Mucoadhesive potential

Fiebrig I (1995) Solution Studies on the Mucoadhesive Potential of Various Polymers for use in Gastrointestinal Drug Delivery Systems. PhD Thesis, University of Nottingham, Nottingham, UK... 

Effect of Molecular Weight of Chitosan and Its TBA Conjugate on Mucoadhesive Potentials... 

Besides the polymer derivatization, combining the polymers in microsphere preparations can result in improved drug delivery and absorption characteristics. Hyaluronic acid-chitosan microspheres appeared to improve the absorption of incorporated gentamicin compared to the individual polymers, assembling the mucoadhesive potential of both polymers and the penetration-enhancing effect of chitosan [51,52],... 

Kockisch S, Rees GD, Young SA, et al. Polymeric microspheres for drug delivery to the oral cavity an in vitro evaluation of mucoadhesive potential. / Pharm Sci 2003 92(8) 1614-1623. 

TMC NP was more effective than chitosan nanoparticles and polymer solutions in enhancing permeation across jejunum tissue because the pH of the microclimate mucus environment (pH 6-6.5) was disadvantageous to chitosan and TMC NP has high mucoadhesive potential. Both TMC and chitosan failed penetration enhancement across the ileum, probably due to a thicker mucus layer with barrier properties... 

The approach is to first of all obtain mucin to a high degree of purity and to characterise the mucin and potential mucoadhesive. This is done by sedimentation velocity [g (s)j analysis and sedimentation equilibrium (M ) analysis—according to the procedures described above—together with SEC-MALLs [145,146]. 

Borchard, G. LueBen, H.L. deBoer, A. G. Verhoef, J. C. Lehr, C.-M. Junginger, H.E., The potential of mucoadhesive polymers in enhancing intestinal peptide drug absorption. Ill Effects of chitosan-glutamate and carbomer on epithelial tight junctions in vitro, j. Control. Rel. 39, 131-138 (1996). 

Saettone et al. [62] evaluated low viseosity polymers (polygalacturonic acid, hyaluronic acid, carboxymethylamylose, carboxymethylchitin, chondroitin sulfate, heparan sulfate, and mesoglyean) as potential mucoadhesive carriers for cyclopentolate and pilocarpine in a study of their influence on miotic activity in rabbits. Small but significant increases in bioavailability were observed and a correlation was foimd between the bioavailability of the two drugs and the mucoadhesive bond strength of the polymers investigated. 

These stabilizers are added to the formulation in order to stabilize the emulsion formed during particle preparation. These stabilizers, however, can also influence the properties of the particles formed. The type and concentration of the stabilizer selected may affect the particle size. Being present at the boundary layer between the water phase and the organic phase during particle formation, the stabilizer can also be incorporated on the particle surface, modifying particle properties such as particle zeta potential and mucoadhesion (203). Other polymers have also been evaluated as stabilizers in earlier studies such as cellulosic derivatives methylcellu-lose (MC), hydroxyethylcellulose ( ), hydroxypropylcellulose (HPC), and hydroxypropylmethylcellulose (HPMC), as well as gelatin type A and B, carbomer and poloxamer (203). 

Bogotaj, M., et al. 2003. The correlation between zeta potential and mucoadhesion strength on pig vesical mucosa. Biol Pharm Bull 26 743. 

Mucus turnover rate. The turnover rate of the mucus layer is another physiological factor that affects mucoadhesion. Mucus turnover limits the potential duration of adhesion at the desired site of application. Within the GI tract, mucus is lost continuously secondary to enzymatic degradation (pepsin, lysosomal enzymes, and pancreatic enzymes), acid... 

Singla, A. K., Chawla, M., and Singh, A. Potential applications of carbomer in oral mucoadhesive controlled drug delivery system A review. Drug Dev. Ind. Pharm. 26 913-924, 2000. 

Lin J., Haruta A., Kawano H., Ho S.B., Adams G.L., Juhn S.K. and Kim Y. (2000) Induction of mucin gene expression in middle ear of rats by tumor necrosis factor-alpha potential cause for mucoid otitis media. J Infect Dis 182, 882-887 Madsen F., Eberth K. and Smart J.D. (1998) A Rheological examination of the Mucoadhe-sive/Mucus Interaction the Effect of Mucoadhesive Type and Concetration. J. Control Release 50, 167-178... 

Fig. 10.2 Zeta potential of mucoadhesive liposomes in a phosphate buffer solution (pH 7.4) (taken from Takeuchi et al. 1996). Lipid composition DPPC DCP = 8 2...

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