Developing a commercial air ultrasonic ceramic transducer to transdermal insulin delivery

The application of low‑frequency ultrasound for transdermal delivery of insulin is of particular public interest due to the increasing
problem of diabetes. The purpose of this research was to develop an air ultrasonic ceramic transducer for transdermal insulin delivery
and evaluate the possibility of applying a new portable and low‑cost device for transdermal insulin delivery. Twenty‑four rats were
divided into four groups with six rats in each group: one control group and three experimental groups. Control group (C) did not receive
any ultrasound exposure or insulin (untreated group). The second group (T1) was treated with subcutaneous insulin (Humulin® R, rDNA
U‑100, Eli Lilly and Co., Indianapolis, IN) injection (0.25 U/Kg). The third group (T2) topically received insulin, and the fourth group (T3)
received insulin with ultrasound waves. All the rats were anesthetized by intraperitoneal injection of ketamin hydrochloride and xylazine
hydrochloride. Blood samples were collected after anesthesia to obtain a baseline glucose level. Additional blood samples were taken
every 15 min in the whole 90 min experiment. In order for comparison the changes in blood glucose levels” to “ In order to compare
the changes in blood glucose levels. The statistical multiple comparison (two‑sided Tukey) test showed a significant difference
between transdermal insulin delivery group (T2) and subcutaneous insulin injection group (T1) during 90 min experiment (P = 0.018).
In addition, the difference between transdermal insulin delivery group (T2) and ultrasonic transdermal insulin delivery group (T3) was
significant (P = 0.001). Results of this study demonstrated that the produced low‑frequency ultrasound from this device enhanced the
transdermal delivery of insulin across hairless rat skin.