LAUSR

Lysozyme is particularly attractive for the local treatment of oral pathologies related to microbiological infections. However, the requirement of a prolonged release is difficult to achieve due to saliva swallowing and to the protein denaturation which can occur during production and storage of a dosage form. This work demonstrates the feasibility to prepare lysozyme mucoadhesive tablets by freeze-drying. Tablets were prepared by using alginate (ALG) physically "cross-linked" with calcium ion and different grades of HPMC (i.e. E5, E50 or K100). The tablets were characterized in terms of swelling/erosion behavior, in vitro mucoadhesive properties, lysozyme activity (M. lysodeikticus), drug release and ability to inactivate S. aureus. The formulations prepared with HPMC K100 were discarded due to the fast erosion. All other formulations allowed a sustained release over at least six hours. Independently of composition, lysozyme activity (78311±1873 Unit/mg) significantly decreased in the case of tablets containing 5 and 10% w/w of protein (55000 Units/mg and 33000 Units/mg, respectively). Conversely, no modifications occurred in the case of tablets containing 1% w/w lysozyme. The formulation prepared by ALG/ HPMC E5 7/3 ratio was efficacious against S. aureus. After 3 months of storage at 5±3 °C, no significant decrease in lysozyme activity was observed.