Development and Evaluation of A Buccal Drug Delivery System for the Anti-Anginal Drug-Nicorandil

Drug delivery within the oral cavity may be summarized under buccal, sublingual and local delivery. Among the three routes of drug delivery within the oral cavity, sublingual and buccal are found to be the most effective. Here we have selected buccal drug delivery system because unlike sublingual, buccal is suitable for oral transmucosal delivery system. Buccal is a more preferred route, for the systemic transmucosal drug delivery. The reason that the buccal mucosa has an expanse of smooth muscle and relatively immobile mucosa which makes it a more desirable region for drugs used in oral mucosal drug delivery. Thus, the buccal mucosa is more filled for delivery of less permeable molecules and perhaps peptide drugs. In this present study, nine different buccal tablets containing nicorandil, using various bioadhesive polymers such as CP, PVP, PVA and EC (backing layer), by two different methods. All the nine formulations were used for the determination of physicochemical evaluations, in vitro drug release and in vitro dissolution kinetics. From this work, we conclude that F3 (Content: Nicorandil 3mg, CP 100mg, PVP 80mg and PVA 50mg) and B2 (Content: Nicorandil 5mg, CP 120mg, PVP 80mg) were found to be ideal buccal tablets, with the highest percentage release of 80.83± 0.93% and 87.0± 1.03%, respectively and we also found that the ideal bioadhesive carriers are PVP and PVA, because of high wettability of the mucous membrane of the buccal area. Further studies can be done to improve the buccal delivery system by in vivo permeation studies. They can be employed to examine drug transport across buccal tissues from animal models. Buccal cell cultures have also been suggested as useful in vitro models for buccal drug permeation and metabolism. In vivo methods were first developed by Beckett and Triggs with buccal absorption test, with which the kinetics of drug absorption was measured. The drawbacks of this method include salivary dilution of the drug, accidental swallowing a portion of sample solution, and the inability to localize the drug solution within a specific site. Pharmacokinetic parameters such as bioavailability can then be calculated from the plasma concentration vs time profile. The buccal mucosa offers several advantages for effective drug delivery. The mucosa is well supplied with both vascular and lymphatic drainage, first pass metabolism and in the liver and presystemic elimination in the gastrointestinal tract are avoided. The area is well suited for a retentive device and appears to be acceptable to the patient. With the right dosage form design and formulation, the permeability and the local environment of the mucosa can be controlled and manipulated in order to accommodate drug permeation. Buccal drug delivery is a promising area with continued research, with the aim of systemic delivery of orally inefficient drugs as well as an attractive alternative for non–invasive delivery of potent peptide and protein drug molecules. Bioadhesive studies, animal model and in vivo drug release could be carried out to evaluate the performance of prepared buccal tablets of Nicorandil.