Topical liposomal system for localized and controlled drug delivery

A liposomal reservoir system bearing the local anesthetic, benzocaine, was developed for controlled and localized delivery via topical route. The liposomal suspension was incorporated into an ointment and gel base. The developed systems were studied for various physical and kinetic attributes in vitro. The systems delivered the drug at a controlled rate over 24 h, whereas plain drug ointment showed a rapidly decreased release rate over 24 h, with more than 92% released. The drug delivery across human cadaver skin following liposomal ointment application was noted to be considerably slow. The in vivo study revealed a longer duration of action in the case of liposomal formulations. An effort was made to study the effect of ultrasound as a reversible means to effect pulsatile delivery of the drug from the liposomal depot. The work proved the potential of liposomes as a slow release vehicle which follows apparent zero order kinetics and its use in modulating drug input via skin.