251
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Pandit V, Pai RS, Yadav V, Devi K, Surekha BB, Inamdar MN, Suresh S. Pharmacokinetic and pharmacodynamic evaluation of floating microspheres of metformin hydrochloride. Drug Dev Ind Pharm 2012; 39:117-27. [DOI: 10.3109/03639045.2012.662503] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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252
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Chen W, Tong YW. PHBV microspheres as neural tissue engineering scaffold support neuronal cell growth and axon-dendrite polarization. Acta Biomater 2012; 8:540-8. [PMID: 22005329 DOI: 10.1016/j.actbio.2011.09.026] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2011] [Revised: 08/26/2011] [Accepted: 09/20/2011] [Indexed: 11/19/2022]
Abstract
Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) microspheres, with properties such as slower degradation and more efficient drug delivery properties, have important benefits for neural tissue engineering. Our previous studies have shown PHBV microspheres to improve cell growth and differentiation. This study aimed to investigate if PHBV microspheres would support neurons to extend these benefits to neural tissue engineering. PHBV microspheres' suitability as neural tissue engineering scaffolds was investigated using PC12 cells, cortical neurons (CNs), and neural progenitor cells (NPCs) to cover a variety of neuronal types for different applications. Microspheres were fabricated using an emulsion-solvent-evaporation technique. DNA quantification, cell viability assays, and immunofluorescent staining were carried out. PC12 cultures on PHBV microspheres showed growth trends comparable to two-dimensional controls. This was further verified by staining for cell spreading. Also, CNs expressed components of the signaling pathway on PHBV microspheres, and had greater axon-dendrite segregation (4.1 times for axon stains and 2.3 times for dendrite stains) than on coverslips. NPCs were also found to differentiate into neurons on the microspheres. Overall, the results indicate that PHBV microspheres, as scaffolds for neural tissue engineering, supported a variety of neuronal cell types and promoted greater axon-dendrite segregation.
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Affiliation(s)
- Wenhui Chen
- NUS Graduate School for Integrative Sciences and Engineering, Department of Biomolecular and Chemical Engineering, National University of Singapore, Singapore
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253
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Modification of the release characteristics of estradiol encapsulated in PLGA particles via surface coating. Ther Deliv 2012; 3:209-26. [DOI: 10.4155/tde.11.154] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Background: Drug-loaded poly(lactide-co-glycolide) particles (100–4500 nm in diameter) were prepared via the electrospraying method. An extensive study was then carried out to determine the parameters affecting the release profile of estradiol (the drug or active pharmaceutical ingredient) in order to facilitate minimum initial burst release of estradiol. Results and discussion: The three most important factors affecting estradiol release were identified as: particle size, coating of the particles with chitosan/gelatin and the concentration of the coating agent. It was shown that coating the particles with chitosan significantly reduced the burst and initial release without affecting the subsequent release profile. Conclusions: This work demonstrates a powerful method of generating drug-loaded polymeric particles with modified release behavior and control over the initial release phase. The surface-modified particles may be useful in controlled therapeutic delivery systems to minimize undesirable side effects.
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254
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Wang NX, Bazdar DA, Sieg SF, von Recum HA. Microparticle delivery of Interleukin-7 to boost T-cell proliferation and survival. Biotechnol Bioeng 2012; 109:1835-43. [DOI: 10.1002/bit.24431] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 12/14/2011] [Accepted: 12/27/2011] [Indexed: 11/10/2022]
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255
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Lee WL, Widjaja E, Loo SCJ. Designing drug-loaded multi-layered polymeric microparticles. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2012; 23:81-88. [PMID: 22127404 DOI: 10.1007/s10856-011-4508-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Accepted: 11/18/2011] [Indexed: 05/31/2023]
Abstract
This work reports how novel multi-layered (from double-layered to quadruple-layered) microparticles comprising immiscible polymers can be fabricated through a simple, economical, reliable and versatile one-step solvent evaporation method. These multi-layered microparticles would be excellent candidates to overcome problems inherent in single-layered microparticles for drug delivery. Particle morphologies, layer configurations, and drug distribution were determined by scanning electron microscopy and Raman mapping. Key process parameters achieving the formation of the multi-layered structure were identified. Encapsulation of multiple drugs and layer localization of these drugs within these multi-layered microparticles have also shown to be possible, which were driven by drug-polymer affinity. This one-step fabrication technique can therefore be used for tailoring particle designs, thus facilitating the development of multiparticulate drug delivery devices.
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Affiliation(s)
- Wei Li Lee
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore
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256
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Biopolymer Particles for Proteins and Peptides Sustained Release Produced by Supercritical Emulsion Extraction. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.proeng.2012.07.415] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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257
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Micro- and Nano-Carrier Mediated Intra-Articular Drug Delivery Systems for the Treatment of Osteoarthritis. JOURNAL OF NANOTECHNOLOGY 2012. [DOI: 10.1155/2012/748909] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The objective of this paper is to provide readers with current developments of intra-articular drug delivery systems. In recent years, although the search for a clinically successful ideal carrier is ongoing, sustained-release systems, such as polymeric micro- and nanoparticles, liposomes, and hydrogels, are being extensively studied for intra-articular drug delivery purposes. The advantages associated with long-acting preparations include a longer effect of the drug in the action site and a reduced risk of infection due to numerous injections consequently. This paper discusses the recent developments in the field of intra-articular sustained-release delivery systems for the treatment of osteoarthritis.
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258
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Jadhav N, Bhakare H, Bhawale B. Incorporation of drug-resin complex to improve microsphere performance. ASIAN JOURNAL OF PHARMACEUTICS 2012. [DOI: 10.4103/0973-8398.100138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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259
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Khamanga SM, Walker RB. The use of response surface methodology in the evaluation of captopril microparticles manufactured using an oil in oil solvent evaporation technique. J Microencapsul 2011; 29:39-53. [DOI: 10.3109/02652048.2011.629744] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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260
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Kasliwal N, Negi JS, Jugran V, Jain R. Formulation, development, and performance evaluation of metoclopramide HCl oro-dispersible sustained release tablet. Arch Pharm Res 2011; 34:1691-700. [DOI: 10.1007/s12272-011-1013-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Revised: 04/17/2011] [Accepted: 06/21/2011] [Indexed: 11/30/2022]
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261
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Severino P, Santana MHA, Pinho SC, Souto EB. Polímeros sintéticos biodegradáveis: matérias-primas e métodos de produção de micropartículas para uso em drug delivery e liberação controlada. POLIMEROS 2011. [DOI: 10.1590/s0104-14282011005000060] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Micropartículas produzidas a partir de polímeros sintéticos têm sido amplamente utilizadas na área farmacêutica para encapsulação de princípios ativos. Essas micropartículas apresentam as vantagens de proteção do princípio ativo, mucoadesão e gastrorresistência, melhor biodisponibilidade e maior adesão do paciente ao tratamento. Além disso, utiliza menores quantidade de princípio ativo para obtenção do efeito terapêutico proporcionando diminuição dos efeitos adversos locais, sistêmicos e menor toxidade. Os polímeros sintéticos empregados na produção das micropartículas são classificados biodegradáveis ou não biodegradáveis, sendo os biodegradáveis mais utilizados por não necessitam ser removidos cirurgicamente após o término de sua ação. A produção das micropartículas poliméricas sintéticas para encapsulação tanto de ativos hidrofílicos quanto hidrofóbicos pode ser emulsificação por extração e/ou evaporação do solvente; coacervação; métodos mecânicos e estão revisados neste artigo evidenciando as vantagens, desvantagens e viabilidade de cada metodologia. A escolha da metodologia e do polímero sintético a serem empregados na produção desse sistema dependem da aplicação terapêutica requerida, bem como a simplicidade, reprodutibilidade e factibilidade do aumento de escala da produção.
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262
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Chang E, McClellan AJ, Farley WJ, Li DQ, Pflugfelder SC, De Paiva CS. Biodegradable PLGA-Based Drug Delivery Systems for Modulating Ocular Surface Disease under Experimental Murine Dry Eye. JOURNAL OF CLINICAL & EXPERIMENTAL OPHTHALMOLOGY 2011; 2:191. [PMID: 23560247 PMCID: PMC3614373 DOI: 10.4172/2155-9570.1000191] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE Continuous drug delivery to the ocular surface remains difficult due to the rapid tear clearance of topically applied agents. The purpose of this study was to evaluate biodegradable and biocompatible drug delivery systems on the ocular surface using poly-lactic-co-glycolic acid (PLGA) based polymers. METHODS Fluorescein-labeled albumin and doxycycline were individually encapsulated into a PLGA-based matrix using a water-oil-water double emulsion method. The drug elution rates for various microspheres were evaluated spectrofluorometrically. Particle size was measured using image analysis software. Subconjunctival injections of PLGA microspheres were used to evaluate safety and inflammatory response to the polymer in the murine model. Efficacy of the drug delivery system was evaluated by a single subconjunctival injection of PLGA-doxycycline (a broad metalloproteinase inhibitor) prior to induction of desiccating stress (DS) model in C57BL/6 mice for 5 days. RESULTS PLGA-based microspheres successfully elute encapsulated drugs of interest continuously over controlled periods of time. Mean PLGA-based microparticle diameter was 4.6 μm±1.54 μm. Drug elution rates and delivery times were easily modifiable by altering polymers and synthesis parameters. In vitro studies demonstrate successful continuous elution of encapsulated drugs for at least 2 weeks. In vivo testing of PLGA-doxycycline was efficacious in preventing DS-induced corneal barrier disruption with desiccating stress, similarly to topically applied doxycycline. CONCLUSIONS PLGA-based drug delivery systems are safe and non-inflammatory. They can be successfully used to treat ocular surface and corneal diseases by continuously delivering biopharmaceuticals of interest.
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Affiliation(s)
| | | | - William J. Farley
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA
| | - De-Quan Li
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA
| | - Stephen C. Pflugfelder
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA
| | - Cintia S. De Paiva
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA
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263
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Akagi T, Baba M, Akashi M. Biodegradable Nanoparticles as Vaccine Adjuvants and Delivery Systems: Regulation of Immune Responses by Nanoparticle-Based Vaccine. ADVANCES IN POLYMER SCIENCE 2011. [DOI: 10.1007/12_2011_150] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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264
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Yang Y, Gao Y, Mei X. Effects of formulation parameters on encapsulation efficiency and release behavior of thienorphine loaded PLGA microspheres. Pharm Dev Technol 2011; 18:1169-74. [DOI: 10.3109/10837450.2011.618948] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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265
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Porta GD, Campardelli R, Falco N, Reverchon E. PLGA microdevices for retinoids sustained release produced by supercritical emulsion extraction: Continuous versus batch operation layouts. J Pharm Sci 2011; 100:4357-67. [DOI: 10.1002/jps.22647] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Revised: 05/02/2011] [Accepted: 05/11/2011] [Indexed: 11/11/2022]
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266
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Enhanced encapsulation of metoprolol tartrate with carbon nanotubes as adsorbent. APPLIED NANOSCIENCE 2011. [DOI: 10.1007/s13204-011-0030-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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267
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Vay K, Scheler S, Frieß W. Application of Hansen solubility parameters for understanding and prediction of drug distribution in microspheres. Int J Pharm 2011; 416:202-9. [DOI: 10.1016/j.ijpharm.2011.06.047] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 06/22/2011] [Accepted: 06/24/2011] [Indexed: 11/27/2022]
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268
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Álvarez AL, Espinar FO, Méndez JB. The Application of Microencapsulation Techniques in the Treatment of Endodontic and Periodontal Diseases. Pharmaceutics 2011; 3:538-71. [PMID: 24310596 PMCID: PMC3857082 DOI: 10.3390/pharmaceutics3030538] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 08/09/2011] [Accepted: 08/24/2011] [Indexed: 11/12/2022] Open
Abstract
In the treatment of intracanal and periodontal infections, the local application of antibiotics and other therapeutic agents in the root canal or in periodontal pockets may be a promising approach to achieve sustained drug release, high antimicrobial activity and low systemic side effects. Microparticles made from biodegradable polymers have been reported to be an effective means of delivering antibacterial drugs in endodontic and periodontal therapy. The aim of this review article is to assess recent therapeutic strategies in which biocompatible microparticles are used for effective management of periodontal and endodontic diseases. In vitro and in vivo studies that have investigated the biocompatibility or efficacy of certain microparticle formulations and devices are presented. Future directions in the application of microencapsulation techniques in endodontic and periodontal therapies are discussed.
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Affiliation(s)
- Asteria Luzardo Álvarez
- Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Ciencias, Universidad de Santiago de Compostela, 27002 Lugo, Spain; E-Mail:
| | - Francisco Otero Espinar
- Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain; E-Mail:
| | - José Blanco Méndez
- Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Ciencias, Universidad de Santiago de Compostela, 27002 Lugo, Spain; E-Mail:
- Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain; E-Mail:
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269
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270
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Yu X, Pishko MV. Nanoparticle-based biocompatible and targeted drug delivery: characterization and in vitro studies. Biomacromolecules 2011; 12:3205-12. [PMID: 21786828 DOI: 10.1021/bm200681m] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Paclitaxel nanoparticles (PAX NPs) prepared with the size of 110 ± 10 nm and ζ potential of -40 ± 3 mV were encapsulated in synthetic/biomacromolecule shell chitosan, dextran-sulfate using a layer-by-layer self-assembly technique. Zeta potential measurements, analysis of X-ray photoelectron spectroscopy, and scanning electron microscopy confirmed the successful adsorption of each layer. Surface modifications of these core-shell NPs were performed by covalently conjugating with poly(ethylene glycol) (H(2)N-PEG-carboxymethyl, M(w) 3400) and fluorescence labeled wheat germ agglutinin (F-WGA) to build a biocompatible and targeted drug delivery system. 32% of PAX was released from four bilayers of biomacromolecule assembled NPs within 8 h as compared with >85% of the drug released from the bare NPs. Moreover, high cell viability with PEG conjugation and high binding capacity of WGA-modified NPs with Caco-2 cells were observed. This biocompatible and targeted NP-based drug delivery system, therefore, may be considered as a potential candidate for the treatment of colonic cancer and other diseases.
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Affiliation(s)
- Xiao Yu
- Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843-3122, United States
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271
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Zhang Z, Bi X, Li H, Huang G. Enhanced targeting efficiency of PLGA microspheres loaded with Lornoxicam for intra-articular administration. Drug Deliv 2011; 18:536-44. [DOI: 10.3109/10717544.2011.596584] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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272
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Malik K, Arora G, Singh I. Taste masked microspheres of ofloxacin: formulation and evaluation of orodispersible tablets. Sci Pharm 2011; 79:653-72. [PMID: 21886910 PMCID: PMC3163379 DOI: 10.3797/scipharm.1104-11] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Accepted: 07/21/2011] [Indexed: 11/22/2022] Open
Abstract
Ofloxacin is a synthetic chemotherapeutic antibiotic used for treatment of a variety of bacterial infections, but therapy suffers from low patients' compliance due to its unpleasant taste. This study was aimed to develop taste masked microspheres of ofloxacin using Eudragit and to prepare orodispersible tablets of the formulated microspheres using natural superdisintegrant. Taste masking Eudragit E100 microspheres were prepared by solvent evaporation technique with an entrapment efficiency ranging from 69.54 ± 1.98 to 86.52 ± 2.25%. DSC revealed no interaction between the drug and polymer. Microspheres prepared at a drug/polymer ratio of 1:4 and 1:5 revealed sufficient flow properties and better taste masking as compared to other ratios. Drug loaded microspheres were formulated as orodispersible tablets using locust bean gum as a natural superdisintegrant offering the advatages of biocompatibility and biodegrad-ability. The wetting time, water absorption ratio and in-vitro disintegration time of the tablets were found to range between 19 ± 2 to 10 ± 3 seconds, 59.11 ± 0.65 to 85.76 ± 0.96 and 22 ± 2 to 10 ± 2 seconds, respectively. The in-vitro ofloxacin release was about 97.25% within 2h. The results obtained from the study suggested the use of eudragit polymer for preparing ofloxacin loaded microspheres with an aim to mask the bitter taste of the drug and furthermore orodispersible tablets could be formulated using locust bean gum as a natural superdisintegrant.
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Affiliation(s)
- Karan Malik
- School of Pharmaceutical Sciences, Chitkara University, Solan-174103, Himachal Pradesh, India
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273
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Kotagale NR, Patel CJ, Parkhe AP, Khandelwal HM, Taksande JB, Umekar MJ. Carbopol 934-Sodium Alginate-Gelatin Mucoadhesive Ondansetron Tablets for Buccal Delivery: Effect of pH Modifiers. Indian J Pharm Sci 2011; 72:471-9. [PMID: 21218058 PMCID: PMC3013565 DOI: 10.4103/0250-474x.73912] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2010] [Revised: 07/09/2010] [Accepted: 07/28/2010] [Indexed: 11/25/2022] Open
Abstract
The present work aims at developing mucoahesive tablets of ondansetron hydrochloride using bioadhesive polymers like carbopol-934, sodium alginate and gelatin. Tablets prepared by direct compression using different polymer with varying ratio were evaluated for hardness, friability, uniformity of weight, disintegration time, microenvironmental pH, bioadhesion and in vitro release. Hardness, friability disintegration time and drug release were found within pharmacopoeial limit. Microenvironmental pH decreased whereas bioadhesive strength, water uptake, and in vitro release increased with increase in carbopol-934. Increasing sodium alginate and gelatin increased the microenviromental pH and decreased bioadhesive strength, water uptake and in vitro release. With a view to investigate the modulation of drug release from formulation by addition of pH modifiers viz. citric acid and sodium bicarbonate, the tablets with carbopol-934 (2.0), sodium alginate (0.5) and gelatin (6.5) were used and the effect of pH modifiers on microenvironmental pH, bioadhesion, water uptake, in vitro permeation and in vitro release was studied. Microenvironmental pH, bioadhesive strength, water uptake, in vitro release and permeation decreased with increasing concentration of citric acid whereas microenvironmental pH, water uptake and release were enhanced and bioadhesive strength was lowered with increase in sodium bicarbonate. Present study demonstrates carbopol-934, sodium alginate, gelatin polymer system with added pH modifier can be successfully formulated for buccal delivery of ondansetron with desired release profile.
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Affiliation(s)
- N R Kotagale
- Smt. Kishoritai Bhoyar College of Pharmacy, Behind Railway Station, New Kamptee, Dist. Nagpur, Maharashtra - 441 002, India
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274
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Chen YS, Alany RG, Young SA, Green CR, Rupenthal ID. In vitro release characteristics and cellular uptake of poly(D,L-lactic-co-glycolic acid) nanoparticles for topical delivery of antisense oligodeoxynucleotides. Drug Deliv 2011; 18:493-501. [PMID: 21696294 DOI: 10.3109/10717544.2011.589088] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The efficacy of antisense oligodeoxynucleotides (AsODNs) is compromised by their poor stability in biological fluids and the inefficient cellular uptake due to their size and negative charge. Since chemical modifications of these molecules have resulted in a number of non-antisense activities, incorporation into particulate delivery systems has offered a promising alternative. The aim of this study was to evaluate various poly(D,L-lactic-co-glycolic acid) (PLGA) nanoparticles for AsODN entrapment and delivery. PLGA nanoparticles were prepared using the double emulsion solvent evaporation method. The influence of formulation parameters such as PLGA concentration and volume ratio of internal aqueous phase volume (Va1) to organic phase volume (Vo) to external aqueous phase volume (Va2) on particle size, polydispersity index (PDI) and zeta potential (ZP) was investigated using a full factorial study. The particle size increased with increasing PLGA concentrations and volume ratios, with an interaction detectable between the two factors. AsODN entrapment efficiencies ranged between 49.97% and 54.95% with no significant difference between various formulations. By fitting the in vitro release profiles to a dual first order release model it was shown that the AsODN release occurred via two processes: a diffusion controlled process in the early phase (25 to 32% within one day) and a PLGA degradation process in the latter (39 to 70% after 14 days). Cellular uptake studies using primary corneal epithelial cells suggested active transport of nanoparticles via endocytosis. PLGA nanoparticles therefore show potential to successfully entrap AsODNs, transport them into cells and release them over time due to polymer erosion.
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Affiliation(s)
- Ying-Shan Chen
- Department of Ophthalmology, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
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275
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Lai SK, Suk JS, Pace A, Wang YY, Yang M, Mert O, Chen J, Kim J, Hanes J. Drug carrier nanoparticles that penetrate human chronic rhinosinusitis mucus. Biomaterials 2011; 32:6285-90. [PMID: 21665271 DOI: 10.1016/j.biomaterials.2011.05.008] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2011] [Accepted: 05/03/2011] [Indexed: 01/21/2023]
Abstract
No effective therapies currently exist for chronic rhinosinusitis (CRS), a persistent inflammatory condition characterized by the accumulation of highly viscoelastic mucus (CRSM) in the sinuses. Nanoparticle therapeutics offer promise for localized therapies for CRS, but must penetrate CRSM in order to avoid washout during sinus cleansing and to reach underlying epithelial cells. Prior research has not established whether nanoparticles can penetrate the tenacious CRSM barrier, or instead become trapped. Here, we first measured the diffusion rates of polystyrene nanoparticles and the same nanoparticles modified with muco-inert polyethylene glycol (PEG) coatings in fresh, minimally perturbed CRSM collected during endoscopic sinus surgery from CRS patients with and without nasal polyp. We found that uncoated polystyrene particles, previously shown to be mucoadhesive in a number of human mucus secretions, were immobilized in all CRSM samples tested. In contrast, densely PEGylated particles as large as 200 nm were able to readily penetrate all CRSM samples from patients with CRS alone, and nearly half of CRSM samples from patients with nasal polyp. Based on the mobility of different sized PEGylated particles, we estimated the average pore size of fresh CRSM to be at least 150 ± 50 nm. Guided by these studies, we formulated mucus-penetrating particles composed of poly(lactide-co-glycolide) (PLGA) and Pluronics, two materials with a long history of safety and use in humans. We showed that these biodegradable particles are capable of rapidly penetrating CRSM at average speeds up to only 20-fold slower than their theoretical speeds in water. Our findings strongly support the development of mucus-penetrating nanomedicines for the treatment of CRS.
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Affiliation(s)
- Samuel K Lai
- Department of Chemical & Biomolecular Engineering, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA.
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276
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Ito F, Kanakubo Y, Murakami Y. Rapid preparation of monodisperse biodegradable polymer nanospheres using a membrane emulsification technique under low gas pressure. JOURNAL OF POLYMER RESEARCH 2011. [DOI: 10.1007/s10965-011-9617-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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277
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Karal-Yılmaz O, Serhatlı M, Baysal K, Baysal BM. Preparation and in vitro characterization of vascular endothelial growth factor (VEGF)-loaded poly(D,L-lactic-co-glycolic acid) microspheres using a double emulsion/solvent evaporation technique. J Microencapsul 2011; 28:46-54. [PMID: 21171816 DOI: 10.3109/02652048.2010.523795] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Biodegradable Poly(lactic-co-glycolic acid; PLGA), microspheres encapsulating the angiogenic protein recombinant human vascular endothelial growth factor (rhVEGF) were formed to achieve VEGF release in a sustained manner. These microspheres are a promising delivery system which can be used for therapeutic angiogenesis. The PLGA microspheres incorporating two different initial loading amounts of rhVEGF have been prepared by a modified water-in-oil-in-water (w/o/w) double emulsion/solvent evaporation technique. The microspheres have been characterized by particle size distribution, environmental scanning electron microscopy (ESEM), light microscopy, encapsulation efficiency and their degradation was studied in vitro. The rhVEGF released from microspheres was quantified by the competitive enzyme-linked immunosorbent assay (ELISA) and human umbilical vein endothelial cell (HUVEC) proliferation assay was used to assess biological activity of the released VEGF. The microspheres were spherical with diameters of 10-60 µm and the encapsulation efficiency was between 46% and 60%. The release kinetics of rhVEGF was studied for two different amounts: 5 µg VEGF (V5) and 50 µg VEGF (V50) per 500 mg starting polymer. The total protein (VEGF:BSA) release increased up to 4 weeks for two rhVEGF concentrations. The ELISA results showed that the burst release for V5 and V50 microspheres were 4 and 27 ng/mL, respectively. For V5, the microspheres showed an initial burst release, followed by a higher steady-state release until 14 days. VEGF release increased up to 2 weeks for V50 microsphere. HUVEC proliferation assay showed that endothelial cells responded to bioactive VEGF by proliferating and migrating.
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Affiliation(s)
- Okşan Karal-Yılmaz
- TUBITAK, Marmara Research Center, Genetic Engineering and Biotechnology Institute, P.O. Box 21, 41470 Gebze-Kocaeli, Turkey.
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278
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Sander JS, Studart AR. Monodisperse functional colloidosomes with tailored nanoparticle shells. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:3301-7. [PMID: 21384846 DOI: 10.1021/la1035344] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
We report the assembly of monodisperse colloidosomes containing a wide range of functional nanoparticles in the outer shell using a double emulsion templating method in a microfluidic device. By selecting nanoparticles of specific functionalities, hollow capsules with inert, magnetic, photocatalytic, and potentially biocompatible and piezoelectric shells are easily obtained. Proper control over the surface chemistry of the nanoparticles forming the shell and of the liquid interfaces involved is key to enable the assembly of colloidosomes using this double emulsification route.
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Affiliation(s)
- J S Sander
- Complex Materials, Department of Materials, ETH Zurich, 8093, Zurich, Switzerland
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279
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Andreas K, Zehbe R, Kazubek M, Grzeschik K, Sternberg N, Bäumler H, Schubert H, Sittinger M, Ringe J. Biodegradable insulin-loaded PLGA microspheres fabricated by three different emulsification techniques: investigation for cartilage tissue engineering. Acta Biomater 2011; 7:1485-95. [PMID: 21168535 DOI: 10.1016/j.actbio.2010.12.014] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Revised: 11/17/2010] [Accepted: 12/13/2010] [Indexed: 01/02/2023]
Abstract
Growth, differentiation and migration factors facilitate the engineering of tissues but need to be administered with defined gradients over a prolonged period of time. In this study insulin as a growth factor for cartilage tissue engineering and a biodegradable PLGA delivery device were used. The aim was to investigate comparatively three different microencapsulation techniques, solid-in-oil-in-water (s/o/w), water-in-oil-in-water (w/o/w) and oil-in-oil-in-water (o/o/w), for the fabrication of insulin-loaded PLGA microspheres with regard to protein loading efficiency, release and degradation kinetics, biological activity of the released protein and phagocytosis of the microspheres. Insulin-loaded PLGA microspheres prepared by all three emulsification techniques had smooth and spherical surfaces with a negative zeta potential. The preparation technique did not affect particle degradation nor induce phagocytosis by human leukocytes. The delivery of structurally intact and biologically active insulin from the microspheres was shown using circular dichroism spectroscopy and a MCF7 cell-based proliferation assay. However, the insulin loading efficiency (w/o/w about 80%, s/o/w 60%, and o/o/w 25%) and the insulin release kinetics were influenced by the microencapsulation technique. The results demonstrate that the w/o/w microspheres are most appropriate, providing a high encapsulation efficiency and low initial burst release, and thus these were finally used for cartilage tissue engineering. Insulin released from w/o/w PLGA microspheres stimulated the formation of cartilage considerably in chondrocyte high density pellet cultures, as determined by increased secretion of proteoglycans and collagen type II. Our results should encourage further studies applying protein-loaded PLGA microspheres in combination with cell transplants or cell-free in situ tissue engineering implants to regenerate cartilage.
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Affiliation(s)
- Kristin Andreas
- Berlin-Brandenburg Center for Regenerative Therapies, Department of Rheumatology and Clinical Immunology, Charité-Universitätsmedizin Berlin, Berlin, Germany.
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280
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Encapsulation of water-soluble drugs by an o/o/o-solvent extraction microencapsulation method. Int J Pharm 2011; 409:89-95. [PMID: 21356287 DOI: 10.1016/j.ijpharm.2011.02.029] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Revised: 12/31/2010] [Accepted: 02/21/2011] [Indexed: 11/22/2022]
Abstract
A new o/o/o-solvent extraction microencapsulation method based on less toxic solvents is presented in this study. The drug is dissolved/dispersed into a poly(D,L-lactide)/or poly (D,L-lactide-co-glycolide) (PLGA) solution in a water-miscible organic solvent (e.g., dimethylsulfoxide or 2-pyrrolidone) (o(1)), followed by emulsification into an oil phase (o(2)) (e.g., peanut oil). This emulsion is added to the external phase (o(3)) to solidify the drug-containing polymer droplets. The polymer solvent and the oil are extracted in an external phase (o(3)) (e.g., ethanol), which is a nonsolvent for the polymer and miscible with both the polymer solvent and the oil. One major advantage of this method is the reduced amount of solvent/nonsolvent volumes. In addition, very high encapsulation efficiencies were achieved at polymer concentration of 20%, w/w for all investigated polymers and o(1)/o(2) phase ratios with ethanol as the external (o(3)) phase. The encapsulation efficiency was very low (<20%) with water as external phase. The particle size of the microparticles increased with increasing polymer concentration and o(1)/o(2) phase ratio and larger microparticles were obtained with 2-pyrrolidone compared to dimethylsulfoxide as polymer solvent (o(1)). After an initial burst, in vitro drug release from the microparticles increased for the investigated polymer as follows: Resomer(®) RG 506>RG 756>R 206. A third more rapid release phase was observed after 6 weeks with Resomer(®) RG 506 due to polymer degradation. Similar drug release patterns were obtained with the o/o/o and w/o/w multiple emulsion methods because of similar porous structures. This new method has the advantages of less toxic solvents, much lower preparation volume and solvent consumption and high encapsulation efficiencies when compared to the classical w/o/w method.
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281
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Wisuitiprot W, Somsiri A, Ingkaninan K, Waranuch N. A novel technique for chitosan microparticle preparation using a water/silicone emulsion: green tea model. Int J Cosmet Sci 2011; 33:351-8. [PMID: 21323933 DOI: 10.1111/j.1468-2494.2010.00635.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Many effective methods such as spray drying, coacervation, ionic gelation, solvent evaporation and sieving have been suggested for entrapping bioactive compounds into micro- or nanoparticles. However, those methods still have some limitations owing to high temperature requirement, difficulty in particle harvesting or low entrapment for uncharged molecules. In this study, a novel chitosan microparticle preparation method was developed using water-in-silicone emulsion technique with green tea extract as a model active compound. Chitosan microparticles of diameter <5 μm were obtained from 2% chitosan solution with tripolyphosphate (TPP) solution as the hardening agent. The size and properties of the particles appeared to depend on several parameters such as TPP, emulsifier concentrations and pH. High concentration of emulsifier led to low encapsulation and particle aggregation. Entrapment efficiency of chitosan microparticles was improved with lower pH of the tripolyphosphate solution [59.94 ± 3.97 of epigallocatechin gallate (EGCG)] while slowing release of catechins. Epigallocatechin and epicatechin were released almost completely within 2 h under acidic condition whereas EGCG and epicatechin gallate were slowly released. In neutral condition, release of catechins depended on their molecular stabilities. The stabilities of catechins loaded in chitosan microparticles were varied under various temperatures. The degradation of tea catechins increased with temperature. However, the degradation of tea catechins loaded in chitosan microparticles was less than that of free catechins. Thus, the new technique for preparing chitosan microparticles containing heat-sensitive water soluble green tea extract was successfully developed. The technique is suitable for micro-encapsulation of hydrophilic compounds into chitosan microparticles with the ease of harvesting technique.
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Affiliation(s)
- W Wisuitiprot
- Department of Pharmaceutical Technology and Department of Pharmacognosy and Pharmaceutical Chemistry, Naresuan University, Phitsanulok, Thailand
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282
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Cao H, Dong Y, O'Rorke S, Wang W, Pandit A. PEG based hyperbranched polymeric hollow nanospheres. NANOTECHNOLOGY 2011; 22:065604. [PMID: 21212483 DOI: 10.1088/0957-4484/22/6/065604] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The synthesis of a new PEG based hyperbranched copolymer of poly(ethylene glycol) methyl ether methacrylate-co-ethylene glycol dimethacrylate (PEGMEMA-co-EGDMA) was achieved via a one-step in situ deactivation enhanced atom transfer radical polymerization (DE-ATRP). Then, hollow PEG based nanospheres were fabricated from this polymer using a solvent evaporation method and post-stabilisation strategy. Furthermore, the analysis using a cellular metabolic activity assay proved that the copolymer did not affect cellular metabolism, indicating that this PEG based polymeric nanosphere has potential for use in drug delivery applications.
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Affiliation(s)
- Hongliang Cao
- Network of Excellence for Functional Biomaterials, National University of Ireland, Galway, Ireland
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283
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Synthesis of Temperature-Responsive Dextran-MA/PNIPAAm Particles for Controlled Drug Delivery Using Superhydrophobic Surfaces. Pharm Res 2011; 28:1294-305. [DOI: 10.1007/s11095-011-0380-2] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Accepted: 01/19/2011] [Indexed: 10/18/2022]
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284
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Luciani CV, Choi KY, Han JJ, Jung Y. Polymer particles with a pomegranate-like internal structure via micro-dispersive polymerization in a geometrically confined reaction space I. Experimental study. POLYMER 2011. [DOI: 10.1016/j.polymer.2010.12.055] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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285
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Shahani K, Panyam J. Highly loaded, sustained-release microparticles of curcumin for chemoprevention. J Pharm Sci 2011; 100:2599-609. [PMID: 21547911 DOI: 10.1002/jps.22475] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2010] [Revised: 12/04/2010] [Accepted: 12/14/2010] [Indexed: 12/15/2022]
Abstract
Curcumin, a dietary polyphenol, has preventive and therapeutic potential against several diseases. Because of the chronic nature of many of these diseases, sustained-release dosage forms of curcumin could be of significant clinical value. However, extreme lipophilicity and instability of curcumin are significant challenges in its formulation development. The objectives of this study were to fabricate an injectable microparticle formulation that can sustain curcumin release over a 1-month period and to determine its chemopreventive activity in a mouse model. Microparticles were fabricated using poly(D, L-lactide-co-glycolide) polymer. Conventional emulsion solvent evaporation method of preparing microparticles resulted in crystallization of curcumin outside of microparticles and poor entrapment (∼1%, w/w loading). Rapid solvent removal using vacuum dramatically increased drug entrapment (∼38%, w/w loading; 76% encapsulation efficiency). Microparticles sustained curcumin release over 4 weeks in vitro, and drug release rate could be modulated by varying the polymer molecular weight and/or composition. A single subcutaneous dose of microparticles sustained curcumin liver concentration for nearly a month in mice. Hepatic glutathione-s-transferase and cyclooxygenase-2 activities, biomarkers for chemoprevention, were altered following treatment with curcumin microparticles. The results of these studies suggest that sustained-release microparticles of curcumin could be a novel and effective approach for cancer chemoprevention.
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Affiliation(s)
- Komal Shahani
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan 48201, USA
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286
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Ajellal N, Thomas CM, Aubry T, Grohens Y, Carpentier JF. Encapsulation and controlled release of l-leuprolide from poly(β-hydroxyalkanoate)s: impact of microstructure and chemical functionalities. NEW J CHEM 2011. [DOI: 10.1039/c0nj00998a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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287
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Li Z, Wei X, Ngai T. Controlled production of polymer microspheres from microgel-stabilized high internal phase emulsions. Chem Commun (Camb) 2011; 47:331-3. [DOI: 10.1039/c0cc02106g] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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288
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Comparative study of preparation and characterization of enteric and enhanced release omeprazole microparticles. J Drug Deliv Sci Technol 2011. [DOI: 10.1016/s1773-2247(11)50079-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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289
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McDaniel JR, Callahan DJ, Chilkoti A. Drug delivery to solid tumors by elastin-like polypeptides. Adv Drug Deliv Rev 2010; 62:1456-67. [PMID: 20546809 PMCID: PMC2940962 DOI: 10.1016/j.addr.2010.05.004] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Revised: 05/11/2010] [Accepted: 05/13/2010] [Indexed: 01/08/2023]
Abstract
Thermally responsive elastin-like polypeptides (ELPs) are a promising class of recombinant biopolymers for the delivery of drugs and imaging agents to solid tumors via systemic or local administration. This article reviews four applications of ELPs to drug delivery, with each delivery mechanism designed to best exploit the relationship between the characteristic transition temperature (T(t)) of the ELP and body temperature (T(b)). First, when T(t)≫T(b), small hydrophobic drugs can be conjugated to the C-terminus of the ELP to impart the amphiphilicity needed to mediate the self-assembly of nanoparticles. These systemically delivered ELP-drug nanoparticles preferentially localize to the tumor site via the EPR effect, resulting in reduced toxicity and enhanced treatment efficacy. The remaining three approaches take direct advantage of the thermal responsiveness of ELPs. In the second strategy, where T(b)
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Affiliation(s)
- Jonathan R. McDaniel
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, 27708-0181, USA
| | - Daniel J. Callahan
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, 27708-0181, USA
| | - Ashutosh Chilkoti
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, 27708-0181, USA
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290
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Zhu AM, Hua Chen J, Liu QL, Jiang YL. Controlled release of berberine hydrochloride from alginate microspheres embedded within carboxymethyl chitosan hydrogels. J Appl Polym Sci 2010. [DOI: 10.1002/app.33433] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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291
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Binks BP, Fletcher PDI, Holt BL, Beaussoubre P, Wong K. Selective retardation of perfume oil evaporation from oil-in-water emulsions stabilized by either surfactant or nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:18024-18030. [PMID: 21067125 DOI: 10.1021/la103700g] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We have used dynamic headspace analysis to investigate the evaporation rates of perfume oils from stirred oil-in-water emulsions into a flowing gas stream. We compare the behavior of an oil of low water solubility (limonene) and one of high water solubility (benzyl acetate). It is shown how the evaporation of an oil of low water solubility is selectively retarded and how the retardation effect depends on the oil volume fraction in the emulsion. We compare how the evaporation retardation depends on the nature of the adsorbed film stabilizing the emulsion. Surfactant films are less effective than adsorbed films of nanoparticles, and the retardation can be further enhanced by compression of the adsorbed nanoparticle films by preshrinking the emulsion drops.
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Affiliation(s)
- Bernard P Binks
- Surfactant & Colloid Group, Department of Chemistry, University of Hull, Hull HU6 7RX, United Kingdom
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292
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Klose D, Delplace C, Siepmann J. Unintended potential impact of perfect sink conditions on PLGA degradation in microparticles. Int J Pharm 2010; 404:75-82. [PMID: 21056644 DOI: 10.1016/j.ijpharm.2010.10.054] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 10/27/2010] [Accepted: 10/30/2010] [Indexed: 01/03/2023]
Abstract
Yet, no standardized test method for drug release measurements from PLGA-based microparticles has been generally agreed on, or described by the regulatory authorities. Often, perfect sink conditions are provided in vitro to avoid artificial drug saturation effects. However, the maintenance of such conditions might strongly affect PLGA degradation. The involved physicochemical processes are complex and the potential impact of perfect sink conditions is not yet well understood. Differently sized, highly porous, carbamazepine- and ibuprofen-loaded PLGA microparticles were prepared by a W/O/W emulsion solvent extraction/evaporation technique. The initial drug loading was intentionally low (3-4%) so that the two drugs were molecularly dispersed within the polymeric matrices (monolithic solutions). This was important to be able to exclude potential limited drug solubility effects on the resulting release kinetics. Drug release into phosphate buffer pH 7.4 was measured under perfect sink conditions. SEC, DSC and SEM were used to characterize polymer degradation. The decrease in the average polymer molecular weight, glass transition temperature as well as changes in the inner and outer morphology of the PLGA microparticles were strongly affected by the bulk fluid's volume. In the case of the poorly water-soluble drug carbamazepine, much lower "microparticle mass:phosphate buffer volume" ratios were required to maintain perfect sink conditions, resulting in stable pH values within the bulk fluid, slower PLGA degradation and, thus, lower drug release rates. Thus, great care has to be taken when defining the conditions for in vitro drug release measurements from PLGA-based microparticles, avoiding potentially artificial conditions for polymer degradation.
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Affiliation(s)
- D Klose
- Univ Lille Nord de France, College of Pharmacy, 3 Rue du Prof Laguesse, 59006 Lille, France
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293
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Allhenn D, Lamprecht A. Microsphere Preparation Using the Untoxic Solvent Glycofurol. Pharm Res 2010; 28:563-71. [DOI: 10.1007/s11095-010-0304-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Accepted: 10/12/2010] [Indexed: 11/24/2022]
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294
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Luciani CV, Choi KY, Xiao Z. Inverse Free Radical Suspension Polymerization as a Potential Means to Encapsulate Biologically Active Materials. Chem Eng Technol 2010. [DOI: 10.1002/ceat.201000254] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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295
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Li R, Li X, Liu L, Zhou Z, Tang H, Zhang Q. High-Yield Fabrication of PLGA Non-Spherical Microarchitectures by Emulsion-Solvent Evaporation Method. Macromol Rapid Commun 2010; 31:1981-6. [DOI: 10.1002/marc.201000332] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Revised: 07/19/2010] [Indexed: 11/08/2022]
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296
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Al Helou M, Anjum N, Guedeau-Boudeville MA, Rosticher M, Mourchid A. Structure and mechanical properties of polylactide copolymer microspheres and capsules. POLYMER 2010. [DOI: 10.1016/j.polymer.2010.09.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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297
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Romero G, Estrela-Lopis I, Zhou J, Rojas E, Franco A, Espinel CS, Fernández AG, Gao C, Donath E, Moya SE. Surface engineered Poly(lactide-co-glycolide) nanoparticles for intracellular delivery: uptake and cytotoxicity--a confocal raman microscopic study. Biomacromolecules 2010; 11:2993-9. [PMID: 20882998 DOI: 10.1021/bm1007822] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Confocal Raman Microscopy (CRM) is used to study the cell internalization of poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) fabricated by emulsion techniques with either poly(ethylene imine) (PEI) or bovine serum albumin (BSA) as surface stabilizers. HepG2 cells were exposed to PEI and BSA stabilized PLGA NPs. Spontaneous Confocal Raman Spectra taken in one and the same spot of exposed cells showed bands arising from the cellular environment as well as bands characteristic for PLGA, proving that the PLGA NPs have been internalized. It was found that PLGA NPs preferentially colocalize with lipid bodies. The results from Raman spectroscopy are compared with flow cytometry and confocal scanning laser microscopy (CLSM) data. The advantages of CRM as a label-free technique over flow cytometry and CLSM are discussed. Additionally, cell viability studies by means of quick cell counting solution and MTT tests in several cell lines show a generally low toxicity for both PEI and BSA stabilized PLGA NPs, with BSA stabilized PLGA NPs having an even lower toxicity than PEI stabilized.
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Affiliation(s)
- Gabriela Romero
- CIC BiomaGUNE, Paseo Miramón 182 Ed. Emp. C, San Sebastián, Spain, Institute of Biophysics and Medical Physics, University of Leipzig, Leipzig, Germany, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China, and Laboratorio de Inmunología, Edificio Ciencias Experimentales, Campus Lagoas Marcosende, Universidad de Vigo, CP 36310, Vigo, Pontevedra, Spain
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298
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Lee J, Oh YJ, Lee SK, Lee KY. Facile control of porous structures of polymer microspheres using an osmotic agent for pulmonary delivery. J Control Release 2010; 146:61-7. [DOI: 10.1016/j.jconrel.2010.05.026] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Revised: 04/28/2010] [Accepted: 05/20/2010] [Indexed: 10/19/2022]
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299
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Camargo JA, Sapin A, Daloz D, Maincent P. Ivermectin-loaded microparticles for parenteral sustained release:in vitrocharacterization and effect of some formulation variables. J Microencapsul 2010; 27:609-17. [DOI: 10.3109/02652048.2010.501397] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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300
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Effect of PEGylation on stability of peptide in poly(lactide-co-glycolide) microspheres. Arch Pharm Res 2010; 33:1111-6. [DOI: 10.1007/s12272-010-0718-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Revised: 04/19/2010] [Accepted: 05/13/2010] [Indexed: 11/27/2022]
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