Dexamethasone sodium phosphate-loaded Chitosan based delivery systems for buccal application

Chitosan(CH)wasusedasabiocompatibleandbioadhesivepolymermaterialtopreparesoliddispersionsaswellashydrogels loaded with dexamethasone sodium phosphate (DSP), a steroidal anti-inflammatory agent clinically used for treatment of different mouth diseases. Binarysoliddispersions atvariousdrug-to-polymerweightratioswere preparedbyfreeze-drying; theirdirect compression gave tablets which were characterized for the swelling behaviour and drug release in vitro. Similarly, DSP-loaded hydrogels composed of CH and glycerine were prepared and characterized. CH and DSP showed a good physical compatibility. A slow and prolonged release of the drug was observed in vitro from both kinds of systems. The swelling properties of the polymer seemed to be the main parameter affecting the drug release profile from both tablets and hydrogels at the pH value of mouth. In vivo buccal application of both the systems allowed to obtain a prolonged release of DSP, as compared with a glycerine solutionofthedrug.Fromthe in vitro swelling studies and in vivotest, the2:1CH-DSPsoliddispersion in particular canbe designated for further investigation.