Bioadhesive lozenge for the improved delivery of cetylpyridinium chloride

Conventional lozenges produce a high initial release of drug in the oral cavity, which rapidly declines to subtherapeutic levels, and requires multiple daily administration with associated problems of systemic toxicity and compliance. Various multilayer compacts containing cetylpyridinium chloride were evaluated in vitro using release into simulated saliva (buffer pH 6.6). The drug loading, the wax content of the active layer, and the composition of the bioadhesive layer were important variables affecting product performance. Following preliminary in vivo studies, the release of a three-layered device containing drug in a nonadhesive and flavored waxy exposed layer was studied in six humans using HPLC and was shown not to be affected by location within the mouth. In comparison with a proprietary lozenge formulation, the device produced more uniform and effective levels of drug (approximately 20 micrograms.mL-1), with adequate comfort, taste, and irritancy over a period of 3 h.