Formulation of Diphenhydramine mucoadhesive Paste and evaluation of it's Physicochemical Characteristics

Aphthous stomatitis is one of the common mouth problems. Several medical procedures have been suggested for its treatment. Diphenhydramine has been commonly used to control aphthous pain because of its local anaesthetic effect. One of the important factors that determine its effectiveness in the treatment of aphthous ulcer is persistent at the location. Some of mucoadhesive drug formulations such as Adcortyl (containing corticosteroids)have several inherent side effects like candidiasis. The purpose of this research was to prepare a mucoadhesive formulation of diphenhydramine in a suitable base which can be used in the treatment of aphthous stomatitis. In the first stage, low-density propylene glycol (LDPE) and liquid paraffin were used for preparing the plastibase by shock cooling method. This base was quality-tested and the suitable method to prepare the mucoadhesive base was determined. In the second stage of work, ten formulations containing different concentrations of gelatine, pectin, Na-CMC were prepared. The adhesive strengths, the occlusivity and the spreadability of the pastes were studied. The selected preparations were tested for drug release studies by Franz diffusion cell. The results showed that the selected formulation has the adhesive strengths equal to 109 mNcm-2 similar to the commercial product with a release drug flux rate of 6.7 g/cm2min. These results showed that diphenhydramine can be formulated in a mucoadhesive base with proper mucoadherence, exclusivity, occlusivity spreadability with suitable release profile that makes it useful for use in aphthous stomatitis