Approaches For Improvement On Bioadhesive Properties Of Oral Film

Objective:The main objective of this study is to elucidate the influence o f material composites and surface morphology on in vitro muco-adhesive prope rties of oral film,and to clarify the effect of drug loading on the film propert ies.This study will not only promote the deeper research of muco-adhesion process of oral film,and also lay a foundation for development of muco-adhesive dosage forms and new products.Methods:Templates with different surface morphology were prepared by P olydimethylsiloxane(PDMS)copying method,and oral films with different mat erials,surface morphology or drugs were further prepared using solvent casting method.With the in vitro mucosal adhesion,shear and adhesion time as inde x,the obtained films were tested and compared.Dissolution and mucosal perm eability profiles were prepared by disk method and Franz method,respectively.investigate The therapeutic effectiveness of insulin-loaded film was evaluated by blood sugar monitoring in normal rats.Results:(1)Different materials showed significant difference on mucoadhes ion properties.The material composites improved mucous membrane adhesion p erformance.The adhesion force of sodium alginate and chitosan compound film was 0.602 N/cm~2,which were 3.7 times and 2.6 times higher than that of pu re sodium alginate and chitosan.All containing chitosan films were not strippe d within 40h.(2)PDMS method can precisely and repeatedly produce oral fim s with the same surface morphology as master template.Surface morphology o f oral films can also significantly affect the mucoadhesion properties.The adhe sion and shear forces of#400 were 1.6 times and 1.6 times of the smooth su rface film.For different film with three-dimensional structure,both palisade sur face and needle surface of film possessed remarkable improvement on the muc oadhesion performance.The adhesion force and shear force of needle surface fi lm prepared by sodium alginate and chitosan composites was 2.1 times and 1.9times of the smooth surface film.Films with different leaf morphologyexhibite d different adhesion in certain degree.The adhesion force and shearing force o f sunflower leaf film prepared with sodium alginate and chitosan composites w ere 1.4 times and 1.8 times of smooth surface film.(4)The films loaded with metformin hydrochloride,insulin or tinidazole nanocrystalline showed good film-forming property,and changed the surface morphology of films.However,no significant change on the in vitro adhesion properties of film was observed.Th e pharmacodynamic results showed that insulin-loaded films showed a moderate effect of lowering blood glucose and could maintain a steady level in longer period compared to the injection group.Conclusion:The bioadhesive propertieoral films can be improved by either combination use of different film material or morphological modification of fil m surface,and the film properties was changed on a certain degree after drug loading.This study provided a theoretical basis for bio-adhesion improvement of oral film.