Comparison of the transdermal ballistic delivery of micro-particles into human and porcine skin

This paper describes a comparative investigation into the impact penetration characteristics of DNA-coated gold micro-particles into human and porcine skin. This work is aimed at establishing the link between the particle parameters required in delivering particles to the epidermis of pigs and humans. The particles are delivered to the skin using the PowderJect concept: a method that accelerates vaccines and drugs in microparticle form to velocities sufficient to penetrate the skin and achieve a therapeutic effect. Devices are configured to deliver particles to predetermined velocities to both the in-vivo inguinal region of the pig and the ex-vivo skin from the human back and arm. Location of the gold particles within the tissue sites was assayed in histological sections taken from the tissue sites. The penetration results in pig and human tissue are analyzed and compared with calculations performed with a semi-empirical unified penetration model.