Ex-vivo and in-vivo Evaluation of Formulated Novel Felodipine Core in Cup Buccal Tablets

Abstract

Novel buccal mucoadhesive tablets of felodipine as core in cup systems preparation and evaluation in-vitro of adhesive cups, core and novel tablets is studied and published in the earlier research paper. In this investigation the formulated novel buccal tablets which are optimized through in-vitro studies are selected and performed the ex-vivo and in-vivo studies on rabbits. Drug permeation study of felodipine buccal tablets was carried out using porcine buccal mucosa, which was procured from local slaughter house and placed in Krebs buffer pH 6.8. In-vivo experiments were conducted after approval of the protocol from Institutional Animals Ethics Committee. As per the protocol, optimized formulations were tested in Albino rabbits for pharmacokinetic studies simultaneously for both formulations. Studies were conducted in rabbits in the weight range of 1.5 to 2.5 kg. From the permeation data different permeation parameters like flux (Jss), permeation coefficient (kp), diffusion coefficient (D), amount drug permeated at 6 hr and release rate constant (k) were calculated. The flux obtained was 5478.04 to 8478.78 mcg/cm2/h with permeability coefficient of 0.038 to 0.058 cm/h. The peak plasma concentration (Cmax) felodipine in the pure drug and its complex were 233.75±5.40 and 517.25±23.92 ng/mL, while AUC0-6hr and AUC0-∞ were found to be 1867.5±42.07, 2293.04±82.13 ng.hr/mL, 3116.99±116.46 and 36970.91±4044.98 ng.hr/mL respectively. These values indicated maximum plasma concentration and area under the curve were achieved by felodipine complex formulation. Cmax value was 2.3 times and AUC0-12hr was 1.56 times higher for complex than felodipine. The relative percent bioavailability (Frel) of felodipine complex observed was 130.58% indicated enhanced oral bioavailability of felodipine complex.