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Craciun G, Calina IC, Demeter M, Scarisoreanu A, Dumitru M, Manaila E. Poly(Acrylic Acid)-Sodium Alginate Superabsorbent Hydrogels Synthesized by Electron Beam Irradiation Part I: Impact of Initiator Concentration and Irradiation Dose on Structure, Network Parameters and Swelling Properties. MATERIALS (BASEL, SWITZERLAND) 2023; 16:4552. [PMID: 37444866 DOI: 10.3390/ma16134552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 06/16/2023] [Accepted: 06/20/2023] [Indexed: 07/15/2023]
Abstract
In the present paper, hydrogels based on acrylic acid (20%), sodium alginate (0.5%) and poly(ethylene oxide) (0.1%) were obtained by electron beam irradiation at room temperature with doses between 5 and 20 kGy, using potassium persulfate in concentrations up to 0.3% as a reaction initiator. The influence of initiator concentration and irradiation dose on hydrogel network parameters, swelling and deswelling behavior, gelation and degradation points, structure and morphology were investigated. Cross-link density increased with the irradiation dose and initiator addition, except at 20 kGy. The gel fraction was over 87.0% in all cases. Swelling experiments in distilled water showed swelling degrees of 40,000% at an irradiation dose of 5 kGy when a concentration of 0.1% initiator was added. A relationship between the swelling degree and irradiation dose, cross-linking degree (that increases from 0.044 × 102 to 0.995 × 102 mol/cm3) and mesh size (that decreases from about 220 nm to 26 nm) was observed. The addition of only 0.1% of PP led to the obtaining of hydrogels with a swelling degree of 42,954% (about 430 g/g) at an irradiation dose of 5 kGy and of 7206% (about 62 g/g) at 20 kGy, which are higher percentages than those obtained in the same irradiation conditions but without PP.
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Affiliation(s)
- Gabriela Craciun
- Electron Accelerators Laboratory, National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor St., 077125 Magurele, Romania
| | - Ion Cosmin Calina
- Electron Accelerators Laboratory, National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor St., 077125 Magurele, Romania
| | - Maria Demeter
- Electron Accelerators Laboratory, National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor St., 077125 Magurele, Romania
| | - Anca Scarisoreanu
- Electron Accelerators Laboratory, National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor St., 077125 Magurele, Romania
| | - Marius Dumitru
- Electron Accelerators Laboratory, National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor St., 077125 Magurele, Romania
| | - Elena Manaila
- Electron Accelerators Laboratory, National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor St., 077125 Magurele, Romania
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Popova EV, Morozova PV, Uspenskaya MV, Radilov AS. Sodium alginate and carbopol microcapsules: preparation, polyphenol encapsulation and release efficiency. Russ Chem Bull 2021. [DOI: 10.1007/s11172-021-3220-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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3
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Zhong H, Gao X, Cheng C, Liu C, Wang Q, Han X. The Structural Characteristics of Seaweed Polysaccharides and Their Application in Gel Drug Delivery Systems. Mar Drugs 2020; 18:658. [PMID: 33371266 PMCID: PMC7765921 DOI: 10.3390/md18120658] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 12/16/2020] [Accepted: 12/17/2020] [Indexed: 02/06/2023] Open
Abstract
In recent years, researchers across various fields have shown a keen interest in the exploitation of biocompatible natural polymer materials, especially the development and application of seaweed polysaccharides. Seaweed polysaccharides are a multi-component mixture composed of one or more monosaccharides, which have the functions of being anti-virus, anti-tumor, anti-mutation, anti-radiation and enhancing immunity. These biological activities allow them to be applied in various controllable and sustained anti-inflammatory and anticancer drug delivery systems, such as seaweed polysaccharide-based nanoparticles, microspheres and gels, etc. This review summarizes the advantages of alginic acid, carrageenan and other seaweed polysaccharides, and focuses on their application in gel drug delivery systems (such as nanogels, microgels and hydrogels). In addition, recent literature reports and applications of seaweed polysaccharides are also discussed.
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Affiliation(s)
| | | | - Cui Cheng
- College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, China; (H.Z.); (X.G.); (C.L.); (Q.W.)
| | | | | | - Xiao Han
- College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, China; (H.Z.); (X.G.); (C.L.); (Q.W.)
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Mutlu B, Farhan M, Kucuk I. T-Shaped Microfluidic Junction Processing of Porous Alginate-Based Films and Their Characteristics. Polymers (Basel) 2019; 11:E1386. [PMID: 31450763 PMCID: PMC6780642 DOI: 10.3390/polym11091386] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 08/15/2019] [Accepted: 08/20/2019] [Indexed: 02/07/2023] Open
Abstract
In this work, highly monodisperse porous alginate films from bubble bursting were formed on a glass substrate at ambient temperature, by a T-shaped microfluidic junction device method using polyethylene glycol (PEG) stearate and phospholipid as precursors in some cases. Various polymer solution concentrations and feeding liquid flow rates were applied for the generation of monodisperse microbubbles, followed by the conversion of the bubbles to porous film structures on glass substrates. In order to compare the physical properties of polymeric solutions, the effects of alginate, PEG stearate (surfactant), and phospholipid concentrations on the flowability of the liquid in a T-shaped microfluidic junction device were studied. To tailor microbubble diameter and size distribution, a method for controlling the thinning process of the bubbles' shell was also explored. In order to control pore size, shape, and surface as well as internal structure morphologies in the scalable forming of alginate polymeric films, the effect of the feeding liquid's flow rate and concentrations of PEG-stearate and phospholipid was also studied. Digital microscopy images revealed that the as-formed alginate films at the flow rate of 100 µL·min-1 and the N2 gas pressure of 0.8 bar have highly monodisperse microbubbles with a polydispersity index (PDI) of approximately 6.5%. SEM captures also revealed that the as-formed alginate films with high PDI value have similar monodisperse porous surface and internal structure morphologies, with the exception that the as-formed alginate films with the help of phospholipids were mainly formed under our experimental environment. From the Fourier-transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) measurements, we concluded that no chemical composition changes, thermal influence, and crystal structural modifications were observed due to the T-shaped microfluidic junction device technique. The method used in this work could expand and enhance the use of alginate porous films in a wide range of bioengineering applications, especially in tissue engineering and drug delivery, such as studying release behaviors to different internal and surface morphologies.
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Affiliation(s)
- Betul Mutlu
- Graduate School of Natural and Applied Sciences, Bursa Technical University, Bursa 16310, Turkey
| | - Muhammad Farhan
- Department of Pharmaceutics, Bahauddin Zakariya University, Multan 60800, Pakistan
| | - Israfil Kucuk
- Institute of Nanotechnology, Gebze Technical University, Gebze 41400, Turkey.
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Chen J, Tao N, Fang S, Chen Z, Liang L, Sun X, Li J, Liu YN. Incorporation of Fmoc-Y nanofibers into Ca-alginate hydrogels for improving their mechanical properties and the controlled release of small molecules. NEW J CHEM 2018. [DOI: 10.1039/c8nj00729b] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A robust interpenetrating network (IPN) hydrogel was assembled from calcium alginate and Fmoc-tyrosine for the controlled release of small molecules.
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Affiliation(s)
- Jiahui Chen
- College of Chemistry and Chemical Engineering
- Central South University
- Changsha
- P. R. China
| | - Na Tao
- College of Chemistry and Chemical Engineering
- Central South University
- Changsha
- P. R. China
| | - Shiqi Fang
- College of Chemistry and Chemical Engineering
- Central South University
- Changsha
- P. R. China
| | - Zewen Chen
- College of Chemistry and Chemical Engineering
- Central South University
- Changsha
- P. R. China
| | - Li Liang
- State Key Lab of Food Science and Technology
- School of Food Science and Technology
- Jiangnan University
- Wuxi
- P. R. China
| | - Xiaoyi Sun
- College of Chemistry and Chemical Engineering
- Central South University
- Changsha
- P. R. China
| | - Juan Li
- College of Chemistry and Chemical Engineering
- Central South University
- Changsha
- P. R. China
| | - You-Nian Liu
- College of Chemistry and Chemical Engineering
- Central South University
- Changsha
- P. R. China
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Liu CM, He XH, Liang RH, Liu W, Guo WL, Chen J. Relating physicochemical properties of alginate-HMP complexes to their performance as drug delivery systems. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2017; 28:2242-2254. [DOI: 10.1080/09205063.2017.1393176] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Cheng-mei Liu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
| | - Xiao-hong He
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
| | - Rui-hong Liang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
| | - Wei Liu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
| | - Wen-Li Guo
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
| | - Jun Chen
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
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Voo WP, Lee BB, Idris A, Islam A, Tey BT, Chan ES. Production of ultra-high concentration calcium alginate beads with prolonged dissolution profile. RSC Adv 2015. [DOI: 10.1039/c5ra03862f] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Ultra-high concentration (UHC) calcium alginate beads produced by temperature-controlled extrusion-dripping system show prolonged dissolution profile.
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Affiliation(s)
- Wan-Ping Voo
- Chemical Engineering Discipline
- School of Engineering
- Monash University Malaysia
- 46150 Bandar Sunway
- Malaysia
| | - Boon-Beng Lee
- School of Bioprocess Engineering
- Universiti Malaysia Perlis
- 02600 Arau
- Malaysia
| | - Ani Idris
- Department of Bioprocess Engineering
- Faculty of Chemical and Natural Resource Engineering
- Universiti Teknologi Malaysia
- 81310 Skudai
- Malaysia
| | - Aminul Islam
- Catalysis and Science Research Center
- Faculty of Science
- Universiti Putra Malaysia
- Malaysia
- Department of Chemistry
| | - Beng-Ti Tey
- Chemical Engineering Discipline
- School of Engineering
- Monash University Malaysia
- 46150 Bandar Sunway
- Malaysia
| | - Eng-Seng Chan
- Chemical Engineering Discipline
- School of Engineering
- Monash University Malaysia
- 46150 Bandar Sunway
- Malaysia
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8
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Overcoming therapeutic obstacles in inflammatory bowel diseases: A comprehensive review on novel drug delivery strategies. Eur J Pharm Sci 2013; 49:712-22. [DOI: 10.1016/j.ejps.2013.04.031] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2013] [Revised: 04/14/2013] [Accepted: 04/29/2013] [Indexed: 02/07/2023]
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9
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Mallikarjuna B, Madhusudana Rao K, Siraj S, Chandra Babu A, Chowdoji Rao K, Subha M. Sodium alginate/poly (ethylene oxide) blend hydrogel membranes for controlled release of valganciclovir hydrochloride. Des Monomers Polym 2012. [DOI: 10.1080/15685551.2012.705503] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Affiliation(s)
- B. Mallikarjuna
- a Department of Chemistry , Sri Krishnadevaraya University , Anantapur , Andhra Pradesh , India
| | - K. Madhusudana Rao
- a Department of Chemistry , Sri Krishnadevaraya University , Anantapur , Andhra Pradesh , India
| | - S. Siraj
- a Department of Chemistry , Sri Krishnadevaraya University , Anantapur , Andhra Pradesh , India
| | - A. Chandra Babu
- a Department of Chemistry , Sri Krishnadevaraya University , Anantapur , Andhra Pradesh , India
| | - K. Chowdoji Rao
- b Department of Polymer Science & Technology , Sri Krishnadevaraya University , Anantapur , Andhra Pradesh , India
| | - M.C.S. Subha
- a Department of Chemistry , Sri Krishnadevaraya University , Anantapur , Andhra Pradesh , India
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Nograles N, Abdullah S, Shamsudin MN, Billa N, Rosli R. Formation and characterization of pDNA-loaded alginate microspheres for oral administration in mice. J Biosci Bioeng 2012; 113:133-40. [DOI: 10.1016/j.jbiosc.2011.10.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 09/06/2011] [Accepted: 10/07/2011] [Indexed: 10/15/2022]
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11
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Swamy BY, Prasad CV, Reddy CLN, Sudhakara P, Chung I, Subha MCS, Chowdoji Rao K. Preparation of sodium alginate/poly(vinyl alcohol) blend microspheres for controlled release applications. J Appl Polym Sci 2011. [DOI: 10.1002/app.36243] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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12
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Ghosal K, Ray SD. Alginate/hydrophobic HPMC (60M) particulate systems: new matrix for site-specific and controlled drug delivery. BRAZ J PHARM SCI 2011. [DOI: 10.1590/s1984-82502011000400021] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study aimed to obtain site-specific and controlled drug release particulate systems. Some particulates were prepared using different concentrations of sodium alginate (Na-Alg) alone and others were formulated using different proportions of Na-Alg with hydroxypropyl methylcellulose (HPMC) stearoxy ether (60M viscosity grade), a hydrophobic form of conventional HPMC, using diclofenac potassium (DP) by ion-exchange methods. Beads were characterized by encapsulation efficiency, release profile, swelling, and erosion rate. The suitability of common empirical (zero-order, first-order and Higuchi) and semi-empirical (Ritger-Peppas and Peppas-Sahlin) models was studied to describe the drug release profile. The Weibull model was also studied. Models were tested by non-linear least-square curve fitting. A general purpose mathematical software (MATLAB) was used as an analysis tool. In addition, instead of the widely used linear fitting of log-transformed data, direct fitting was used to avoid any sort of truncation or transformation errors. The release kinetics of the beads indicated a purely relaxation-controlled delivery, referred to as case II transport. Weibull distribution showed a close fit. The release of DP from Na-Alg particulates was complete in 5-6 hours, whereas from Na-Alg hydrophobic HPMC particulate systems, release was sustained up to 10 hours. Hydrophobic HPMC with Na-Alg is an excellent matrix to formulate site-specific and controlled drug release particulate systems.
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Venkata Prasad C, Yerri Swamy B, Mallikarjuna B, Sreekanth KC, Subha MCS, Chowdoji Rao K, Yu JS. Preparation and characterization of interpenetrating polymer network beads for controlled release of acebutolol hydrochloride. ADVANCES IN POLYMER TECHNOLOGY 2011. [DOI: 10.1002/adv.20238] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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14
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Bautzová T, Rabišková M, Lamprecht A. Multiparticulate systems containing 5-aminosalicylic acid for the treatment of inflammatory bowel disease. Drug Dev Ind Pharm 2011; 37:1100-9. [DOI: 10.3109/03639045.2011.560156] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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15
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Bardajee GR, Pourjavadi A, Ghavami S, Soleyman R, Jafarpour F. UV-prepared salep-based nanoporous hydrogel for controlled release of tetracycline hydrochloride in colon. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2011; 102:232-40. [DOI: 10.1016/j.jphotobiol.2010.12.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Revised: 12/07/2010] [Accepted: 12/10/2010] [Indexed: 11/29/2022]
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16
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17
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Swamy TMM, Ramaraj B, Siddaramaiah. Sodium Alginate and Poly(ethylene glycol) Blends: Thermal and Morphological Behaviors. JOURNAL OF MACROMOLECULAR SCIENCE PART A-PURE AND APPLIED CHEMISTRY 2010. [DOI: 10.1080/10601325.2010.501296] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
| | - B. Ramaraj
- b Central Institute of Plastics Engineering and Technology , 437/A, Hebbal Industrial Area, Mysore, India
| | - Siddaramaiah
- c Department of Polymer Science and Technology , Sri Jayachamarajendra College of Engineering , Mysore, India
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18
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Philip AK, Philip B. Colon targeted drug delivery systems: a review on primary and novel approaches. Oman Med J 2010; 25:79-87. [PMID: 22125706 PMCID: PMC3215502 DOI: 10.5001/omj.2010.24] [Citation(s) in RCA: 170] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2010] [Accepted: 03/14/2010] [Indexed: 11/03/2022] Open
Abstract
The colon is a site where both local and systemic delivery of drugs can take place. Local delivery allows topical treatment of inflammatory bowel disease. However, treatment can be made effective if the drugs can be targeted directly into the colon, thereby reducing the systemic side effects. This review, mainly compares the primary approaches for CDDS (Colon Specific Drug Delivery) namely prodrugs, pH and time dependent systems, and microbially triggered systems, which achieved limited success and had limitations as compared with newer CDDS namely pressure controlled colonic delivery capsules, CODESTM, and osmotic controlled drug delivery which are unique in terms of achieving in vivo site specificity, and feasibility of manufacturing process.
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Affiliation(s)
- Anil K. Philip
- Department of Pharmaceutics, School of Pharmacy, University of Nizwa, Birkat Al Mouz, Nizwa-616, Sultanate of Oman
| | - Betty Philip
- Department of Pharmaceutics, School of Pharmacy, University of Nizwa, Birkat Al Mouz, Nizwa-616, Sultanate of Oman
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19
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Khoder M, Tsapis N, Fattal E. Mechanisms of antibiotic resistance and delivery strategies to prevent its emergence. J Drug Deliv Sci Technol 2010. [DOI: 10.1016/s1773-2247(10)50072-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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20
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Xiao J, Zhu Y, Liu Y, Zeng Y, Xu F. A composite coating of calcium alginate and gelatin particles on Ti6Al4V implant for the delivery of water soluble drug. J Biomed Mater Res B Appl Biomater 2009; 89:543-550. [PMID: 19048634 DOI: 10.1002/jbm.b.31246] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A composite coating on Ti6Al4V implant was prepared from alginate and gelatin particles through a dip-coating method to control the release of the water soluble drug gentamicin and improve the surface properties of the implant. Gentamicin was dissolved in the coating or bonded to gelatin particles through Schiff base reaction. The drug release experiments in vitro showed that about 10% of gentamicin was released within 0.5 h, the release lasted for 10 days, and the release from the composite coating was dependent on the pH value. The composite coating could induce the formation of apatite on the coating surface, which was fully covered after 7 days immersing in SBF solution. In addition, Ti6Al4V plate with the composite coating had excellent antibacterial activity against Staphylococcus aureus. All of the results provided the possibility that this composite coating might be applied as a controlled release system to deliver the water soluble drug, and as a bioactive, biodegradable layer on the bio-inert implant surface to induce the formation of apatite and actively bond to the surrounding tissue in vivo.
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Affiliation(s)
- Junwu Xiao
- Key Laboratory of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, China, 200050
| | - Yingchun Zhu
- Key Laboratory of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, China, 200050
| | - Yanyan Liu
- Key Laboratory of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, China, 200050
| | - Yi Zeng
- Key Laboratory of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, China, 200050
| | - Fangfang Xu
- Key Laboratory of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, China, 200050
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21
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Mruthyunjaya Swamy TM, Ramaraj B, Siddaramaiah. Thermal and morphological properties of SA/HPMC blends. J Appl Polym Sci 2009. [DOI: 10.1002/app.29738] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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22
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Danckwerts MP, van der Watt JG, Moodley I. Zero-Order Release of Theophylline from a Core-in-Cup Tablet in Sequenced Simulated Gastric and Intestinal Fluid. Drug Dev Ind Pharm 2008; 24:163-7. [PMID: 15605446 DOI: 10.3109/03639049809085601] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Core-in-cup tablets containing theophylline were evaluated for their dissolution characteristics in sequenced simulated gastric fluid (SGF) followed by simulated intestinalfluid (SIF). Core-in-cup tablets containing 10% w/w, 20% w/w, and 30% w/w acacia as binder were evaluated for their effects on the time course of release of theophylline. This was done to optimize a formula that could release theophylline at a zero-order rate of release for 8-16 hr in simulated gastrointestinal fluids. Theophylline was released and dissolved from the core-in-cup tablets at a rate that is more consistent with a zero-order dissolution rate than a first-order dissolution rate in both SIG and SIF. The dissolution rates of theophylline from the 10%, 20%, and 30% acacia core-in-cup tablets were 0.87 mg/min, 0.53 mg/min, and 0.27 mg/min, respectively in SGF, and 0.61 mg/min, 0.30 mg/min, and 0.20 mg/min, respectively in SIF. The results indicate that a concentration of 32% w/w acacia in the core tablet will release theophylline at a rate of 0.14 mg/min in SGF for 2 hr followed by SIF for 10 hr.
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Affiliation(s)
- M P Danckwerts
- Department of Pharmacy, Medical School, University of the Witwatersrand, 7 York Road, Parktown 2193, Johannesburg, Republic of South Africa
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Yegin BA, Moulari B, Durlu-Kandilci NT, Korkusuz P, Pellequer Y, Lamprecht A. Sulindac loaded alginate beads for a mucoprotective and controlled drug release. J Microencapsul 2008; 24:371-82. [PMID: 17497390 DOI: 10.1080/02652040701298153] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Ionotropic gelation was used to entrap sulindac into calcium alginate beads as a potential drug carrier for the oral delivery of this anti-inflammatory drug. Beads were investigated in vitro for a possible sustained drug release and their use in vivo as a gastroprotective system for sulindac. Process parameters such as the polymer concentration, polymer/drug ratio, and different needle diameter were analysed for their influences on the bead properties. Size augmented with increasing needle diameter (0.9 mm needle: 1.28 to 1.44 mm; 0.45 mm needle: 1.04 to 1.07 mm) due to changes in droplet size as well as droplet viscosity. Yields varied between 87% and 98% while sulindac encapsulation efficiencies of about 88% and 94% were slightly increasing with higher alginate concentrations. Drug release profiles exhibited a complete release for all formulations within 4 hours with a faster release for smaller beads. Sulindac loaded alginate beads led to a significant reduction of macroscopic histological damage in the stomach and duodenum in mice. Similarly, microscopic analyses of the mucosal damage demonstrated a significant mucoprotective effect of all bead formulation compared to the free drug. The present alginate formulations exhibit promising properties of a controlled release form for sulindac; meanwhile they provide a distinct tissue protection in the stomach and duodenum.
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Affiliation(s)
- Betül Arica Yegin
- Faculty of Pharmacy, Department of Pharmaceutical Technology, Hacettepe University, 06100 Sihhiye, Ankara, Turkey
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Sodium alginate and its blends with starch: Thermal and morphological properties. J Appl Polym Sci 2008. [DOI: 10.1002/app.28625] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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25
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Tapia C, Ormazabal V, Costa E, Yazdani-Pedram M. Study of dissolution behavior of matrices tablets based on alginate-gelatin mixtures as prolonged diltiazem hydrochloride release systems. Drug Dev Ind Pharm 2007; 33:585-93. [PMID: 17613023 DOI: 10.1080/03639040601085359] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The aim of this work was to develop prolonged diltiazem hydrochloride release matrices based on alginate-gelatin mixtures and establish the drug release mechanism. The erosion, swelling, and dissolution behavior of the tablets in different medium were evaluated. The different polyelectrolyte behavior and gel strength between type A Gelatin and type B Gelatin would explain the different swelling, erosion and dissolution behavior in the media with sudden pH change. The similar dissolution behavior in the pH, which simulates the physiological pH through the gastrointestinal tract, should be explained because the same main species for gelatin A and Gelatin B would be present in this media.
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Affiliation(s)
- Cristián Tapia
- Laboratory of Unit Operations, Faculty of Chemical and Pharmaceutical Sciences, University of Chile, Casilla, Santiago, Chile.
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Ramesh Babu V, Sairam M, Hosamani KM, Aminabhavi TM. Preparation of sodium alginate–methylcellulose blend microspheres for controlled release of nifedipine. Carbohydr Polym 2007. [DOI: 10.1016/j.carbpol.2006.09.027] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Al-Kassas RS, Al-Gohary OMN, Al-Faadhel MM. Controlling of systemic absorption of gliclazide through incorporation into alginate beads. Int J Pharm 2007; 341:230-7. [PMID: 17507189 DOI: 10.1016/j.ijpharm.2007.03.047] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2006] [Revised: 03/01/2007] [Accepted: 03/29/2007] [Indexed: 11/27/2022]
Abstract
This work investigates preparation of biodegradable beads with alginate polymer by ionotropic gelation method to take the advantages of the swelling and mucoadhesive properties of alginate beads for improving the oral delivery of the antidiabetic agent gliclazide. It demonstrates that the ionic gelation of alginate molecules offers a flexible and easily controllable process for manipulating the characteristics of the beads which are important in controlling the release rate and consequently the absorption of gliclazide from the gastrointestinal tract. Variations in polymer concentration, stirring speed, internal phase volume and the type of surfactant in the external phase were examined systemically for their effects on the particle size, incorporation efficiency and flow properties of the beads. The swelling behavior was strongly dependent on the polymer concentration in the formulations and the pH of the medium. The in vitro release experiments revealed that the swelling is the main parameter controlling the release rate of gliclazide from the beads. In vivo studies on diabetic rabbits showed that the hypoglycemic effect induced by the gliclazide loaded alginate beads was significantly greater and more prolonged than that induced by the marketed conventional gliclazide tablet (Gliclazide). The results clearly demonstrated the ability of the system to maintain tight blood glucose level and improved the patient compliance by enhancing, controlling and prolonging the systemic absorption of gliclazide.
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Affiliation(s)
- Raida S Al-Kassas
- Department of Pharmaceutics, College of Pharmacy, King Saud University, P.O. Box 17221, Riyadh 11484, Saudi Arabia.
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Chan LW, Liu X, Heng PWS. Liquid phase coating to produce controlled-release alginate microspheres. J Microencapsul 2006; 22:891-900. [PMID: 16423760 DOI: 10.1080/02652040500273936] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
This study explored a liquid phase coating technique to produce polymethyl methacrylate (PMMA)-coated alginate microspheres. Alginate microspheres with a mean diameter of 85.6 microm were prepared using an emulsification method. The alginate microspheres, as cores, were then coated with different types of PMMA by a liquid phase coating technique. The release characteristics of these coated microspheres in simulated gastric (SGF) and intestinal (SIF) fluids and the influence of drug load on encapsulation efficiency were studied. The release of paracetamol, as a model hydrophilic drug, from the coated microspheres in SGF and SIF was greatly retarded. Release rates of Eudragit RS100-coated microspheres in SGF and SIF were similar as the rate-controlling polymer coat was insoluble in both media. Drug release from Eudragit S100-coated microspheres was more sustained in SGF than in SIF, due to the greater solubility of the coating polymer in media with pH greater than 7.0. The drug release rate was affected by the core:coat ratio. Drug release from the coated microspheres was best described by the Higuchi's square root model. The liquid phase coating technique developed offers an efficient method of coating small microspheres with markedly reduced drug loss and possible controlled drug release.
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Affiliation(s)
- Lai Wah Chan
- Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore
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Krishna Rao KSV, Subha MCS, Vijaya Kumar Naidu B, Sairam M, Mallikarjuna NN, Aminabhavi TM. Controlled release of diclofenac sodium and ibuprofen through beads of sodium alginate and hydroxy ethyl cellulose blends. J Appl Polym Sci 2006. [DOI: 10.1002/app.25087] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Lamprecht A, Yamamoto H, Takeuchi H, Kawashima Y. pH-sensitive microsphere delivery increases oral bioavailability of calcitonin. J Control Release 2005; 98:1-9. [PMID: 15245884 DOI: 10.1016/j.jconrel.2004.02.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2003] [Accepted: 02/06/2004] [Indexed: 10/26/2022]
Abstract
Oral calcitonin (CT) administration is aimed in the treatment of calcemia in order to circumvent the required regular injections. CT containing microspheres (MS) were designed for colonic delivery by applying a pH-sensitive polymer Eudragit P-4135F for a double emulsion [water/oil/water (w/o/w)] microsphere preparation technique. CT was incorporated in the internal aqueous phase and carboxyfluorescein was encapsulated similarly to allow the characterization of the MS dissolution behavior. Eudragit P-4135F was found to keep the leakage of CT and carboxyfluorescein in vitro at pH 6.8 below 20% within 4 h while at pH 7.4, a fast release was observed for both, dye and peptide. Plasma levels of carboxyfluorescein after oral MS administration proved a sustained release in a rat model, where Cmax of carboxyfluorescein solution was found at around 60 min while for MS formulations it was detected after 4 h. At a dose of 20 microg CT/kg, no significant calcemic effects were found by MS formulations. However, increasing the dose to 100 microg CT/kg resulted in a distinct calcemia and revealed the sustained release properties of the MS. The relative pharmacological effect became most intense after 8-12 h based on the selective pH-dependent delivery. MS showed a fourfold increase of the area above the curve of calcium blood level compared to levels reached after CT solution. The coencapsulation of chitosan in the MS as absorption enhancer did not show any additional effect. The MS formulations proved their applicability as a promising device for pH-dependent colonic CT delivery and might be useful for other peptides.
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Affiliation(s)
- Alf Lamprecht
- Laboratory of Pharmaceutical Engineering, Pharmaceutical Engineering Department, Gifu Pharmaceutical University, 5-6-1 Mitahora Higashi, 502-8585, Japan
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Ramesh Babu V, Krishna Rao KSV, Sairam M, Naidu BVK, Hosamani KM, Aminabhavi TM. pH sensitive interpenetrating network microgels of sodium alginate-acrylic acid for the controlled release of ibuprofen. J Appl Polym Sci 2005. [DOI: 10.1002/app.22760] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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32
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Nokhodchi A, Tailor A. In situ cross-linking of sodium alginate with calcium and aluminum ions to sustain the release of theophylline from polymeric matrices. ACTA ACUST UNITED AC 2004; 59:999-1004. [PMID: 15598436 DOI: 10.1016/j.farmac.2004.08.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2004] [Accepted: 08/14/2004] [Indexed: 10/26/2022]
Abstract
Small matrices of calcium alginate or aluminium alginate have been investigated as possible controlled release systems for drugs. The objective of the present study was to sustain the release of theophylline from alginate matrices using different concentrations of aluminium chloride and calcium chloride in presence and absence of HPMC. Tablets containing differing concentrations of aluminium and calcium chloride were produced and the release rate of theophylline was tested using the basket dissolution apparatus over 8 h. Increasing amounts of aluminium chloride from 0.0001 to 0.00068 moles decreased the release of theophylline from 95.1 +/- 0.27 to 29.5 +/- 1.5, indicating a significant effect of aluminium ions on a reduction in the release rate of theophylline from sodium alginate matrices. In the case of matrices containing different concentrations of calcium ions, as the concentration of calcium chloride increased, the release rate increased to an optimum then declined after this. This was due to insufficient calcium ions being available to cross-link with the sodium alginate to form an insoluble gel. The effect of aluminium ions, as this is a trivalent ion compared to calcium, which is a divalent ion, aluminium ions are able to decrease the release rate with a smaller concentration compared to calcium ions. The results also showed that the presence of HPMC caused a reduction in release rate of theophylline from alginate matrices containing calcium chloride. Whereas, in the case of alginate matrices containing aluminium chloride the release rate of theophylline increased in presence of HPMC. For comparing the dissolution data, dissolution efficiency (DE) was used. The values of DE are consistent with the dissolution data. The results show that within a formulation series, DE values generally decrease when the cation concentration increases and this criterion can be used to describe the effect of calcium and aluminium ions on the release behaviour of theophylline from polymeric matrices.
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Affiliation(s)
- Ali Nokhodchi
- Pharmacy Department, Kings College London, 150 Stamford Street, Franklin-Wilkins Building, London SE1 9NN, UK.
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Lamprecht A, Yamamoto H, Takeuchi H, Kawashima Y. Design of pH-sensitive microspheres for the colonic delivery of the immunosuppressive drug tacrolimus. Eur J Pharm Biopharm 2004; 58:37-43. [PMID: 15207535 DOI: 10.1016/j.ejpb.2004.01.003] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2003] [Revised: 01/09/2004] [Accepted: 01/09/2004] [Indexed: 10/26/2022]
Abstract
Recently, tacrolimus was shown to be effective in mitigating inflammatory bowel disease (IBD). In the treatment of IBD, oral drug delivery using pH-dependent polymers is one of the most successful therapeutic strategies. Eudragit P-4135F, a pH-sensitive polymer for colonic delivery was used to prepare tacrolimus microparticles using an oil/oil emulsification or an oil/water emulsification technique combined with a solvent extraction or evaporation step. Although the pH-dependent drug release was similar for all types of microspheres, it was generally found that encapsulation rates of oil/water systems (extraction 38.8 +/- 9.4%; evaporation 56.3 +/- 1.9%) were superior to the oil/oil emulsification (4.8 +/- 0.4%). Eudragit P-4135F was found to limit drug leakage at pH 6.8 to levels lower than 10% within 6 h. At pH 7.4, almost immediate release (within 30 min) was observed. From differential scanning calorimetry and X-ray analyses, the drug inside the polymeric microsphere matrix was concluded to be present in a molecular dispersion. Generally, all formulations proved their applicability in vitro as a promising device for pH-dependent colonic delivery of tacrolimus, however, the oil/water technique was found to be superior to the oil/oil approach and among them solvent evaporation seemed to be more advisable, due to the higher encapsulation rate.
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Affiliation(s)
- Alf Lamprecht
- Laboratory of Pharmaceutical Engineering, Gifu Pharmaceutical University, Gifu, Japan
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Ferreira Almeida P, Almeida AJ. Cross-linked alginate–gelatine beads: a new matrix for controlled release of pindolol. J Control Release 2004; 97:431-9. [PMID: 15212875 DOI: 10.1016/j.jconrel.2004.03.015] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2004] [Accepted: 03/12/2004] [Indexed: 11/26/2022]
Abstract
This work is focused on the development of a new particulate drug delivery system using a sodium alginate matrix containing pindolol as a model drug molecule for intestinal drug prolonged release. Calcium alginate beads are known to be unable to control the release of most insoluble drugs. Pindolol-loaded alginate-gelatine beads have been developed using a solvent-free technique that involves a cross-linking reaction. Modifications in matrix structure and physicochemical behaviour caused by the cross-linking reaction were assessed during particle formation and drug release. Several parameters, such as matrix gelling rate, encapsulation efficiency, drug release profile and matrix erosion rate, were investigated. Physicochemical characterisation indicates the formation of a new alginate-gelatine matrix and shows that pindolol does not interfere with the matrix formation process. Matrix swelling of calcium alginate beads induced by phosphate buffer ends up in erosion and destruction. However, for cross-linked beads swelling does not lead to complete erosion, which may be the main cause of pindolol retention within the matrix. The modifications introduced in the initial calcium alginate formulation by means of an appropriate method such as the use of a cross-linking agent successfully changed the matrix performance, allowing the controlled release of pindolol.
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Affiliation(s)
- P Ferreira Almeida
- Unidade de Ciências e Tecnologia Farmacêuticas, Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisboa, Portugal
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Lamprecht A, Yamamoto H, Takeuchi H, Kawashima Y. Microsphere design for the colonic delivery of 5-fluorouracil. J Control Release 2003; 90:313-22. [PMID: 12880698 DOI: 10.1016/s0168-3659(03)00195-0] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The treatment of colon cancer has been aimed by approaches of oral drug administration. 5-Fluorouracil is the standard treatment still nowadays and would be a candidate to be delivered orally to the colon. A pH-sensitive polymer Eudragit P-4135F was used to prepare microspheres by a simple oil/water emulsification process. Process parameters were analyzed in order to optimize the drug loading and release profiles. In further attempts mixtures with Eudragit RS100 were prepared to prolong drug release. Scanning electron microscopy and confocal laser scanning microscopy permitted a structural analysis. The solvent extraction was preferable over solvent evaporation with a view to the encapsulation rate (extraction: 37%; evaporation: 19%) due to the hydrophilic character of the drug while release pattern were nearly unchanged. Eudragit P-4135F, pure or in mixture, was found to retain drug release at pH 6.8 lower than 35% within 6 h. At pH 7.4, nearly immediate release (within 30 min) was observed for pure P-4135F, while mixtures enabled to prolong the release slightly. Analysis of the morphology led to an inhomogeneous polymer distribution of P-4135F and RS100 throughout the particle core. A capsule-like structure was concluded which allowed only slight changes of the release kinetics by the addition of RS100. However, the formulation proved its applicability in-vitro as a promising device for pH-dependent colon delivery of 5-fluorouracil.
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Affiliation(s)
- Alf Lamprecht
- Laboratory of Pharmaceutical Engineering, Gifu Pharmaceutical University, 5-6-1 Mitahora Higashi, 502-8585 Gifu, Japan
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Abstract
Chitosan, a natural polymer obtained by alkaline deacetylation of chitin, is non-toxic, biocompatible, and biodegradable. These properties make chitosan a good candidate for the development of conventional and novel gastrointestinal (GI) drug and gene delivery systems. The objective of this review is to summarize the recent applications of chitosan in oral and/or buccal delivery, stomach-specific drug delivery, intestinal delivery, and colon-specific drug delivery. The use of chitosan for targeting of drugs to each of these sites in the GI tract is illustrated by examples supported by in vivo studies. Chitosan appears to be a promising material for GI drug and gene delivery applications as many derivatives and formulations are being examined.
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Affiliation(s)
- Radi Hejazi
- Department of Pharmaceutical Sciences, School of Pharmacy, Northeastern University, 110 Mugar Life Sciences Building, Boston, MA 02115, USA
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37
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Shilpa A, Agrawal SS, Ray AR. Controlled Delivery of Drugs from Alginate Matrix. ACTA ACUST UNITED AC 2003. [DOI: 10.1081/mc-120020160] [Citation(s) in RCA: 142] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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38
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Chan LW, Heng PWS. Effects of aldehydes and methods of cross-linking on properties of calcium alginate microspheres prepared by emulsification. Biomaterials 2002; 23:1319-26. [PMID: 11808537 DOI: 10.1016/s0142-9612(01)00250-2] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Calcium alginate microspheres were prepared by an emulsification method and cross-linked with various aldehydes using different methods. Methanal and pentanedial produced low aggregation of microspheres while octanal and octadecanal produced the opposite effect. The latter two aldehydes displaced very little calcium ions from the alginate microspheres, indicating that the aggregation was due to the tackiness imparted by the aldehydes to the microsphere surface. Higuchi's model was not applicable to the drug release from microspheres in this study. The microspheres treated with methanal or pentanedial showed comparable dissolution T75% values which were significantly higher than that of the control. In contrast, octanal and octadecanal produced microspheres with lower dissolution T75% values. The drug contents of the microspheres treated with aldehydes were significantly lower than that of the control. There was insignificant interaction between the aldehydes and the drug. However, the aldehydes were found to impart acidity to the aqueous solution to varying extents, resulting in varying drug loss from the microspheres. The properties of the microspheres were also markedly affected by the method of incorporating the aldehyde. Soaking the microspheres in methanal solution produced microspheres with marked aggregation and low drug content.
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Affiliation(s)
- Lai Wah Chan
- Department of Pharmacy, National University of Singapore
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Heng PW, Chan LW, Liew CV, Ng TY. Effect of tabletting compaction pressure on alginate microspheres. J Microencapsul 2000; 17:553-64. [PMID: 11038115 DOI: 10.1080/026520400417612] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Alginate and alginate-hydroxypropylmethylcellulose (HPMC) microspheres were prepared by the emulsification method. The compaction of microspheres for producing tablet dosage forms raises concerns about possible damage to microsphere walls with subsequent unpredictable dissolution rates. The effect of different compaction pressures on the integrity of the microspheres was investigated. The addition of a diluent, microcrystalline cellulose (MCC), was required to make compacts containing alginate and alginate-HPMC microspheres. Compacts containing alginate-HPMC (7:3) microspheres had the highest crushing strength followed by compacts containing alginate-HPMC (9:1) microspheres and alginate microspheres. However, compact crushing strength did not vary significantly with increased compaction pressures over the range of compaction pressures investigated. Differences in the drug release profiles of the original non-compacted and compacted alginate and alginate-HPMC microspheres were slight and not marked. Although dentation and distortion of the microspheres were observed with increasing compaction pressures, the microspheres generally remained intact, with minimal rupture/fracture.
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Affiliation(s)
- P W Heng
- Department of Pharmacy, National University of Singapore, Singapore.
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40
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Leopold CS. Coated dosage forms for colon-specific drug delivery. PHARMACEUTICAL SCIENCE & TECHNOLOGY TODAY 1999; 2:197-204. [PMID: 10322382 DOI: 10.1016/s1461-5347(99)00151-0] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Coating materials used in the manufacture of colon-specific solid oral dosage forms include polymers with a pH-dependent solubility that rely on the difference in pH between the small and the distal large intestine (pH-controlled release), polymers with a slow or pH-dependent rate of swelling, dissolution or erosion that take advantage of the constant small intestinal transit time (time-controlled release), polymers that are degradable by the microbial enzymes in the colon (enzyme-controlled release) and polymers that form firm layers that are destroyed by an increase of the luminal pressure in the colon caused by peristaltic waves (pressure-controlled release). This review gives an overview of coated dosage forms that have been developed to achieve colon specificity.
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Affiliation(s)
- CS Leopold
- Department of Pharmaceutical Technology, Heinrich Heine University, Universitätsstrasse 1, 40225 Düsseldorf, Germany
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41
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Lee BJ, Cui JH, Kim TW, Heo MY, Kim CK. Biphasic release characteristics of dual drug-loaded alginate beads. Arch Pharm Res 1998; 21:645-50. [PMID: 9868531 DOI: 10.1007/bf02976751] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The dual drug-loaded alginate beads simultaneously containing drug in inner and outer layers were prepared by dropping plain (single-layered) alginate beads into CaCl2 solution. The release characteristics were evaluated in simulated gastric fluid for 2 h followed by intestinal fluids thereafter for 12 h. The surface morphology and cross section of dual drug-loaded alginate beads was also investigated using scanning electron microscope (SEM). The poorly water-soluble ibuprofen was chosen as a model drug. The surface of single-layered and dual drug-loaded alginate beads showed very crude and roughness, showing aggregated particles, surface cracks and rough crystals. The thickness of dual drug-loaded alginate beads surrounded by outer layer was ranged from about 57 to 329 microns. The distinct chasm between inner and outer layers was also observed. In case of single-layered alginate beads, the drug was not released in gastric fluid but was largely released in intestinal fluid. However, the release rate decreased as the reinforcing Eudragit polymer contents increased. When the plasticizers were added into polymer, the release rate largely decreased. The release rate of dual drug-loaded alginate beads was stable in gastric fluid for 2 h but largely increased when switched in intestinal fluid. The drug linearly released for 4 h followed by another linear release thereafter, showing a distinct biphasic release characteristics. There was a difference in the release profiles between single-layered and dual drug-loaded alginate beads due to their structural shape. However, this biphasic release profiles were modified by varying formulation compositions of inner and outer layer of alginate beads. The release rate of dual drug-loaded alginate beads slightly decreased when the outer layer was reinforced with Eudragit RS100 polymers. In case of dual drug-loaded alginate beads with polymer-reinforced outer layer only, the initial amount of drug released was low but the initial release rate (slope) was higher due to more swellable inner cores when compared to polymer-reinforced inner cores. The current dual drug-loaded alginate beads may be used to deliver the drugs in a time dependent manner.
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Affiliation(s)
- B J Lee
- Biological Rhythm and Controlled Release Lab., College of Pharmacy, Kangwon National University, Chuncheon, Korea
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42
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Fundueanu G, Esposito E, Mihai D, Carpov A, Desbrieres J, Rinaudo M, Nastruzzi C. Preparation and characterization of Ca-alginate microspheres by a new emulsification method. Int J Pharm 1998. [DOI: 10.1016/s0378-5173(98)00063-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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43
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Chan LW, Heng PW. Effects of poly(vinylpyrrolidone) and ethylcellulose on alginate microspheres prepared by emulsification. J Microencapsul 1998; 15:409-20. [PMID: 9651863 DOI: 10.3109/02652049809006868] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Calcium alginate microspheres were prepared by an emulsification process. The effects of two co-polymers, namely poly(vinylpyrrolidone) and ethylcellulose, on the properties of the microspheres were studied. Microspheres prepared with and without poly(vinylpyrrolidone) were spherical and discrete. The microspheres containing poly(vinylpyrrolidone) exhibited a better flow property but the drug content was lower and the drug release rate higher. The method of incorporating poly(vinylpyrrolidone) was found to (significantly) affect the size distribution and drug content of the microspheres. Ethylcellulose produced marked aggregation of the microspheres which also showed a lower drug content, but a slower drug release. The retardation in drug release was attributed to the formation of aggregated microspheres with a less permeable matrix. The addition of triethyl citrate, which is a water-soluble plasticizer, was found to increase the rate of drug release while the use of a higher viscosity grade of ethylcellulose produced the opposite effect. Ethylcellulose improved the flowability of the microspheres to a greater extent than poly(vinylpyrrolidone).
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Affiliation(s)
- L W Chan
- Department of Pharmacy, National University of Singapore, Kent Ridge Crescent, Singapore
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Chan LW, Heng PW, Wan LS. Effect of cellulose derivatives on alginate microspheres prepared by emulsification. J Microencapsul 1997; 14:545-55. [PMID: 9292431 DOI: 10.3109/02652049709006808] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Generally discrete and spherical calcium alginate microspheres with a high drug encapsulation efficiency were readily prepared by an emulsification process. They were found to release drug rapidly. In the present study, co-polymer in the form of cellulose derivatives was added to sodium alginate in an attempt to modify the drug release profiles of the microspheres. The effects of cellulose derivatives on the morphology and drug encapsulation efficiency of the microspheres were also evaluated. The cellulose derivatives increased the degree of agglomeration of the microspheres. Small and spherical microspheres were produced from cellulose derivatives of low viscosity while larger microspheres which tended to be elongated were produced from cellulose derivatives of high viscosity. The drug encapsulation efficiency and the drug release profiles were influenced by the chemical nature of the cellulose derivative as well as its viscosity. The efficiency of drug encapsulation generally increased while the rate of drug release decreased with increasing viscosity of the cellulose derivatives. Less hydrophilic cellulose derivatives such as methyl cellulose and hydroxypropylmethyl cellulose were found to increase the efficiency of encapsulating sulphaguanidine, while more hydrophilic cellulose derivatives such as hydroxypropyl cellulose and carboxymethyl cellulose had the opposite effect. Among the cellulose derivatives used, only hydroxypropyl cellulose retarded the drug release of the microspheres.
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Affiliation(s)
- L W Chan
- Department of Pharmacy, National University of Singapore, Singapore
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45
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Aslani P, Kennedy RA. Effect of gelation conditions and dissolution media on the release of paracetamol from alginate gel beads. J Microencapsul 1996; 13:601-14. [PMID: 8864996 DOI: 10.3109/02652049609026044] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Paracetamol was entrapped in alginate beads gelled with calcium or zinc at 0.1, 0.34 or 0.7M. The payloads were of the order of 60-70% w/w which represented an entrapment yield of > 75%. The release of drug from the beads was observed in three media; water, Simulated Gastric Fluid USP without pepsin (SGF) and 0.1% trisodium citrate solution. Release was slowest in water and was complete within 4-5 h. The zinc beads released more slowly than calcium beads prepared at the same molar concentration of cation. Complete release of drug from the alginate gel beads in SGF occurred within 2 h and was unaffected by the cation type and concentration. Except for beads prepared from 0.1M zinc, paracetamol was released rapidly in the citrate solution. All release profiles could be described by first-order kinetics with half-lives which ranged from 25-73 min. Due to the rapid release in acidic conditions, it is unlikely that alginate beads loaded with a relatively water soluble drug will provide satisfactory prolonged release orally.
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Affiliation(s)
- P Aslani
- Pharmacy Department, University of Sydney, New South Wales, Australia
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Morgan SM, Al-Shamkhani A, Callant D, Schacht E, Woodley JF, Duncan R. Alginates as drug carriers: covalent attachment of alginates to therapeutic agents containing primary amine groups. Int J Pharm 1995. [DOI: 10.1016/0378-5173(95)00059-r] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Preparation and release characteristics of polymer-reinforced and coated alginate beads. Arch Pharm Res 1995. [DOI: 10.1007/bf02979193] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Abstract
Delivery of 5-aminosalicylic acid to the colon by sulphasalazine, other azo-bonded compounds and controlled-release preparations is introduced in the context of metabolism by epithelial cells and therapeutic efficacy in ulcerative colitis. Potential modes of action are then reviewed, including actions on luminal bacteria, epithelial cell surface receptors, cellular events (such as nitric oxide release or butyrate oxidation), electrolyte transport and epithelial permeability. Evidence for an influence of salicylates on circulating and lamina propria inflammatory cells is presented, as well as actions on adhesion molecules, chemotactic peptides and inflammatory mediators, such as eicosanoids, platelet-activating factor, cytokines or reactive oxygen metabolites. The precise mechanism will remain uncertain as long as the aetiology of ulcerative colitis is unknown, but a pluripotential mode of action of salicylates is an advantage when influencing the network of events that constitute chronic inflammation.
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Affiliation(s)
- S P Travis
- Gastroenterology Unit, Derriford Hospital, Plymouth, U.K
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Travis SP, Jewell DP. Salicylates for inflammatory bowel disease. BAILLIERE'S CLINICAL GASTROENTEROLOGY 1994; 8:203-31. [PMID: 7949456 DOI: 10.1016/0950-3528(94)90002-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Targeted delivery of 5-aminosalicylic acid to the small intestine and colon by controlled-release or azo-bonded compounds potentially offers treatment for ileal Crohn's disease as well as ulcerative colitis. The pharmacokinetics of sulphasalazine and aminosalicylate derivatives have been discussed and potential modes of action reviewed. These include actions on epithelial cell-surface receptors, cellular events and barrier function. Evidence for an influence of salicylates on circulating and tissue inflammatory cells is presented, as well as actions on adhesion molecules, chemotactic peptides, eicosanoids, cytokines and reactive oxygen metabolites. The precise mechanism remains unknown, but a pluripotential mode of action is an advantage when influencing the network of events that constitutes chronic inflammation. Controlled clinical trials of salicylates in ulcerative colitis and Crohn's disease have been reviewed. Their main role remains as maintenance therapy for ulcerative colitis, but relatively high doses of controlled-release preparations benefit patients with ileal Crohn's disease, following resection, or those who have recently relapsed. Finally, issues of clinical relevance have been addressed, including the choice of salicylate and safety, indications for initiating therapy, dose and duration of treatment, role in managing refractory colitis and future developments.
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