Sa. Mortazavi et Jd. Smart, FACTORS INFLUENCING GEL-STRENGTHENING AT THE MUCOADHESIVE-MUCUS INTERFACE, Journal of Pharmacy and Pharmacology, 46(2), 1994, pp. 86-90
Mechanical spectroscopy was used to examine some of the factors that m
ay affect mucus gel strengthening: the effect of adding various concen
trations of sodium chloride; mucoadhesive polymer molecular weight and
its concentration; and the introduction of anionic, cationic and neut
ral polymers. A reduction in the storage modulus of the mucus/mucoadhe
sive mixture was observed with the introduction of sodium chloride. A
poly(acrylic acid) with a molecular weight of 750 kDa gave the optimum
mucus gel strengthening effect relative to other molecular weights. A
n anionic polymer was found to strengthen the mucus gel much more than
a neutral or cationic polymer. It was proposed that the gel strengthe
ning effect could be due to the formation of hydrogen bonded intermole
cular complexes between the mucoadhesive and the mucus molecules. Furt
hermore, the complex formed is influenced by the ionic strength of the
environment, and the molecular weight, nature and concentration of th
e mucoadhesive. In all cases the changes in the theological properties
of the mixes could be correlated directly to the strength of mucoadhe
sion reported in previous studies.