Evaluation of bioadhesive properties of excipients containing lipophilic adjuvants

The aim of the study was to prepare and evaluate excipients with bioadhesive, properties obtained by means of lipophilic adjuvants which may be used as the active substance carriers providing prolonged contact with the oral mucosa. Light liquid paraffin, polyethylene, polydocanol and polymers with mucoadhesive properties: methylcellulose, pectin and gelatin have all been used in the study. The addition of paraffin to the excipients has been found to prolong the time of their washing down in water and in artificial saliva as well as to affect the rheological properties of the obtained formulations in comparison to standard preparations obtained on the basis of hydrophilic and lipophilic excipients. The analysis of rheological properties revealed that the flow curves of prepared formulations could be described on the basis of nonlinear models of Herschel-Bulkley and Ostwald-de Waele type.