**9. Outlook of plasma drug delivery**

**Figure 13.** Variations of TEWL values before and after microplasma irradiation, tape striping test and plasma jet irradi-

**8. Improvement of galantamine hydrobromide (GaHBr) permeation by**

Galantamine hydrobromide (GaHBr) (**Figure 14**) is an alkaloid, isolated from plant species such as Narcissus and Lycoris species [93]. Treatment of Alzheimer's disease occurs by inhibition of acetylcholinesterase enzyme. The chemical structure of galantamine hydrobro-

ation [72].

**plasma irradiation**

126 Advanced Technology for Delivering Therapeutics

mide is shown in **Figure 14**.

**Figure 14.** Chemical structure of galantamine hydrobromide.

Plasma as a source of UV light, heat, ions, reactive radicals and metastable states could be a successful tool for transdermal drug delivery. Each of these parameters can be used for improvement of skin permeability. Stratum corneum can be altered by chemical reaction of reactive oxygen species or by UV causing peroxidation of intercellular lipids. Undesirable heating effects can be tuned by the length of the plasma pulse and then a change of the conformation of lipids can be achieved also by increasing gas temperature in plasma. Improvement of permeability of skin by plasma was proved by ATR-FTIR and TEWL methods. A plasma jet is effective in etching of stratum corneum but can cause damage to skin because of the presence of a high electric field. We believe that plasma jet could be considered as a trade-off relationship, i.e. accompanied by physical damage or pain on the skin, similar to needles and creation of pores can cause risk of infection. On the other hand, microplasma seems to be more suitable for future drug delivery because it caused lower damage of skin. Transdermal drug delivery of galantamine hydrobromide by microplasma showed slight improvement in comparison with passive diffusion but further investigation is needed for drug testing or improvement in plasma properties in the future. We suggest that the use of a transdermal drug delivery with plasma irradiation is feasible, and thus, could be combined with appropriate drugs to target various symptoms such as Alzheimer's disease, diabetes and other symptoms that cannot be cured by applying plasma irradiation alone. This novel method will reveal new directions for the future of plasma medicine. Our aim is to combine a safe transdermal drug delivery method with a transdermal agent such as a peptide vaccine without requiring an injection needle and causing physical damage to the skin. Safety of patients, without causing harmful damage or physical damage to the skin, is critical for enabling this novel technology.
