Microparticulate delivery systems

Hillery, A.M., Microparticulate Delivery Systems Potential Drug/Vaccine Carriers via Mucosal Routes, Pharmaceutical Science and Technology Today. 1, 69, 1998. 

Cilurzo, F., et al. 2005. Fast-dissolving mucoadhesive microparticulate delivery system containing piroxicam. Eur J Pharm Sci 24 355. 

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. 

The presence of specific targeting ligands monoclonal antibodies with specificity for M cells, or lectins which bind to specific carbohydrate residues found on M-cells, can increase the uptake of microparticulate delivery systems. 

Leitner, V. M., Guggi, D., Krauland A. H., and Bernkop-Schnurch, A. (2004), Nasal delivery of human growth hormone In vitro and in vivo evaluation of a thiomer/gluta-thione microparticulate delivery system, / Controlled. Release, 100,87-95. 

Biodistribution of liposomes is a very important parameter from the clinical point of view. Liposomes can alter both the tissue distribution and the rate of clearance of the drug by making the drug take on the pharmacokinetic characteristics of the carrier (10, 11). The pharmacokinetic variables of the liposomes depend on the physiochemical characteristics of the liposomes, such as size, surface charge, membrane lipid packing, steric stabilization, dose, and route of administration. As with other microparticulate delivery systems, conventional liposomes are vulnerable to elimination from systemic circulation by the cells of the reticuloendothelial system (RES) (12). The primary sites of accumulation of conventional liposomes are the tumor, liver, and spleen compared with non-liposomal formulations (13). Many studies have shown that within the first 15-30 min after intravenous administration of liposomes between 50 and 80% of the dose is adsorbed by the cells of the RES, primarily by the Kupffer cells of the liver (14-16). 

On the other hand, mixtures of pectin with other materials such as high amylase starch [12,43], chitosan [11,29] and HPMC have been extensively investigated for use in colon-specific drug release formulations [29]. Pectin has also been used in microparticulate delivery systems for ophthalmic preparations and matrix-type transdermal patches [3]. It has also been studied as a taste masker [4]. 

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