Proniosomes as a novel drug carrier system for buccal delivery of benzocaine

Benzocaine proniosomal gel formulations were prepared using Span 60, Span 80 or Span 85 and their mixtures. Drug entrapment efficiency increased with the increase of the ratio of Span 80 or Span 85 in the surfactant mixture from 8.19 % up to 26.21 %. The addition of Span 80 or Span 85 to Span 60 obviously decreased the vesicle sizes from 825 to 190 nm. The in vitro release pattern of Benzocaine showed an initial fast release followed by a slower release rate. Formulations containing Span 80 and Span 85 showed better rate and extent of Benzocaine permeation when examined using chicken pouch as a model mucosal membrane. Physical stability studies showed a drug retention of > 90 % after storage for 30 days at 4-8 °C. This study shows the potential of using proniosomal benzocaine as an effective, long acting vesicular formulation for improving local anesthesia in the buccal cavity.