Electroporation Parameters for Successful Transdermal Delivery of Insulin

This work investigates the effects of electroporation parameters on the transdermal delivery of insulin. Electroporation (EP) is known to induce temporal pores in the membrane, which are expected to enhance the diffusion of insulin through rabbits' skin. For such purpose, 5 different formulations of insulin and enhancers are applied to rabbit groups (5 rabbits each) with induced hyperglycemia in the presence of electroporative pulses. The blood sugar level (BSL) is followed up to 5-hour duration starting from the administration of the hyperglycemia-inducing factor. The effect of different electroporation parameters on BSL of rabbits is examined and compared with control groups. Results show that the increase in the number of pulses (from 15 up to 60 successive pulses) at an insulin concentration of 50 IU/mL, the increase in insulin concentration (from 50 to 70 IU/mL), and the decrease in applied field strength (from 200 to 100 V/cm) result in a significant decrease in BSL compared with control. Among all of the investigated formulations, the best performance is recorded for the insulin solution + EP (without enhancers) in almost all of the studied experimental conditions.

Iontophoresis: principles and applications

Introduction Iontophoresis is a noninvasive technique used to increase transdermal penetration of substances through the skin layer (epidermis, dermis and hypodermis) in a controlled manner. Technological advance in recent decades have provided reduced cost of equipment needed for implementation, which allowed for the expansion of this technique. Objective The aim of this paper is to present the state of the art on iontophoresis, ranging from the atomic characteristics of the ion formation to the current applications of the technique. Methods Were researched papers from databases: IOP publishing, ScienceDirect, Pubmed, Springer, IEEE Xplore, Google Scholar and books with keywords iontophoresis, ions, topical applications between 1967 and 2010. Results Were selected (number of papers and database) 1 IOP Publishing, 1 from ScienceDirect, Central, 1 from Springer, 2 from PubMed, 11 from IEEE Xplore, 35 from Google Scholar, and 15 books, totaling 66 references and websites with nationally marketed electrotherapy products. Conclusion Iontophoresis is suitable for applications such as acetic acid (calcific tendinitis and myositis ossificans), calcium chloride and magnesium sulfate (control of musculoskeletal spasms), dexamethasone (inflammation), lidocaine (inflammation of soft tissues), zinc oxide (rheumatoid arthritis). It is also used in cosmetic applications with devices attached to the skin and for eye treatment aimed at specific tissues of the eye, providing a treatment option for various eye diseases, reducing the complications secondary to traditional methods of treatment. The advantages are the significant increase in the release and control of therapeutic agents, including drugs with high molecular weight. The disadvantages of iontophoresis are the complexity of the drug release system and prolonged exposure of the skin to an electrical current.