Gastrointestinal delivery systems chitosan

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

Chitosan Beads, Microcapsules and Microspheres for Gastrointestinal Delivery Systems... 

Hejazi, R Amiji, M. Chitosan-based gastrointestinal delivery systems. Jovmal of Controlled Release, 89, 2003,151-165. 

In a PEC used to deliver a protein, the latter is often used as one of the polyelectrolyte components of the complex. Examples of PECs in which one of the two polyelectrolyte components is an active substance itself, are complexes of chitosan and insulin. The PEC composed of trimethyl chitosan (TMC) and pegylated TMC (PEG-g-TMC) can be obtained simply by mixing the solutions of TMC and insulin at various mass and charge ratios. These PECs were stable in simulated intestinal fluid at pH 6.8. However, they disintegrated in simulated gastrointestinal fluid at pH 1.2. The PECs also protected insulin from temperature-induced denaturation up to 50 °C and from degradation by trypsin. Based on these results, the authors suggested that polyelectrolyte complexation can be a useful technique for fabrication of insulin delivery systems for oral administration. 

Transdermal delivery systems are used to deliver the drug across the skin, into the systemic circulation, to avoid its first pass metabolism and reduce gastrointestinal adverse events. The bioadhesive property and paracellular transport of chitosan has also been... 

Due to the limitations with the gastrointestinal tract, there are few studies available on chitosan-based delivery systems for oral vaccine delivery (Table 1). Van der Lubben et al. [66] were among the first to demonstrate that chitosan microparticles with a particle size smaller than 10 pm, incorporated with the model protein OVA as well as diphtheria toxoid (DT), were taken up by the Peyer s patch after intragastric administration to mice. A dose-dependent immune reaction was observed for mice vaccinated with different doses of DT associated to chitosan microparticles [67]. It was also observed that the immune response started only 1 week after the boosting, indicating the formation of memory cells after priming. 

Oral drug delivery systems provide a safe route for the drugs to be directly released into the gastrointestinal tract. Nano chitosan blended alginate matrix (CBAM) by grafting with poly methacrylic acid (PMAA) recently being developed for the oral drug delivery. Such a system showed... 

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