAGE). No difference was noticed in microsphere size and morphology before and after irradiation. Drug loading remains essentially the same after the sterilization process. However, rhIGF-I aggregation was detected by electrophoresis. In addition, subtle changes in DSC pattern were noticed for irradiated microspheres. In vitro drug release from irradiated microspheres was also affected, showing an increased burst effect. From this results it can be concluded that gamma-sterilization process causes changes in the properties of rhIGF-I loaded microspheres.
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Affiliation(s)
- C Carrascosa
- Departamento de Farmacia y Tecnologia Farmacéutica, cultad de Farmacia Plaza Ram6nóy Cajal E-28040 Madrid, Spain
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35
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Freitas S, Merkle HP, Gander B. Ultrasonic atomisation into reduced pressure atmosphere—envisaging aseptic spray-drying for microencapsulation. J Control Release 2004; 95:185-95. [PMID: 14980767 DOI: 10.1016/j.jconrel.2003.11.005] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2003] [Accepted: 11/12/2003] [Indexed: 11/30/2022]
Abstract
A novel spray-drying technique consisting of feeding a fluid through an ultrasonic atomiser, drying the spray under reduced pressure and collecting the particles in a liquid bath was evaluated. Drying by mild vacuum instead of hot air, as employed in conventional spray-drying, and simple particle recovery render this method suitable for aseptic microsphere preparation. As a model system, the protein bovine serum albumin (BSA) was encapsulated in poly(lactic-co-glycolic acid) microspheres. Particle yields of above 80% exceeded largely values found for conventional laboratory-scale spray-drying equipment. BSA encapsulation efficiency mostly ranged in the region of 60%, with losses probably occurring through partitioning into the aqueous collection bath. Mean particle sizes ranged from 13 to 24 microm, depending on the polymer type and solvent; particle size distributions were excellently reproducible. The microspheres were found to be very porous and exhibited a pronounced 24-h burst release of above 50% of total dose, probably promoted by the porosity. However, when more concentrated polymer solutions (8% instead of 5% (w/w)) were employed, burst release reduced to an average of 16%.
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Affiliation(s)
- Sergio Freitas
- Institute of Pharmaceutical Sciences, ETH Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
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36
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Faisant N, Siepmann J, Richard J, Benoit JP. Mathematical modeling of drug release from bioerodible microparticles: effect of gamma-irradiation. Eur J Pharm Biopharm 2003; 56:271-9. [PMID: 12957642 DOI: 10.1016/s0939-6411(03)00104-8] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Bioerodible polymers used in controlled drug delivery systems, such as poly(lactic-co-glycolic acid) (PLGA) undergo radiolytic degradation during gamma-irradiation. In spite of the considerable practical importance, yet only little knowledge is available on the consequences of this sterilization method on the resulting drug release patterns in a quantitative way. The major objectives of the present study were: (i) to monitor the effects of different gamma-irradiation doses on the physicochemical properties of drug-free and drug-loaded, PLGA-based microparticles; (ii) to analyze the obtained experimental results using adequate mathematical models; (iii) to get further insight into the occurring physical and chemical phenomena; and (iv) to relate the applied gamma-irradiation dose in a quantitative way to the resulting drug release rate. 5-Fluorouracil-loaded, PLGA-based microparticles were prepared with an oil-in-water solvent extraction method and exposed to gamma-irradiation doses ranging from 0 to 33 kGy. Size exclusion chromatography, differential scanning calorimetry, scanning electron microscopy, particle size analysis, determination of the actual drug loading and in vitro drug release kinetics were used to study the effects of the gamma-irradiation dose on the physicochemical properties of the microparticles. Two mathematical models-a simplified and a more comprehensive one-were used to analyze the experimental results. The simplified model considers drug diffusion based on Fick's second law for spherical geometry and a Higuchi-like pseudo-steady-state approach. The complex model combines Monte Carlo simulations (describing polymer erosion) with partial differential equations quantifying drug diffusion with time-, position- and direction-dependent diffusivities. Interestingly, exponential relationships between the gamma-irradiation dose and the initial drug diffusivity within the microparticles could be established. Based on this knowledge both models were used to predict the resulting drug release kinetics as a function of the gamma-irradiation dose. Importantly, the theoretical predictions were confirmed by experimental results.
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Affiliation(s)
- N Faisant
- INSERM ERIT-M 0104, Université d'Angers, Angers, France
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37
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Kryczka T, Marciniec B, Popielarz-Brzezinska M, Bero M, Kasperczyk J, Dobrzyński P, Kazimierczuk Z, Grieb P. Effect of gamma-irradiation on cladribine and cladribine-containing biodegradable copolymers. J Control Release 2003; 89:447-56. [PMID: 12737847 DOI: 10.1016/s0168-3659(03)00156-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The aims of this study were to assess the effects of sterilization with gamma-irradiation on (i). bulk cladribine and (ii). cladribine-containing biodegradable copolymers. The stability of cladribine upon irradiation was confirmed by TLC, HPLC, UV, IR, DSC, rentgenography and electron microscopy. The stability of copolymers containing cladribine upon irradiation was assessed by IR, DSC and EPR. In vitro kinetics of nucleoside release from the copolymers before and after irradiation were compared, and only slight changes were found. Results of our study indicate that gamma-irradiation can be safely applied for the sterilization of cladribine or cladribine-containing copolymers for medical purposes.
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Affiliation(s)
- Tomasz Kryczka
- Medical Research Centre, Polish Academy of Sciences, Pawińskiego 5, 02-106 Warsaw, Poland.
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38
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Faucitano A, Buttafava A, Montanari L, Cilurzo F, Conti B, Genta I, Valvo L. Radiation-induced free radical reactions in polymer/drug systems for controlled release: an EPR investigation. Radiat Phys Chem Oxf Engl 1993 2003. [DOI: 10.1016/s0969-806x(02)00404-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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39
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Lee TH, Wang J, Wang CH. Double-walled microspheres for the sustained release of a highly water soluble drug: characterization and irradiation studies. J Control Release 2002; 83:437-52. [PMID: 12387951 DOI: 10.1016/s0168-3659(02)00235-3] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Composite double-walled microspheres with biodegradable poly(L-lactic acid) (PLLA) shells and poly(D,L-lactic-co-glycolic acid) (PLGA) cores were fabricated with highly water-soluble etanidazole entrapped within the core as solid crystals. This paper discusses the characterization, in vitro release and the effects of irradiation on this class of microsphere. Through the variation of polymer mass ratios, predictable shell and core dimensions could be fabricated and used to regulate the release rates. A direct and simple method was devised to determine the composition of the shell and core polymer based on the different solubilities of the polymer pair in ethyl acetate. A distribution theory based on solubility parameter explains why highly hydrophilic etanidazole has the tendency to be distributed consistently to the more hydrophilic polymer. Release profiles for normal double-walled samples have about 80% of drug released over 10 days after the initial time lag, while for irradiated double-walled samples, the sustained release lasted for more than 3 weeks. Although sustained release was short of the desired 6-8 weeks required for therapy, a low initial burst of less than 5% and time lags that can be manipulated, allows for administration of these microspheres together with traditional ones to generate pulsatile or new type of releases. The effects of irradiation were also investigated to determine the suitability of these double-walled microspheres as delivery devices to be used in conjunction with radiotherapy. Typical therapeutic dosage of 50 Gy was found to be too mild to have noticeable effects on the polymer and its release profiles, while, sterilization dosages of 25 kGy, lowered the glass transition temperatures and crystalline melting point, indirectly indicating a decrease in molecular weight. This accelerated degradation of the polymer, hence releasing the drug.
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Affiliation(s)
- Teng Huar Lee
- Department of Chemical and Environmental Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore
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40
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Faisant N, Siepmann J, Oury P, Laffineur V, Bruna E, Haffner J, Benoit J. The effect of gamma-irradiation on drug release from bioerodible microparticles: a quantitative treatment. Int J Pharm 2002; 242:281-4. [PMID: 12176264 DOI: 10.1016/s0378-5173(02)00188-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The two major objectives of this study were: (i) to monitor the effect of different gamma-irradiation doses (4-33 kGy) on the release kinetics from 5-fluorouracil (5-FU)-loaded poly(D,L-lactide-co-glycolide) (PLGA)-based microparticles, and (ii) to analyze the obtained experimental data with a new mathematical model giving insight into the occurring mass transport phenomena. Drug release was found to depend significantly on the applied gamma-irradiation dose. Interestingly, the obtained release profiles were all biphasic: a rapid initial drug release phase ("burst") was followed by a slower, approximately constant drug release phase. Surprisingly, only the initial rapid drug release was accelerated by gamma-irradiation; the subsequent zero-order phase was almost unaffected. Importantly, the new mathematical model which is based on Fick's second law of diffusion and which considers polymer degradation was applicable to all the investigated systems. In addition, the gamma-irradiation dose could be quantitatively related to the resulting drug release rate. In conclusion, diffusion seems to be the dominating release rate controlling mechanism in all cases, with a significant contribution of the polymer degradation process.
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Affiliation(s)
- N Faisant
- INSERM ERIT-M 0104, Université d'Angers, 10 rue André Boquel, 49100, Angers, France
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41
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Montanari L, Cilurzo F, Conti B, Genta I, Groppo A, Valvo L, Faucitano A, Buttafava A. Gamma irradiation effects and EPR investigation on poly(lactide-co-glycolide) microspheres containing bupivacaine. FARMACO (SOCIETA CHIMICA ITALIANA : 1989) 2002; 57:427-33. [PMID: 12088056 DOI: 10.1016/s0014-827x(02)01220-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The effects of gamma radiation on the stability of microspheres made of a polylactide-co-glycolide 50:50 copolymer (PLGA) and loaded with 40% bupivacaine (BU) were studied. The radiolysis mechanisms of BU and BU-loaded microspheres were investigated by using electronic paramagnetic resonance (EPR) analysis. Microspheres were prepared by means of a spray drying method. Gamma Irradiation was carried out in the open, at the dose of 25 kGy, by using a 60Co source. The stability of BU-loaded microspheres was evaluated over a 1-year period on the basis of drug content and dissolution profile. Non-irradiated microspheres were stable over the whole period under consideration. Immediately after irradiation the amount of BU released after 24 h from irradiated microspheres increased from 17 to 25%; in the following 3 months of storage it increased to about 35%, and then it kept constant for 1 year. Radicals generated by BU irradiation were identified by EPR analysis; the sensitivity to gamma radiation of BU was about four times lower than that of PLGA. Furthermore, the EPR spectra of loaded microspheres showed that the relative abundance of BU radicals plus PLGA radicals was proportionate to the electronic fractions of the components; this implies that no spin transfer BU/PLGA had occurred during gamma irradiation.
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Affiliation(s)
- L Montanari
- Istituto di Chimica Farmaceutica e Tossicologica, Università degli Studi di Milano, Milan, Italy.
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Konan YN, Gurny R, Allémann E. Preparation and characterization of sterile and freeze-dried sub-200 nm nanoparticles. Int J Pharm 2002; 233:239-52. [PMID: 11897428 DOI: 10.1016/s0378-5173(01)00944-9] [Citation(s) in RCA: 191] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The feasibility of producing sterile and freeze-dried polyester nanoparticles was investigated. Various poly(D,L-lactide-co-glycolide) and poly(D,L-lactide) were selected as biodegradable polymers. Using the salting-out procedure, process parameters were optimized to obtain sub-200 nm particles. After purification, the nanoparticle suspensions containing different lyoprotectants were sterilized by filtration. Freeze-drying was performed using vials covered with 0.22 microm membrane filters in order to preserve the suspensions from bacterial contamination. Sterility was assessed on the final product according to pharmacopoeial requirements using the membrane filtration method. With all polymers tested, sub-200 nm particles could be obtained. Nanoparticles with a size as low as 102 nm were prepared with good reproducibility and narrow size distribution. Upon freeze-drying, it appeared that complete redispersion of all types of polyester nanoparticles could be obtained in presence of the lyoprotectants tested such as saccharides while aggregation was observed without lyoprotectant. Sterility testing showed no microbial contamination indicating that sterile nanoparticulate formulations have been achieved.
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Affiliation(s)
- Yvette N Konan
- School of Pharmacy, University of Geneva, 30, quai Ernest Ansermet, CH-1211 Geneva 4 , Switzerland
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43
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Caliş S, Bozdag S, Kaş HS, Tunçay M, Hincal AA. Influence of irradiation sterilization on poly(lactide-co-glycolide) microspheres containing anti-inflammatory drugs. FARMACO (SOCIETA CHIMICA ITALIANA : 1989) 2002; 57:55-62. [PMID: 11902646 DOI: 10.1016/s0014-827x(01)01171-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Gamma-irradiation is finding increasing use in the sterilization of pharmaceutical products. However, irradiation might also affect the performance of drug delivery systems. In this study, the influence of gamma-irradiation on the physicochemical properties of two commonly used non-steroidal anti-inflammatory drugs (NSAIDs) [naproxen sodium (NS) and diclofenac sodium (DS)] was investigated. The drugs were incorporated in poly(lactide-co-glycolide) (PLGA, 50:50; molecular weight 34000 or 88000 Da) microspheres. The biodegradable microspheres were irradiated at doses of 5, 15, 25 kGy using a 60Co source. Drug loading of irradiated and non-irradiated microspheres with both 34000 and 88000 Da polymers were essentially the same. A significant difference was noticed in the particle sizes of the irradiated as compared to the non-irradiated formulations. Notably, in release studies, the amount of active substance released from PLGA microspheres showed an increase with increasing irradiation dose. In DSC, the glass transition temperatures (Tg) of microspheres exhibited a slow increase with irradiation dose.
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Affiliation(s)
- Sema Caliş
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, Ankara, Turkey.
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44
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Montanari L, Cilurzo F, Valvo L, Faucitano A, Buttafava A, Groppo A, Genta I, Conti B. Gamma irradiation effects on stability of poly(lactide-co-glycolide) microspheres containing clonazepam. J Control Release 2001; 75:317-30. [PMID: 11489319 DOI: 10.1016/s0168-3659(01)00401-1] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This work was aimed at evaluating the effects of gamma irradiation on the stability of microspheres made of a poly(lactide-co-glycolide) copolymer (PLGA) and loaded with 15% w/w of clonazepam (CLO). The influence of CLO on PLGA radiolysis mechanisms and the identification of possible irradiation markers were also investigated. Microspheres were prepared by means of a spray-drying method. gamma Irradiation was carried out either under vacuum or in air, at a dose of 25 kGy, by using a 60Co source. The stability of CLO loaded microspheres was evaluated over a 6-month period on the basis of drug content and dissolution profile. Radiolysis mechanisms were investigated by using electronic paramagnetic resonance (EPR) analysis. The microspheres irradiated under vacuum were stable over the considered period of time. After irradiation in air, CLO release rate increased by approximately 10%, and did not change further in the following period of storage. The EPR analysis showed some radicals arising from both the polymeric matrix and the active ingredient. Polymer/CLO spin transfer reactions suggest that CLO had a radio-stabilising effect on the polymeric matrix. In the loaded microspheres, the intensity in time of the CLO radical signal is sufficient for its possible use as irradiation marker.
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Affiliation(s)
- L Montanari
- Istituto di Chimica Farmaceutica e Tossicologica, Università di Milano, v. le Abruzzi 42, 20131, Milan, Italy.
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