Nasal vaccination delivery systems

TABLE 5 Nasal Vaccination Delivery Systems Studied ... 

A number of adjuvants are awaiting approval for human use. The main impediment to the successful development of vaccine adjuvants is that their mechanism of action is not clearly understood. Table 5 offers a fist of available nasal drug delivery systems and the various adjuvants that have been used in the development of nasal vaccines. 

Its biodegradability and low toxicity in humans have aided the recent increased interest in chitosan as an immunopotentiating agent. In vivo studies have demonstrated that chitosan powder and solution formulations are able to enhance the systemic and mucosal immune responses after nasal vaccine delivery [19, 22, 76],... 

Several studies in animal models have been carried out to prepare chitosan microparticles-based vaccines against influenza, pertussis, and diphtheria. The nasal chitosan vaccine delivery system has been tested for vaccination against influenza in humans [56]. The results showed that it was both effective and protective according to the Committee for Proprietary Medical Products (CPMP) requirements. 

Since the uptake of particles in nasal epithelial tissue is known to be mostly mediated by M cells, nasal administration has been investigated as a noninva-sive delivery of vaccines [37], However, since the uptake of naked DNA by endocytocis is limited, use of either nanoparticles as mucosal delivery systems [37] or hypotonic shock [38] is reported for the efficient transfection of gene and vaccine into the nasal epithelium. It was also reported that polypeptides and polypeptide-coated nanospheres (diameter about 500 nm) are transported through endocytic process in rat M cells [39],... 

The most potent mucosal adjuvants have been shown to be the toxins derived from Vibrio cholerae or Escherichia coli, which should not be surprising since these organisms invade the body through the GI tract. Obviously too toxic for human use because they are the source of cholera or diarrhoea, heat labile enterotoxins have been tested in mice and shown to be potent adjuvants for orally or nasally administered influenza vaccine. The potency of heat-labile enterotoxin mutants may also be enhanced by formulation into bioadhesive particulate delivery systems, and this is an area under current exploration. 

Ilium L, et al. (2001). Chitosan as a novel nasal delivery system for vaccines. Adv. Drug Deliv. Rev. 51 81-96. 

Heffeman MJ, Zaharoff DA, Fallon JK, Schlom J, Greiner JW (2011) hi vivo efficacy of a chitosan/lL-12 adjuvant system for protein-based vaccines. Biomaterials 32(3) 926-932 Ilium L, Jabbal-Gill I, Hinchcliffe M, Fisher AN, Davis SS (2001) Chitosan as anovel nasal delivery system for vaccines. Adv Drug Deliv Rev 51(l-3) 81-96... 

The use of ttaditional disperse systems, e.g., macroemulsions, in the pharmaceutical industry has been limited due to manufacturing complexity and stability problems [117]. The characteristic properties of nano-emulsions (kinetic stability, small and controlled droplet size, etc.) make them interesting systems for pharmaceutical applications. Indeed, nano-emulsions are used as drug delivery systems for administration through various systemic routes. There are numerous publications on nano-emulsions as drug delivery systems for parenteral [17,18,28,29,118-124], oral [25,125-129], and topical administration, which includes the administration of formulations to the external surfaces of the body skin [32,130,131] and to the body cavities nasal [30,132] as weU as ocular administration [31,133-136]. Moreover, many patents concerning pharmaceutical applications of nano-emulsions have been registered [17,18,25,137-145]. An application of nano-emulsions in this field has been in the development of vaccines [33,146-147]. 

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