Chapter 16

Drug and Gene Therapy Mediated by Physical Methods

John M. Nickerson and Jeffrey H. Boatright

Abstract  A strategy to deliver drugs to the posterior segment of the eye is via a combination of physical methods to place the drug adjacent to the target cell and to open the cell membrane so that the drug can pass into the cell. Electric fields can be used to transport small and large charged molecules and to open pores in the plasma membrane. Here we review these physical methods and the progress to exploit electric fields in drug delivery.

16.1  Introduction

Effective drug treatment in the posterior segment remains a challenge for ophthalmologists and pharmaceutical scientists. Several physical approaches offer the opportunity to deliver drugs or other agents to the posterior segment and into the interior of a target cell. Some of these processes overcome drug delivery impediments by use of electromagnetic fields to transiently break or disrupt barriers to cell entry, and the techniques include most frequently: iontophoresis, electroporation, electrophoresis, or photo-acoustic energies to accomplish delivery. While none of these technologies is new, improvements to these approaches now offer realistic drug delivery via these physical methods. These physical methods often may be used in conjunction with other approaches such as formulation of drugs in nanoor microparticles for sustained long-term drug release and local delivery via injection at the target site to enhance efficacy.

J.M. Nickerson (*)

Department of Ophthalmology, Emory University, 1365B Clifton Road, Atlanta, GA 30322, USA e-mail: litjn@emory.edu

U.B. Kompella and H.F. Edelhauser (eds.), Drug Product Development for the Back of the Eye, 391 AAPS Advances in the Pharmaceutical Sciences Series 2, DOI 10.1007/978-1-4419-9920-7_16,

© American Association of Pharmaceutical Scientists, 2011