Abstract

The aim of present study is to investigate the effect of flow aids on the observed in vitro mucoadhesion of two representative polymers; polyoxyethylene and Carbopol® 971P. More recently it has been shown that the addition of small amounts of certain excipients to a mucoadhesive formulation can lead to a substantial decrease in observed mucoadhesion in an in vitro test system, which suggests that formulation of these systems could be crucial in developing successful dosage forms. A series of experiments has been carried out which indicates that the presence of flow aids at high concentrations present in tablets can affect the observed ex-vivo mucoadhesive bond. Magnesium stearate (5%) exerts its negative effect on the mucoadhesion of Carbopol® 971P and polyoxyethylene combination by hindering the hydration of the polymer. Adhesion time of formulation containing 5% magnesium stearate was found 4.7±0.34 h and percent hydration of same formulation was 70.12%.Talc and colloidal silicon dioxide (Aerosil), which do not possess the same hydrophobic properties or have available divalent cations were found to be viable alternatives to magnesium stearate.