Analysis of interactions between polymeric gel and esophageal mucosae by a multivariate experimental approach

Gels with mucoadhesive properties have been proposed to deliver drugs by several routes of administration. The aim of this work was to study the in vitro mucoadhesion of a polymeric gel on pig esophageal mucosa by the tensile strength analysis using a texturometer and to evaluate the influence of instrumental variables on mucoadhesive properties. The influence of contact force, contact time, probe withdrawal speed and volume of hydration liquid on measured maximum detachment force and detachment work was studied using a multivariate approach. The results showed that the detachment force was clearly influenced by the contact force, contact time, probe withdrawal speed and their interactions. The values of maximum detachment force and work varied from 0.090 to 1.710 N and 0.089–0.788 N.mm, respectively. The values of standard deviations for both force and work were proposed to indicate the best experimental conditions and ranged from 0.004 to 1.129 and 0.001 to 0.305, respectively. The optimal conditions for detachment force and work measurement were determined by the desirability function methodology, resulting in experimental values of 0.5008 ± 0.0840 N and 0.2967 ± 0.0484 N.mm, respectively. The approach of using standard deviations to optimize experimental conditions proved to be effective for reproducible assays.