Physicochemical modulation of skin barrier by microwave for transdermal drug delivery.
OBJECTIVE
To investigate mechanism of microwave enhancing drug permeation transdermally through its action on skin.


METHODS
Hydrophilic pectin-sulphanilamide films, with or without oleic acid (OA), were subjected to drug release and skin permeation studies. The skins were untreated or microwave-treated, and characterized by infrared spectroscopy, Raman spectroscopy, thermal, electron microscopy and histology techniques.


RESULTS
Skin treatment by microwave at 2450 MHz for 5 min promoted drug permeation from OA-free film without incurring skin damage. Skin treatment by microwave followed by film loaded with drug and OA resulted in permeation of all drug molecules that were released from film. Microwave exerted spacing of lipid architecture of stratum corneum into structureless domains which was unattainable by OA. It allowed OA to permeate stratum corneum and accumulate in dermis at a greater ease, and synergistically inducing lipid/keratin fluidization at hydrophobic C-H and hydrophilic O-H, N-H, C-O, C=O, C-N regimes of skin, and promoting drug permeation.


CONCLUSIONS
The microwave technology is evidently feasible for use in promotion of drug permeation across the skin barrier. It represents a new approach in transdermal drug delivery.
Non-Destructive Biomedical and Pharmaceutical Research Centre, Universiti Teknologi MARA, 42300 Puncak Alam, Selangor, Malaysia. wongtinwui@salam.uitm.edu.my
Tin Wui
TW
Wong
Anuar
A
Nor Khaizan
D000279:Administration, Cutaneous; D000818:Animals; D016503:Drug Delivery Systems / Q000295:instrumentation*; D004867:Equipment Design; D008297:Male; D008872:Microwaves; D019301:Oleic Acid / Q000737:chemistry; D010368:Pectins / Q000737:chemistry; D014677:Pharmaceutical Vehicles / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D012867:Skin / Q000378:metabolism* / Q000528:radiation effects* / Q000648:ultrastructure; D012869:Skin Absorption / Q000528:radiation effects*; D013424:Sulfanilamides / Q000008:administration & dosage* / Q000493:pharmacokinetics
D014677:Pharmaceutical Vehicles; D013424:Sulfanilamides; D019301:Oleic Acid; D010368:Pectins