Starch bioadhesive microspheres

Fundueanu, G, Constantin, M., Dalpiaz, A., Bortolotti, F., Cortesi, R., Ascenzi, P., and Menegatti, E. (2004), Freparation and characterization of starch/cyclodextrin bioadhesive microspheres as platform for nasal administration of Gabexate Mesylate (Foy(r)) in allergic rhinitis treatment, Biomaterials, 25,159-170. 

Nakamura et al. ° studied the adhesion of water-soluble and neutral polymers, hydroxypropyl cellulose (HPC), xanthan gum (XG), tamarind gum (TG), and polyvinyl alcohol (PVA) to nasal mucosa in vitro and in vivo. The polymers, mixed with a dye, were applied as powders to the nasal cavity of rabbits, and the remaining dye residue was determined at 2, 4, and 6 h after nasal instillation with a thin fiberscope. The polymer XG showed the longest residence time of the dye in the cavity, followed by TG, HPC, and PVA in decreasing order. For the mixture XG and XG-PVA (2 8), some residue of dye could still be observed 6h after administration. The order of adhesion of these polymers to agar plates in vitro agreed with that of their mucoadhesion in vivo. Ilium et al. introduced bioadhesive microspheres for nasal delivery of poorly absorbable drugs. Radiolabelled microspheres made from diethylaminoethyl (DEAE)-dextran, starch microspheres, and albumin microspheres were administered to human volunteers and appeared to be cleared significantly slower than solutions or... 

Fabrication Common preparation techniqnes discussed in earlier sections are nsed in formnlating bioadhesive microspheres. An important criterion is the use of bioadhesive polymers like chitosan, hyaluronic acid, starch, lysophosphatidylcholine along with degradable starch microspheres. 

Ilium, L., et al. 2001. Bioadhesive starch microspheres and absorption enhancing agents act synergistically to enhance the nasal absorption of polypeptides. Int J Pharm 222 109. 

To increase the residence time in the nasal mucosa, a bioadhesive formulation may be one of the most reasonable approaches. In fact, microspheres containing bioadhesive polymers such as starch, albumin, and Sephadex with a particle size of 40-60 pm have been found to be cleared from the nasal cavity much more slowly than solutions. Starch microspheres improved the nasal absorption of insulin, with synergistic effects of some absorption enhancers in sheep. In another paper, dry powder containing starch and Carbopol 974P showed significantly higher bioavailability after nasal administration than the formulation without Carbopol. ° Chitosan, already mentioned above, also has a bioadhesive property and is found to be useful as a potent absorption enhancer for nasal peptide delivery. Other bioadhesive polymer systems,... 

Ilium (1991) demonstrated protein absorption from bioadhesive starch microspheres containing insulin or HGH delivered intranasally in experiments conducted in sheep. 

Starch 1. Slow release drug delivery system based on amylose-rich starch has been marketed under the trade name Contramid . 2. Starch microspheres have been investigated as a bioadhesive drug delivery system for the nasal delivery of proteins. Khanlari and Dube (2013), Nair and Laurencin (2006), and Marques et al. (2002)... 

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