P. Maffei, S. Borgia, A. Sforzini
2004
Citations
1
Influential Citations
8
Citations
Quality indicators
Journal
Journal of Drug Delivery Science and Technology
Abstract
Benzocaine is used in the stomatological field as regional anaesthetic for dental procedures and in the treatment of oral mucositis pain resulting from chemotherapy. In this study, double layered tablets containing benzocaine were specifically developed for local buccal administration. The tablets are made up of a mucoadhesive layer containing the drug and a protective layer covering the lower layer. The objective of the study was to create a tablet able to adhere to the buccal mucosa while giving local controlled release of the drug. A number of tablets were developed having different release rates and different protective layer thicknesses. In order to study the drug release from the mucoadhesive layer of the tablets, four different types of in vitro testing activities were performed. Initially, testing was carried out using a specific new apparatus developed to replicate the physiological conditions in the oral cavity. Testing was also carried out using the official release method by means of the USP 23/NF paddle apparatus. The third cycle of evaluation used a modified version of the paddle apparatus. While the last type of test was carried out in modified Franz diffusion cells allowing a contemporaneous study of the drug release rate from the tablets and of the drug permeation through the buccal mucosa. In vitro tests results were compared to in vivo release test results. In vitro and in vivo experiments pointed out that, of the tablets studied, the bi-layered tablets with the thickest protective layers were the most efficient in guaranteeing a controlled and prolonged release of the drug towards the mucosa. Of the in vitro release tests, the Franz diffusion cell test gave the release profile that most closely resembled the in vivo data.