In vitro and in vivo evaluation of a novel mucoadhesive buccal oxytocin tablet prepared with Dillenia indica fruit mucilage.

Novel mucoadhesive buccal tablets (NMBT) of oxytocin were prepared as core in cup fashion to release the drug unidirectionally towards the buccal mucosa. Adhesive cups were prepared with a mucilage isolated from edible Dillenia indica fruits (DIM). Shear, tensile and peel strengths of prepared adhesive cups were estimated on freshly excised bovine buccal mucosa. Core tablets were formulated with oxytocin using permeation enhancers viz. sodium taurocholate and sodium thioglycollate. In vitro permeability studies of NMBT were conducted in a Franz diffusion cell containing 50 mL of phosphate buffer pH 6.6 at 37 +/- 0.2 degrees C through excised bovine buccal mucosa. In vivo studies on anaesthetized New Zealand albino male rabbits were conducted and drug levels in plasma were estimated at 220 nm by reverse phase HPLC using BDS Hypersil C8 column using acetonitrile and 0.05 M potassium dihydrogen orthophosphate buffer pH 6.6 (20:80 v/v) as mobile phase, at a flow rate of 1.25 mL/ min. Optimized formulation showed C(max), T(max), t1/2 and AUC(total), 688 pg/mL, 2 h, 0.079 h, and 1999.72 h x pg/mL respectively. The NMBT containing 0.75% w/w sodium taurocholate showed 27% bioavailability without damaging the buccal mucosasuggesting its suitability as an alternative to noninvasive administration of oxytocin.