Bioadhesive Polymer Buccal Patches for Buprenorphine Controlled Delivery: Solubility Consideration

Abstract

By using a two-roll milling method, a new bioadhesive polymer patch formulation for buprenorphine controlled delivery and consisting of polyisobutylene, polyisoprene, and Carbopol® 934P was prepared. Since solubility of drug in the polymer patches is the first factor which should be considered before to modify the feasibility of delivering drug through the buccal mucosa, the effects of α-cyclodextrin, β-cyclodextrin, sodium taurocholate, and sodium glycodeoxycholate on the solubility of buprenorphine were investigated, and β-cyclodextrin was found the strongest solubility enhancer of them. The drug release profiles were significantly affected by the drug loading and the existence of β-cyclodextrin. Increasing the drug loading and solubility enhancer would increase the drug release from the buccal polymer patches. The pH value change in the microenviroment of polymer patches during the hydration of Carbopol® 934P could even release 20% of drug from the polymer patches which didn't contain any solubility enhancer.