Effect of pectin type and plasticizer on in vitro mucoadhesion of free films.

The objective was to measure and compare the specific and general mucin interaction of plasticized and unplasticized pectin films. The pectin types differed in the type and degree of substitution. Mucoadhesive properties were measured by using a texture analyzer. Pectin with an intermediate degree of methoxylation (36%) displayed substantially higher general and specific mucin interaction than amidated, acetylated, and high methoxylated pectin. This was explained with extensive hydrogen bonding in addition to favorable wetting properties. When comparing all plasticized films to all unplasticized films, a consistent and statistically significant increase in the peak force was observed on adding an effective plasticizer.