Buccal films as the dressing for oral mucosa treatment – in vivo study

Buccal flexible films in the form of solid, thin, mucoadhesive patches can be used as dressings separating the mucosal lesion from the environment of the oral cavity. Their advantages include flexibility, application comfort, patient compliance, and better adhesion of the system to the oral mucosa. Moreover, buccal films are able to protect the surface of wound, thus reducing pain and improving effectivity of treatment of oral diseases.  The aim of the experiment was the formulation, development, preparation, and in vitro and in vivo evaluation of mucoadhesive films intended to cover oral mucosal defects. Seven different formulations of flexible patches based on mucoadhesive polymers (carmellose sodium and acid form, polyethylene oxide) were prepared using solvent casting method or method of impregnation, respectively. After in vitro evaluation followed by in vivo testing with 22 healthy volunteer, the film with the best characteristics was selected, and its composition was futher optimized.

The second study (approved by the ethical commission of University Hospital Ostrava, Approval No. 25/2013) was an in vivo clinical study on 20 volunteers suffering from aphthous stomatitis (RAS minor) randomly divided into two groups. The first (control) group was treated using standard means, namely by application of disinfectant preparative directly on the mucosal lesion. The other group was treated by an oral disinfectant, however the lesion with applied preparation was covered with the mucoadhesive film, composed of mucoadhesive layer prepared from dispersion of 4% carmellose sodium with 0,5% polyoxyl ethylene and 3% of plasticizer - glycerol and 5% solution of ethylcellulose with dibutylsebacate as backing layer, which demonstrated the longest residence time and good performance in other parameters. Upon receiving a set of three stickers per day that they were to apply until the lesion was completely healed. All patients were instructed about the application of the film and  about filling out the associated study form.

The criteria for statistical evaluation were measurement of the size of the lesions using a caliper in relation to the length of treatment in the groups as well as the subjective perception of the treatment results. The information about the course of treatment were recorded in the questionnaires. The measurements were performed upon start of the treatment (Day 1) and on the examinations (Day 3 and Day 5). During these examinations, photographic documentation was taken as well. 

The statistical analysis proved a significant reduction in the treatment time and in reducing the feeling of pain in the volunteer experimental group.

Acknowledgement

This work was supported by Ministry of Health of Czech Republic, research project NT11396 and IGA VFU Brno, Czech Republic, research project No. 78/2012/FaF.