Affiliations: [a] Department of Mechanical Engineering, Faculty of
Engineering, Yamaguchi University, Tokiwadai 2-16-1, Ube, Yamaguchi, 755-8611,
Japan | [b] College of Pharmaceutical and Biological Engineering,
Chongqing University of Technology, Xingsheng road 4, Yangjiaping, Chongqing,
400050, China
Abstract: Liposomes as a drug delivery system have been an attracting interest
to many researchers. This paper concerns with the study on how to control the
release rate of the inner-substances from liposomes by the ultrasonic
irradiation. Two kinds of ultrasonic control methods are tested for
investigation of the efficiency of the release property of the liposomes. One
control method is to increase the input power by fixing its frequency at a
frequency near the probe resonant frequencies. Another method is to adjust the
input frequency around the probe resonant frequencies but fixing the input
power. In the experiments, three kinds of liposomes with different lipid ratio
were prepared and calcein as an indicator was enclosed into the liposomes. The
release effect was evaluated from the fluorescence intensity changes which was
measured by a spectrofluorometer. The results showed that the efficient release
property could be achieved both by control of the input power and the input
frequency, but adjusting the input frequency around the probe resonant
frequency can get higher efficient release performance than that controlled by the input power.
Keywords: Drug delivery system, liposome, release control, ultrasonic irradiation, resonant frequency
