Preparation and Characterization of Electrospun Pectin-Based Films and Their Application in Sustainable Aroma Barrier Multilayer Packaging

[EN] Featured Application: The present study aims to develop novel pectin-based films by electrospinning. The here -prepared films were applied as aroma barrier interlayers between two biopolymer films to develop fully bio-based and biodegradable food packaging articles according to the principles of the Circular Economy. Pectin was first dissolved in distilled water and blended with low contents of polyethylene oxide 2000 (PEO2000) as the carrier polymer to produce electrospun fibers. The electrospinning of the water solution of pectin at 9.5 wt% containing 0.5 wt% PEO2000 was selected as it successfully resulted in continuous and non-defected ultrathin fibers with the highest pectin content. However, annealing of the resultant pectin-based fibers, tested at different conditions, developed films with low mechanical integrity, high porosity, and also dark color due to their poor thermal stability. Then, to improve the film-forming process of the electrospun mats, two plasticizers, namely glycerol and polyethylene glycol 900 (PEG(900)), were added to the selected pectin solution in the 2-3 wt% range. The optimal annealing conditions were found at 150 degrees C with a pressure of 12 kN load for 1 min when applied to the electrospun pectin mats containing 5 wt% PEO2000 and 30 wt% glycerol and washed previously with dichloromethane. This process led to completely homogenous films with low porosity and high transparency due to a phenomenon of fibers coalescence. Finally, the selected electrospun pectin-based film was applied as an interlayer between two external layers of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) by the electrospinning coating technology and the whole structure was annealed to produce a fully bio-based and biodegradable multilayer film with enhanced barrier performance to water vapor and limonene.This study was supported by the Turkish Scientific and Technological Research Council (TUBITAK) 2214-A International Research Fellowship Programme for PhD Students and by the Spanish Ministry of Science, Innovation, and Universities (MICIU) project numbers AGL2015-63855-C2-1-R. S.T.-G. is a recipient of a Juan de la Cierva¿Incorporación contract (IJCI-2016-29675) from MICIU.Balik, BA.; Argin, S.; Lagaron, JM.; Torres-Giner, S. (2019). Preparation and Characterization of Electrospun Pectin-Based Films and Their Application in Sustainable Aroma Barrier Multilayer Packaging. Applied Sciences. 9(23):1-24. https://doi.org/10.3390/app9235136S124923Ridley, B. L., O’Neill, M. A., & Mohnen, D. (2001). Pectins: structure, biosynthesis, and oligogalacturonide-related signaling. Phytochemistry, 57(6), 929-967. doi:10.1016/s0031-9422(01)00113-3Mukhiddinov, Z. (2000). Isolation and structural characterization of a pectin homo and ramnogalacturonan. Talanta, 53(1), 171-176. doi:10.1016/s0039-9140(00)00456-2MOHNEN, D. (2008). Pectin structure and biosynthesis. Current Opinion in Plant Biology, 11(3), 266-277. doi:10.1016/j.pbi.2008.03.006Naqash, F., Masoodi, F. A., Rather, S. A., Wani, S. M., & Gani, A. (2017). Emerging concepts in the nutraceutical and functional properties of pectin—A Review. Carbohydrate Polymers, 168, 227-239. doi:10.1016/j.carbpol.2017.03.058Noreen, A., Nazli, Z.-H., Akram, J., Rasul, I., Mansha, A., Yaqoob, N., … Zia, K. M. (2017). Pectins functionalized biomaterials; a new viable approach for biomedical applications: A review. International Journal of Biological Macromolecules, 101, 254-272. doi:10.1016/j.ijbiomac.2017.03.029Bernhardt, D. C., Pérez, C. D., Fissore, E. N., De’Nobili, M. D., & Rojas, A. M. (2017). Pectin-based composite film: Effect of corn husk fiber concentration on their properties. Carbohydrate Polymers, 164, 13-22. doi:10.1016/j.carbpol.2017.01.031Yu, W.-X., Wang, Z.-W., Hu, C.-Y., & Wang, L. (2014). Properties of low methoxyl pectin-carboxymethyl cellulose based on montmorillonite nanocomposite films. International Journal of Food Science & Technology, 49(12), 2592-2601. doi:10.1111/ijfs.12590Silva, M. A. da, Bierhalz, A. C. K., & Kieckbusch, T. G. (2009). Alginate and pectin composite films crosslinked with Ca2+ ions: Effect of the plasticizer concentration. Carbohydrate Polymers, 77(4), 736-742. doi:10.1016/j.carbpol.2009.02.014Jantrawut, P., Chaiwarit, T., Jantanasakulwong, K., Brachais, C., & Chambin, O. (2017). Effect of Plasticizer Type on Tensile Property and In Vitro Indomethacin Release of Thin Films Based on Low-Methoxyl Pectin. Polymers, 9(12), 289. doi:10.3390/polym9070289Chaiwarit, T., Ruksiriwanich, W., Jantanasakulwong, K., & Jantrawut, P. (2018). Use of Orange Oil Loaded Pectin Films as Antibacterial Material for Food Packaging. Polymers, 10(10), 1144. doi:10.3390/polym10101144Ma, X., Chang, P. R., Yu, J., & Stumborg, M. (2009). Properties of biodegradable citric acid-modified granular starch/thermoplastic pea starch composites. Carbohydrate Polymers, 75(1), 1-8. doi:10.1016/j.carbpol.2008.05.020ARGIN, S., & GÜLERİM, M. (2019). Development of antimicrobial gelatin films with boron derivatives. TURKISH JOURNAL OF BIOLOGY, 43(1), 47-57. doi:10.3906/biy-1807-181Kowalczyk, D., & Baraniak, B. (2011). Effects of plasticizers, pH and heating of film-forming solution on the properties of pea protein isolate films. Journal of Food Engineering, 105(2), 295-305. doi:10.1016/j.jfoodeng.2011.02.037Kowalczyk, D., Gustaw, W., Świeca, M., & Baraniak, B. (2013). A Study on the Mechanical Properties of Pea Protein Isolate Films. Journal of Food Processing and Preservation, 38(4), 1726-1736. doi:10.1111/jfpp.12135Talja, R. A., Helén, H., Roos, Y. H., & Jouppila, K. (2007). Effect of various polyols and polyol contents on physical and mechanical properties of potato starch-based films. Carbohydrate Polymers, 67(3), 288-295. doi:10.1016/j.carbpol.2006.05.019Vieira, M. G. A., da Silva, M. A., dos Santos, L. O., & Beppu, M. M. (2011). Natural-based plasticizers and biopolymer films: A review. European Polymer Journal, 47(3), 254-263. doi:10.1016/j.eurpolymj.2010.12.011Sanyang, M. L., Sapuan, S. M., Jawaid, M., Ishak, M. R., & Sahari, J. (2015). Effect of plasticizer type and concentration on physical properties of biodegradable films based on sugar palm (arenga pinnata) starch for food packaging. Journal of Food Science and Technology, 53(1), 326-336. doi:10.1007/s13197-015-2009-7Pavlath, A. E., Voisin, A., & Robertson, G. H. (1999). Pectin-based biodegradable water insoluble films. Macromolecular Symposia, 140(1), 107-113. doi:10.1002/masy.19991400112Penhasi, A., & Meidan, V. M. (2014). Preparation and characterization of in situ ionic cross-linked pectin films: Unique biodegradable polymers. Carbohydrate Polymers, 102, 254-260. doi:10.1016/j.carbpol.2013.11.042Lorevice, M. V., Otoni, C. G., Moura, M. R. de, & Mattoso, L. H. C. (2016). Chitosan nanoparticles on the improvement of thermal, barrier, and mechanical properties of high- and low-methyl pectin films. Food Hydrocolloids, 52, 732-740. doi:10.1016/j.foodhyd.2015.08.003Martelli, M. R., Barros, T. T., de Moura, M. R., Mattoso, L. H. C., & Assis, O. B. G. (2012). Effect of Chitosan Nanoparticles and Pectin Content on Mechanical Properties and Water Vapor Permeability of Banana Puree Films. Journal of Food Science, 78(1), N98-N104. doi:10.1111/j.1750-3841.2012.03006.xChaichi, M., Hashemi, M., Badii, F., & Mohammadi, A. (2017). Preparation and characterization of a novel bionanocomposite edible film based on pectin and crystalline nanocellulose. Carbohydrate Polymers, 157, 167-175. doi:10.1016/j.carbpol.2016.09.062Šešlija, S., Nešić, A., Škorić, M. L., Krušić, M. K., Santagata, G., & Malinconico, M. (2018). Pectin/Carboxymethylcellulose Films as a Potential Food Packaging Material. Macromolecular Symposia, 378(1), 1600163. doi:10.1002/masy.201600163Pasini Cabello, S. D., Takara, E. A., Marchese, J., & Ochoa, N. A. (2015). Influence of plasticizers in pectin films: Microstructural changes. Materials Chemistry and Physics, 162, 491-497. doi:10.1016/j.matchemphys.2015.06.019Espitia, P. J. P., Du, W.-X., Avena-Bustillos, R. de J., Soares, N. de F. F., & McHugh, T. H. (2014). Edible films from pectin: Physical-mechanical and antimicrobial properties - A review. Food Hydrocolloids, 35, 287-296. doi:10.1016/j.foodhyd.2013.06.005Bhardwaj, N., & Kundu, S. C. (2010). Electrospinning: A fascinating fiber fabrication technique. Biotechnology Advances, 28(3), 325-347. doi:10.1016/j.biotechadv.2010.01.004Torres-Giner, S., Wilkanowicz, S., Melendez-Rodriguez, B., & Lagaron, J. M. (2017). Nanoencapsulation of Aloe vera in Synthetic and Naturally Occurring Polymers by Electrohydrodynamic Processing of Interest in Food Technology and Bioactive Packaging. Journal of Agricultural and Food Chemistry, 65(22), 4439-4448. doi:10.1021/acs.jafc.7b01393Torres-Giner, S., Pérez-Masiá, R., & Lagaron, J. M. (2016). A review on electrospun polymer nanostructures as advanced bioactive platforms. Polymer Engineering & Science, 56(5), 500-527. doi:10.1002/pen.24274Frenot, A., & Chronakis, I. S. (2003). Polymer nanofibers assembled by electrospinning. Current Opinion in Colloid & Interface Science, 8(1), 64-75. doi:10.1016/s1359-0294(03)00004-9Kim, J., & Reneker, D. H. (1999). Mechanical properties of composites using ultrafine electrospun fibers. Polymer Composites, 20(1), 124-131. doi:10.1002/pc.10340Furlan, R., Rosado, J. A. M., Rodriguez, G. G., Fachini, E. R., da Silva, A. N. R., & da Silva, M. L. P. (2012). Formation and Characterization of Oriented Micro- and Nanofibers Containing Poly (ethylene oxide) and Pectin. Journal of The Electrochemical Society, 159(3), K66-K71. doi:10.1149/2.057203jesLiu, S.-C., Li, R., Tomasula, P. M., Sousa, A. M. M., & Liu, L. (2016). Electrospun Food-Grade Ultrafine Fibers from Pectin and Pullulan Blends. Food and Nutrition Sciences, 07(07), 636-646. doi:10.4236/fns.2016.77065Cui, S., Yao, B., Sun, X., Hu, J., Zhou, Y., & Liu, Y. (2016). Reducing the content of carrier polymer in pectin nanofibers by electrospinning at low loading followed with selective washing. Materials Science and Engineering: C, 59, 885-893. doi:10.1016/j.msec.2015.10.086Cui, S.-S., Sun, X., Yao, B., Peng, X.-X., Zhang, X.-T., Zhou, Y.-F., … Liu, Y.-C. (2017). Size-Tunable Low Molecular Weight Pectin-Based Electrospun Nanofibers Blended with Low Content of Poly(ethylene oxide). Journal of Nanoscience and Nanotechnology, 17(1), 681-689. doi:10.1166/jnn.2017.12540McCune, D., Guo, X., Shi, T., Stealey, S., Antrobus, R., Kaltchev, M., … Zhang, W. (2018). Electrospinning pectin-based nanofibers: a parametric and cross-linker study. Applied Nanoscience, 8(1-2), 33-40. doi:10.1007/s13204-018-0649-4Chen, S., Cui, S., Zhang, H., Pei, X., Hu, J., Zhou, Y., & Liu, Y. (2018). Cross-Linked Pectin Nanofibers with Enhanced Cell Adhesion. Biomacromolecules, 19(2), 490-498. doi:10.1021/acs.biomac.7b01605Li, K., Cui, S., Hu, J., Zhou, Y., & Liu, Y. (2018). Crosslinked pectin nanofibers with well-dispersed Ag nanoparticles: Preparation and characterization. Carbohydrate Polymers, 199, 68-74. doi:10.1016/j.carbpol.2018.07.013Rockwell, P. L., Kiechel, M. A., Atchison, J. S., Toth, L. J., & Schauer, C. L. (2014). Various-sourced pectin and polyethylene oxide electrospun fibers. Carbohydrate Polymers, 107, 110-118. doi:10.1016/j.carbpol.2014.02.026Akinalan Balik, B., & Argin, S. (2019). Role of rheology on the formation of Nanofibers from pectin and polyethylene oxide blends. Journal of Applied Polymer Science, 137(3), 48294. doi:10.1002/app.48294Alborzi, S., Lim, L.-T., & Kakuda, Y. (2010). Electrospinning of Sodium Alginate-Pectin Ultrafine Fibers. Journal of Food Science, 75(1), C100-C107. doi:10.1111/j.1750-3841.2009.01437.xCherpinski, A., Torres-Giner, S., Cabedo, L., & Lagaron, J. M. (2017). Post-processing optimization of electrospun submicron poly(3-hydroxybutyrate) fibers to obtain continuous films of interest in food packaging applications. Food Additives & Contaminants: Part A, 34(10), 1817-1830. doi:10.1080/19440049.2017.1355115Cherpinski, A., Torres-Giner, S., Vartiainen, J., Peresin, M. S., Lahtinen, P., & Lagaron, J. M. (2018). Improving the water resistance of nanocellulose-based films with polyhydroxyalkanoates processed by the electrospinning coating technique. Cellulose, 25(2), 1291-1307. doi:10.1007/s10570-018-1648-zMelendez-Rodriguez, B., Castro-Mayorga, J. L., Reis, M. A. M., Sammon, C., Cabedo, L., Torres-Giner, S., & Lagaron, J. M. (2018). Preparation and Characterization of Electrospun Food Biopackaging Films of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Derived From Fruit Pulp Biowaste. Frontiers in Sustainable Food Systems, 2. doi:10.3389/fsufs.2018.00038Melendez-Rodriguez, B., Figueroa-Lopez, K. J., Bernardos, A., Martínez-Máñez, R., Cabedo, L., Torres-Giner, S., & Lagaron, J. M. (2019). Electrospun Antimicrobial Films of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Containing Eugenol Essential Oil Encapsulated in Mesoporous Silica Nanoparticles. Nanomaterials, 9(2), 227. doi:10.3390/nano9020227Figueroa-Lopez, K. J., Vicente, A. A., Reis, M. A. M., Torres-Giner, S., & Lagaron, J. M. (2019). Antimicrobial and Antioxidant Performance of Various Essential Oils and Natural Extracts and Their Incorporation into Biowaste Derived Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Layers Made from Electrospun Ultrathin Fibers. Nanomaterials, 9(2), 144. doi:10.3390/nano9020144Quiles-Carrillo, L., Montanes, N., Lagaron, J., Balart, R., & Torres-Giner, S. (2019). Bioactive Multilayer Polylactide Films with Controlled Release Capacity of Gallic Acid Accomplished by Incorporating Electrospun Nanostructured Coatings and Interlayers. Applied Sciences, 9(3), 533. doi:10.3390/app9030533Agüero, A., Morcillo, M. del C., Quiles-Carrillo, L., Balart, R., Boronat, T., Lascano, D., … Fenollar, O. (2019). Study of the Influence of the Reprocessing Cycles on the Final Properties of Polylactide Pieces Obtained by Injection Molding. Polymers, 11(12), 1908. doi:10.3390/polym11121908Ralet, M.-C., Crépeau, M.-J., Buchholt, H.-C., & Thibault, J.-F. (2003). Polyelectrolyte behaviour and calcium binding properties of sugar beet pectins differing in their degrees of methylation and acetylation. Biochemical Engineering Journal, 16(2), 191-201. doi:10.1016/s1369-703x(03)00037-8Bizarria, M. T. M., d’ Ávila, M. A., & Mei, L. H. I. (2014). Non-woven nanofiber chitosan/peo membranes obtained by electrospinning. Brazilian Journal of Chemical Engineering, 31(1), 57-68. doi:10.1590/s0104-66322014000100007Einhorn-Stoll, U., Kunzek, H., & Dongowski, G. (2007). Thermal analysis of chemically and mechanically modified pectins. Food Hydrocolloids, 21(7), 1101-1112. doi:10.1016/j.foodhyd.2006.08.004Godeck, R., Kunzek, H., & Kabbert, R. (2001). Thermal analysis of plant cell wall materials depending on the chemical structure and pre-treatment prior to drying. European Food Research and Technology, 213(4-5), 395-404. doi:10.1007/s002170100388Kastner, H., Einhorn-Stoll, U., & Senge, B. (2012). Structure formation in sugar containing pectin gels – Influence of Ca2+ on the gelation of low-methoxylated pectin at acidic pH. Food Hydrocolloids, 27(1), 42-49. doi:10.1016/j.foodhyd.2011.09.001Nisar, T., Wang, Z.-C., Yang, X., Tian, Y., Iqbal, M., & Guo, Y. (2018). Characterization of citrus pectin films integrated with clove bud essential oil: Physical, thermal, barrier, antioxidant and antibacterial properties. International Journal of Biological Macromolecules, 106, 670-680. doi:10.1016/j.ijbiomac.2017.08.068BUREN, J. P. (1979). THE CHEMISTRY OF TEXTURE IN FRUITS AND VEGETABLES. Journal of Texture Studies, 10(1), 1-23. doi:10.1111/j.1745-4603.1979.tb01305.xSila, D. N., Smout, C., Elliot, F., Loey, A. V., & Hendrickx, M. (2006). Non-enzymatic Depolymerization of Carrot Pectin: Toward a Better Understanding of Carrot Texture During Thermal Processing. Journal of Food Science, 71(1), E1-E9. doi:10.1111/j.1365-2621.2006.tb12391.xDiaz, J. V., Anthon, G. E., & Barrett, D. M. (2007). Nonenzymatic Degradation of Citrus Pectin and Pectate during Prolonged Heating:  Effects of pH, Temperature, and Degree of Methyl Esterification. Journal of Agricultural and Food Chemistry, 55(13), 5131-5136. doi:10.1021/jf0701483Krall, S. M., & McFeeters, R. F. (1998). Pectin Hydrolysis:  Effect of Temperature, Degree of Methylation, pH, and Calcium on Hydrolysis Rates. Journal of Agricultural and Food Chemistry, 46(4), 1311-1315. doi:10.1021/jf970473yRodrigo, D., Cortés, C., Clynen, E., Schoofs, L., Loey, A. V., & Hendrickx, M. (2006). Thermal and high-pressure stability of purified polygalacturonase and pectinmethylesterase from four different tomato processing varieties. Food Research International, 39(4), 440-448. doi:10.1016/j.foodres.2005.09.007Aburto, J., Moran, M., Galano, A., & Torres-García, E. (2015). Non-isothermal pyrolysis of pectin: A thermochemical and kinetic approach. Journal of Analytical and Applied Pyrolysis, 112, 94-104. doi:10.1016/j.jaap.2015.02.012Dick, M., Costa, T. M. H., Gomaa, A., Subirade, M., Rios, A. de O., & Flôres, S. H. (2015). Edible film production from chia seed mucilage: Effect of glycerol concentration on its physicochemical and mechanical properties. Carbohydrate Polymers, 130, 198-205. doi:10.1016/j.carbpol.2015.05.040Mishra, R. K., Anis, A., Mondal, S., Dutt, M., & Banthia, A. K. (2009). REPARATION AND CHARACTERIZATION OF AMIDATED PECTIN BASED POLYMER ELECTROLYTE MEMBRANES. Chinese Journal of Polymer Science, 27(05), 639. doi:10.1142/s0256767909004333Villanova, J. C. O., Ayres, E., & Oréfice, R. L. (2015). Design, characterization and preliminary in vitro evaluation of a mucoadhesive polymer based on modified pectin and acrylic monomers with potential use as a pharmaceutical excipient. Carbohydrate Polymers, 121, 372-381. doi:10.1016/j.carbpol.2014.12.052Basiak, E., Lenart, A., & Debeaufort, F. (2018). How Glycerol and Water Contents Affect the Structural and Functional Properties of Starch-Based Edible Films. Polymers, 10(4), 412. doi:10.3390/polym10040412Gondaliya, N., Kanchan, D. K., Sharma, P., & Joge, P. (2011). Structural and Conductivity Studies of Poly(Ethylene Oxide) – Silver Triflate Polymer Electrolyte System. Materials Sciences and Applications, 02(11), 1639-1643. doi:10.4236/msa.2011.211218Sanchez-Garcia, M. D., Gimenez, E., & Lagaron, J. M. (2008). Morphology and barrier properties of solvent cast composites of thermoplastic biopolymers and purified cellulose fibers. Carbohydrate Polymers, 71(2), 235-244. doi:10.1016/j.carbpol.2007.05.041Fabra, M. J., Lopez-Rubio, A., & Lagaron, J. M. (2014). Nanostructured interlayers of zein to improve the barrier properties of high barrier polyhydroxyalkanoates and other polyesters. Journal of Food Engineering, 127, 1-9. doi:10.1016/j.jfoodeng.2013.11.02

Oblikovanje i vrednovanje plutajućih uljnih mikrozrnaca loratadina s produljenim zadržavanjem u želucu

Gastro retentive controlled release system of loratadine was formulated to increase the residence time in stomach and to modulate the release behaviour of the drug. Oil entrapped floating microbeads prepared by emulsion gelation method were optimized by 23 factorial design and a polymer ratio of 2.5:1.5 (pectin: sodium alginate) by mass, 15% (m/v) of oil (mineral oil or castor oil) and 0.45 mol L-1 calcium chloride solution were selected as the optimized processing conditions for the desired buoyancy and physical stability. In vitro drug release in fed state conditions demonstrated sustained release of loratadine for 8 h that best fitted the Peppas model with n < 0.45. The ethylcellulose coating on microbeads optimized by 22 factorial design resulted in controlled release formulation of loratadine that provided zero-order release for 8 h.U radu je opisana priprava plutajućih mikrozrnaca za kontrolirano oslobađanje loratadina metodom želiranja emulzije. Mikrozrnca sadrže ulja, a njihovo zadržavanje u želucu je produljeno. Priprava mikrozrnaca je optimirana 23 faktorijalnim dizajnom. Pripravci optimalne sposobnosti plutanja i stabilnosti dobiveni su uz omjer masa pektina i natrijevog alginata 2,5:1,5, udio mineralnog ulja ili ulja kastora 15% (m/v) i koncentraciju kalcijevog klorida 0,45 mol L1. Iz tih se mikrozrnaca loratadin oslobađa in vitro tijekom 8 h, a oslobađanje slijedi Peppasov model ako je n < 0,45. Mikrozrnca presvučena etilcelulozom optimirana 22 faktorijalnim dizajnom slijede kinetiku nultog reda tijekom 8 h

Evaluation of in vitro wound adhesion characteristics of composite film and wafer based dressings using texture analysis and FTIR spectroscopy: A chemometrics factor analysis approach

The adhesive properties of two dressing types, solvent cast films and freeze-dried wafers have been determined and compared using two analytical techniques, combined with chemometrics data analysis.Films and wafers were prepared from gels containing polyox (POL) combined with carrageenan (CAR) or sodium alginate (SA), glycerol (GLY) as plasticiser (films) with streptomycin and diclofenac as model drugs. The gels were dried in an oven at 40°C or freeze-dried to obtain films and wafers respectively. The adhesive performance of the films and wafers was assessed with 6.67% w/v gel using a texture analyser to measure the stickiness, work of adhesion and cohesiveness. The effect of viscosity of simulated wound fluid[(containing (2% w/w or 5% w/w bovine serum albumin)] and mucin solution (2% w/w) present on the gelatin surface on texture analyser profiles was investigated. Furthermore, the adhesive properties were estimated and evaluated using attenuated total reflectance Fourier transform infrared spectroscopy by monitoring the diffusion of mucin solution [2% w/w in phosphate buffered saline (PBS) pH 7.4] through the formulations. The diffusion data was analysed using target factor analysis (chemometrics approach) to establish proof of concept for predicting adhesion by measuring mucin interaction and its diffusion through films and wafers. There was a significant effect of simulated wound fluid, viscosity, plasticizer (for films) and drug loading on the adhesive performance of both films and wafers. POL-SA films showed higher mucoadhesive performance in the presence of viscous simulated wound fluid containing 5% bovine serum albumin. Wafers and plasticised films demonstrated high detachment force indicating strong interactions between the chains of the polymers (POL, SA and CAR) and the model wound surface (gelatin). ATR-FTIR spectroscopy showed that mucin diffused independently through the solvent and across the films and wafers. POL-CAR films generally showed slower diffusion of mucin when compared with POL-SA films whilst the opposite effect was observed for diffusion through POL-CAR wafers and POL-SA wafers. Generally, diffusion through wafers was faster than the corresponding films

Direct Compression Behavior of Low- and High-Methoxylated Pectins

The objective of this study was to evaluate possible usefulness of pectins for direct compression of tablets. The deformation behavior of pectin grades of different degree of methoxylation (DM), namely, 5%, 10%, 25%, 35%, 40%, 50%, and 60% were, examined in terms of yield pressures (YP) derived from Heckel profiles for both compression and decompression and measurements of elastic recovery after ejection. All pectin grades showed a high degree of elastic recovery. DM 60% exhibited most plastic deformation (YP 70.4 MPa) whereas DM 5% (104.6 MPa) and DM 10% (114.7 MPa) least. However, DM 60% gave no coherent tablets, whereas tablet tensile strengths for DM 5% and DM 10% were comparable to Starch 1500®. Also, Heckel profiles were similar to Starch 1500®. For sieved fractions (180–250 and 90–125 μm) of DM 25% and DM 40% originating from the very same batch, YPs were alike, indicating minor effects of particle size. These facts indicate that DM is important for the compaction behavior, and batch-to-batch variability should also be considered. Therefore, pectins of low degree of methoxylation may have a potential as direct compression excipients

Chitosan Based Polyelectrolyte Complexes as Potential Carrier Materials in Drug Delivery Systems

Chitosan has been the subject of interest for its use as a polymeric drug carrier material in dosage form design due to its appealing properties such as biocompatibility, biodegradability, low toxicity and relatively low production cost from abundant natural sources. However, one drawback of using this natural polysaccharide in modified release dosage forms for oral administration is its fast dissolution rate in the stomach. Since chitosan is positively charged at low pH values (below its pKa value), it spontaneously associates with negatively charged polyions in solution to form polyelectrolyte complexes. These chitosan based polyelectrolyte complexes exhibit favourable physicochemical properties with preservation of chitosan’s biocompatible characteristics. These complexes are therefore good candidate excipient materials for the design of different types of dosage forms. It is the aim of this review to describe complexation of chitosan with selected natural and synthetic polyanions and to indicate some of the factors that influence the formation and stability of these polyelectrolyte complexes. Furthermore, recent investigations into the use of these complexes as excipients in drug delivery systems such as nano- and microparticles, beads, fibers, sponges and matrix type tablets are briefly described

Biological evaluation of alginate-based hydrogels, with antimicrobial features by Ce(III) incorporation, as vehicles for a bone substitute

In this work three different hydrogels were developed to associate, as vehicles, with the synthetic bone substitute GR-HA. One based on an alginate matrix (Alg); a second on a mixture of alginate and chitosan (Alg/Ch); and a third on alginate and hyaluronate (Alg/HA), using Ca2+ ions as cross-linking agents. The hydrogels, as well as the respective injectable bone substitutes (IBSs), were fully characterized from the physical-chemical point of view. Weight change studies proved that all hydrogels were able to swell and degrade within 72 hours at pH 7.4 and 4.0, being Alg/HA the hydrogel with the highest degradation rate (80%). Rheology studies demonstrated that all hydrogels are non-Newtonian viscoelastic fluids, and injectability tests showed that IBSs presented low maximum extrusion forces, as well as quite stable average forces. In conclusion, the studied hydrogels present the necessary features to be successfully used as vehicles of GR-HA, particularly the hydrogel Alg/HA.The authors would like to acknowledge the financial support from FCT (Fundacao para a Ciencia e a Tecnologia) through the grant SFRH/BD/76237/2011 and project ENMED/0002/2010, from FEDER funds through the program COMPETE-Programa Operacional Factores de Competitividade-under the project PEst-C/EME/UI0285/2011, as well as to the project I&DT BIOMAT&CELL n. 1372

Evaluation of sesamum gum as an excipient in matrix tablets

In developing countries modern medicines are often beyond the affordability of the majority of the population. This is due to the reliance on expensive imported raw materials despite the abundance of natural resources which could provide an equivalent or even an improved function. The aim of this study was to investigate the potential of sesamum gum (SG) extracted from the leaves of Sesamum radiatum (readily cultivated in sub-Saharan Africa) as a matrix former. Directly compressed matrix tablets were prepared from the extract and compared with similar matrices of HPMC (K4M) using theophylline as a model water soluble drug. The compaction, swelling, erosion and drug release from the matrices were studied in deionized water, 0.1 N HCl (pH 1.2) and phosphate buffer (pH 6.8) using USP apparatus II. The data from the swelling, erosion and drug release studies were also fitted into the respective mathematical models. Results showed that the matrices underwent a combination of swelling and erosion, with the swelling action being controlled by the rate of hydration in the medium. SG also controlled the release of theophylline similar to the HPMC and therefore may have use as an alternative excipient in regions where Sesamum radiatum can be easily cultivated