Non-ionic hydroxyethylcellulose (HEC) has limited mucoadhesive properties for application in transmucosal drug delivery. In this study, HEC was chemically modified by reaction with glycidyl methacrylate. This allowed introducing the methacryloyl groups to HEC structure to make it capable of forming covalent bonds with the sulfhydryl groups present in the mucin glycoprotein to achieve enhanced mucoadhesive properties. The results showed a successful modification of HEC as confirmed by 1H NMR and FTIR spectroscopies. The quantification of methacryloyl moieties was conducted using HPLC. The toxicity studies using in vivo planaria acute toxicity assay, in vivo planaria fluorescent test, and in vitro MTT assay with Caco-2 cell line confirmed that the chemical modification of HEC does not result in any toxicological effects. Mucoadhesive wafers were developed based on parent and modified HEC as a model dosage form for buccal delivery. The mucoadhesive properties of modified HEC assessed using a tensile test were found to be significantly better compared to unmodified HEC.
Keywords: hydroxyethylcellulose; methacryloyl; mucoadhesion; transmucosal delivery; wafers.