Chitosan delivery systems

Koping-Hoggard et al. [68] established the relationships between the structure and the properties of chitosan-pDNA polyplexes in vitro and in vivo. They compared polyplexes of ultrapure chitosan (UPC) of preferred molecular structure with those of polyethylenimine (PEI) polyplexes in vitro and after intratracheal administration to mice in vivo. UPC carriers were less cytotoxic than polyethylenimine (PEI) polyplexes and provided a better efficiency compared with that of commonly used cationic lipids. Low-molecular weight chitosan delivery systems were more efficient for cell transfection and less cytotoxic compared with PEL [65]. 

Baudner, B.C., Morandi, M., Giuliani, M.M. et al. 2004. Modulation of immune response to group C meningococcal conjugate vaccine given intranasally to mice together with the LTK63 mucosal adjuvant and the trimethyl chitosan delivery system. J. Infect. Dis. 189 828-832. 

Chitosan has demonstrated haemeostatic activity, which is suggested to be originated by the interaction between the cell membrane of erythrocytes and chitosan. The occurrence of clot formation is in the absence of coagulation factors or platelets [21]. Positively charged chitosan delivery systems tend to attract the circulating plasma proteins, which... 

Hamman et al. [281,282] tested five trimethyl chitosans with different degrees of quaternization as nasal delivery systems the degree of quaternization had a major role in the absorption enhancement of this polymer across the nasal epithelia in a neutral environment. 

Associations can be of physical nature too. Chitosan blends with hydrophilic polymers including polyvinylalcohol, polyethyleneoxide and poly-vinylpyrrohdone, were investigated as candidates for oral gingival delivery systems. Chitosan blends were superior to chitosan alone in terms of comfort, ease of processing, film quality, and flexibihty [325]. 

Wu J, Wei W, Wang LY, Su ZG, Ma GH (2007) A thermosensitive hydrogel based on quatemized chitosan and polyethylene glycol) for nasal drug delivery system. Biomaterials 28 2220-2232. 

A. H. Krauland, V. M. Leitner, V. Grabovac, and A. Bernkop-Schnurch. In vivo evaluation of a nasal insulin delivery system based on thiolated chitosan. J Pharm Sci 95 2463-2472 (2006). 

Aiedeh, K., and Taha, M.O., Synthesis of chitosan succinate and chitosan phthalate and their evaluation as suggested matrices in orall administered, colon-specific drug delivery systems, Arch. Pharm (Weinheim), 332 103-107 (1999). 

Solid dispersions have been explored as drug delivery systems for over 30 years, initially starting with various forms of polyethylene glycols, citric and succinic acids, and sugars. However, more recent success has been achieved using hydroxypropy-lcellulose (HPC), ethylcellulose (EC), and the commercial forms of methylacrylic acids and their copolymers sold under the name Eudragits. In addition, chitosans have been evaluated for this purpose. 

Leone, M.M., Nankervis, R., Smith, A., and Ilium, L. (2004). Use of the ninhydrin assay to measure the release of chitosan from oral delivery systems. Int. J. Pharmaceut., 271, 241-243. 

Richardson, S.C.W., Kolbe, H.V.J., Duncan, R. (1999). Potential of low molecular mass chitosan as a DNA delivery system biocompatibility, body distribution and ability to complex and protect DNA. Int J. Pharm., 178, 231-243. 

Chitosan has been the focus of reasearch as a pharmaceutical excipient due to its specific chemically and biologically favorable features [6-8]. As chitosan is soluble in acidic aqueous solutions, it can be processed under acidic conditions. By contrast, as the product made by chitosan is insoluble at neutral or basic pH, it behaves as a delivery system under such conditions. These chemical properties allow chitosan to control drug delivery. Further,... 

Hejazi, R., and M. Amiji. 2003. Chitosan-based gastrointestinal delivery systems. J Control Release 89 151. 

Pan, Y., et al. 2002. Bioadhesive polysaccharide in protein delivery system chitosan nanoparticles improve the intestinal absorption of insulin in vivo. Int J Pharm 249 139. 

Bernkop-Schnurch, A., D. Guggi, and Y. Pinter. 2004. Thiolated chitosans development and in vitro evaluation of a mucoadhesive, permeation enhancing oral drug delivery system. J Control Release 94 177. 

Foger, F., T. Schmitz, and A. Bernkop-Schniirch. 2006. In vivo evaluation of an oral delivery system for P-gp substrates based on thiolated chitosan. Biomaterials 27 4250. 

Lim, S.T., et al. 2002. In vivo evaluation of novel hyaluronan/chitosan microparticulate delivery systems for the nasal delivery of gentamicin in rabbits. Int J Pharm 231 73. 

Ilium, L., N.F. Farraj, and S.S. Davis. 1994. Chitosan as a novel delivery system for peptide drugs. Pharm Res 11 1186. 

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