Enhanced Bioavailability of Nimodipine from Bioadhesive Buccal Bilayered Patches in Human Volunteers

Aims: The objective of the present study was to develop a bioadhesive bilayered buccal patch of Nimodipine (15 mg) using Eudragit Rs 100 as secondary layer and a primary layer with Hydroxy propyl methyl cellulose and Hydroxy propyl cellulose JF.
Methodology: Bilayered buccal patches were prepared by solvent casting technique. The absence of physiochemical interactions between NMDP and the polymer were investigated by differential scanning calorimetry (DSC). Bilayered buccal patches of NMDP were evaluated for in vitro drug permeation through porcine buccal membrane, in vitro drug release, moisture absorption, surface pH, mechanical properties and in vitro bioadhesion.
Results: The results indicated that suitable bioadhesive bilayered buccal patches with desired permeability could be prepared. The bioavailability study was performed in healthy humans in a crossover experimental design. Bioavailability studies revealed that nimodipine possessed good buccal absorption. The relative bioavailability of the optimized buccal patch was found to be 205% in comparison to 30 mg marketed oral tablet. The formulation CC3 showed 68.84 ± 1.4% release and 46.85 ± 5.1% of drug permeated through porcine buccal membrane in 4 hr. A good correlation was seen between percentage in vitro release the extent of bioavailability for nimodine buccal patch.
Conclusion: An improvement of bioavailability was obtained by buccal route to the extent of 2.05 times higher than that of oral route for NMDP. Hence, the development of a bioadhesive bilayered buccal patch for NMDP might be a promising one, as the necessary dose of drug could be decreased, resulting less side effects. Good ex vivo - in vivo correlation was obtained for NMDP.