1 Technical Parmeters

2 Principle

Ultrasound introduction of drugs is a kind of treatment method of transdermal drugs. Under the action of ultrasound, it can play a better role in pharmacodynamics.

Because 90% of the dermis of the skin is vascular-rich connective tissue, drugs penetrate into subcutaneous tissue such as dermis through the epidermis. Driven by active blood circulation, drugs will be absorbed by the body quickly. The greatest characteristic of percutaneous absorption of drugs can not only avoid the damage of intestine, stomach and liver caused by drugs, but also avoid the possible intestinal and gastric inactivation of active ingredients of drugs through the digestive tract and the first-pass effect of the liver, so as to improve the availability of drugs. Therefore, drug transdermal absorption is not only a hot topic in pharmaceutical research, but also a hot topic in clinical treatment research.

It is precisely because of the safety and effectiveness of drug transdermal absorption that many adverse reactions can be reduced. Therefore, in recent years, there have been many drugs absorbed through the skin and physical methods and equipment to promote skin absorption. In order to improve the effect of drug transdermal absorption, two aspects should be considered: one is to improve the ability of drug transdermal penetration; the other is to improve the body's ability to absorb drugs.

In order to improve the transdermal penetration of drugs, we adopted the following technical measures:

1. Using fine chemical technology, the drug is made into a modern cosmetics form, which has surface activity and good water retention. Because surfactants can increase the permeability of epidermal lipid membranes to drugs, which can promote the diffusion of drugs; because the water content of cuticle is increased, the cuticle can expand into a porous state and be easily penetrated by drugs.

2. Mechanochemistry and nanotechnology can refine drug particles close to nano-scale, degrade drug macromolecules properly, and combine drug molecules with water molecules into hydrated state, especially to form self-organized nano-microcapsules. These forms of drugs not only further improve the penetration and diffusion ability of drugs, but also increase the skin surface temperature due to hydration, thus speeding up blood circulation and reducing the activation energy barrier of biochemical reactions between drugs and organisms.

3. Natural transdermal agents with good effect were selected. In order to improve the transdermal permeability of drugs, some synthetic transdermal agents such as dimethyl sulfoxide and azone are often added. However, experiments show that some natural transdermal agents not only have better transdermal effect, but also have higher safety. In our products, we add a certain proportion of traditional Chinese medicine transdermal agent.

In order to improve the body's absorption capacity of drugs, it is often through the mechanical effect of massage, the thermal effect of ironing or infrared ray, the electrical effect of improving the body's dielectric properties by electromagnetic field and the introduction of ultrasound to improve the body's absorption capacity of drugs. Because of the effect of ultrasound on the body, it embodies many effects such as mechanical, electrical, thermal and ultrasonic holes, so it has a good introduction of drugs and absorption effect of the body. Ultrasound is widely used because of its wide application, easy operation and mastery.

The introduction of drugs by ultrasound relies on the biological effects of ultrasound on organisms and cells. The biological effects, i.e. the permeability and material exchange capacity of cell membranes, are closely related to the structural characteristics of cell membranes, their mechanical properties and electrical properties.

Cells are the basic units of biological morphology and activity. Cell membrane is the mechanism that separates the protoplasm from the outside of the cell, and is also the place where the cell exchanges material, energy and information with the outside. Therefore, the key to the absorption of drugs by the body is that drug molecules can cross cell membranes and run smoothly between cells.

Cell membrane is composed of lipid bilayer as matrix. The hydrophilic end (polarity) of the bilayer is toward the outer side of the membrane, and the hydrophobic end (non-polarity) is toward the center of the membrane. The bilayer has a liquid substance with a viscosity similar to light oil and can flow. Cell membranes have formed structures because they are surrounded by water phase substances. The hydrophilic end of the amphiphilic molecule binds to the hydrogen bond of the water molecule and forms an electrostatic attraction, while the hydrophobic end attracts and compacts each other, so that the material layer can form a membrane and maintain a fixed skeleton. Because the water molecules around the bilayer keep moving randomly, the attraction of hydrophilic end and the mutual absorption of hydrophobic end also change randomly.

It is precisely due to the formation of the above structure that the cell membrane has a certain electrostatic potential, about 70-90 mv, and the electric field intensity in the cell membrane is about 107 v/m, which can form the pressure from the two surfaces of the membrane to the inside of the membrane, and its stress is about - 104pa. Cell membranes, like other biological tissues, are not only dielectrics with certain dielectric constants, but also piezoelectric. Therefore, under the action of alternating stress, not only their mechanical properties and structures will change periodically, but also their electrical properties, such as membrane resistance, membrane potential, polarizability, dielectric constant and conductivity. Rates and so on all have periodic changes.

When ultrasonic wave propagates in different media, it can make the particles of medium produce mechanical high-frequency vibration, and produce certain thermal effect and cavitation effect in liquid. However, if the frequency is high and the power is low, the cavitation effect which can cause the mechanochemical reaction will not be obvious. When ultrasonic wave propagates in different media, it has different damping, among which air has the greatest damping. Ultrasound refracts at the interface when it propagates in different media.