# Ultrasound Mediated Transdermal Drug Delivery

## Ultrasound Mediated Transdermal Drug Delivery

• Submitted By: laurapm
• Date Submitted: 11/14/2011 6:16 AM
• Category: Science
• Words: 697
• Page: 3
• Views: 354

INTRODUCTION

* Transdermal drug delivery is a method of transporting medication into the human body through the skin.
Benefits:
* Avoid first pass effect
* User-friendly method
* Avoid spread of diseases

* The skin is resistant to substances entering or coming out of the body.
* Ultrasound increases skin permeability when applied to the skin with a coupling medium.
* Surfactants have been shown to greatly increase skin permeability when used in conjunction with ultrasound.

PROBLEM: Exact mechanism is unknown.
*

OBJECTIVES
* This project aims to design and build an “Acoustic Fish” in order to study the behaviour of bubbles when exposed to their resonance frequency and especially when different surfactants are added.

* By constructing this device, the bubble response can be recorded using a high speed camera and the results can be analysed.

* Analysis of results will make it possible to correlate bubble behaviour to ultrasound mediated transdermal drug delivery with the use of surfactants as a coupling medium.

WHAT IS AN “ACOUSTIC FISH”?

An “Acoustic Fish” consists of a clear recipient filled up with water.
A tube is placed inside the tank and connected to a syringe filled with air.
When the syringe is pushed forward, an air bubble is created inside the tank.
A sound source is put in contact with the tank and connected to a frequency tone generator.
Different frequencies are played around the bubble’s resonance frequency.
A high speed camera is used to record the response of the bubble.

THEORY AND CALCULATIONS
1. The resonance frequency of the bubble needs to be calculated:

Minnaert resonance theory enables the calculation of the resonance frequency of a spherical bubble using the following equation:
2πf=3γpoρR02

f=2.774847×1R0 R0=1.985 mm f≈1400 Hz

2. A spherical bubble needs to be created at the end of the tube submerged in the tank. It...