title: Ballistic impact of single particles into gelatin: experiments and modeling with application to transdermal pharmaceutical delivery.
abstract: The impact and penetration of high speed particles with the human skin is of interest for targeted drug delivery by transdermal powder injection. However, it is often difficult to perform penetration experiments on dermal tissue using micron scale particles. To address this, a finite element model of the impact and penetration of a 2 μm gold particle into the human dermis was developed and calibrated using experiments found in the literature. Using dimensional analysis, the model was linked to a larger scale steel ball-gelatin system in order to extract key material parameters for both systems and perform impact studies. In this manner, an elastic modulus of 2.25 MPa was found for skin, in good agreement with reported values from the literature. Further gelatin experiments were performed with steel, polymethyl methacrylate, titanium, and tungsten carbide balls in order to determine the effects of particle size and density on penetration depth. Both the finite element model and the steel-gelatin experiments were able to predict the penetration behavior that was found by other investigators in the study of the impact of typical particles used for vaccine delivery into the human dermis. It can therefore be concluded that scaled up systems utilizing ballistic gelatins can be used to investigate the performance of transdermal powder injection technology.
authors.affiliation: Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria St., Toronto, ON, Canada.
authors.forename: R A
authors.initials: RA
authors.lastname: Guha
authors.forename: N H
authors.initials: NH
authors.lastname: Shear
authors.forename: M
authors.initials: M
authors.lastname: Papini
mesh_terms: D000279:Administration, Cutaneous; D000497:Alloys; D001696:Biomechanical Phenomena; D001698:Biomedical Engineering; D016503:Drug Delivery Systems; D055119:Elastic Modulus; D020342:Finite Element Analysis; D044709:Forensic Ballistics; D005780:Gelatin; D006046:Gold / Q000008:administration & dosage; D006801:Humans; D007277:Injections, Jet; D008954:Models, Biological; D010316:Particle Size; D019904:Polymethyl Methacrylate / Q000008:administration & dosage; D011208:Powders / Q000008:administration & dosage / Q000737:chemistry; D012879:Skin Physiological Phenomena; D013232:Steel; D014025:Titanium / Q000008:administration & dosage; D017973:Tungsten Compounds / Q000008:administration & dosage
chemical_list: D000497:Alloys; D011208:Powders; D017973:Tungsten Compounds; C002802:tungsten carbide; D013232:Steel; C031462:titanium alloy (TiAl6V4); D006046:Gold; D005780:Gelatin; D019904:Polymethyl Methacrylate; D014025:Titanium