Study On Percutaneous Penetration Of Drugs By Low Frequency Ultrasound

Diclofenac sodium is a common analgesic anti-inflammatory drug,commonly used in the clinical treatment of arthritis,rheumatism and other common acute attack or persistent pain.Traditional oral,injectable methods tend to cause gastrointestinal discomfort and side effects,therefore,it is urgent to find an effective and safe drug delivery method.As an important method of transdermal administration,ultrasonic exhalation method has the advantages of noninvasive,noninvasive drug resistance,safe and effective,and has been extensively studied in recent years.Ultrasound can disrupt the lipid bilayer structure in keratinocytes,increase the permeability of the skin and increase the transmittance of the drug.At present,most of the studies on low-frequency ultrasound penetration are in vitro transdermal permeation experiments,and ultrasound percutaneous drug related to the relevant theoretical research less,especially from the numerical study of ultrasonic frequency and promote the relationship between the effect of less.In order to enrich this research,this paper mainly carried out the following research:1.Based on the theory of ultrasonic penetration,the cavitation effect of ultrasonic wave and the kinetics of cavitation bubble generated by ultrasonic wave are studied emphatically.The relationship between ultrasonic frequency and cavitation bubble motion is discussed,and the motion equation is solved by MATLAB and the simulation of the state of motion.2.The simulation results of different ultrasonic frequencies are analyzed,and the effect of ultrasonic frequency on ultrasonic penetration is discussed theoretically.It is proved that the effect of low frequency ultrasound on drug penetration is better.3.Based on the above theoretical research,low frequency ultrasound was designed to promote the transdermal permeation of diclofenac sodium in vitro.Using a modified Franz diffusion cell,the accumulated permeation per unit area of diclofenac sodium through the rat skin was measured by UV-visible spectrophotometer.A low-frequency ultrasound was employed to enhance the percutaneous penetration.The influence of ultrasonic parameters on the promoting effect of diclofenac sodium was studied.The experimental results are obtained that low-frequency ultrasound could significantly promote the percutaneous penetration of diclofenac sodium,and the penetration effect becomes more significant with the increasing duration of ultrasonic in 5 min.when the coupling medium was normal saline and the duration time was 5 min,the cumulative infiltration of diclofenac sodium was 3.02 times of passive diffusion within 5 h.4.Comparison of the effect of continuous and pulsed ultrasound on transdermal permeation of diclofenac sodium under the same conditions.There was no significant difference in the effect of the two modes of administration(P>0.05).However,considering the risk of skin damage,it is recommended to use pulsed ultrasound mode.