A kind of drug coating and preparation method thereof

Abstract

The invention relates to a drug coating, comprising: a bottom layer, the bottom layer includes biodegradable polymers with amino groups or protonated amino groups; the bottom layer is arranged on the surface of medical devices; Sexual compounds and degradable polymers with carboxyl or carboxylate groups; the surface layer is coated on the surface of the bottom layer and does not completely cover the bottom layer; drugs, the drugs are only contained in the surface layer or contained in the bottom layer at the same time and in the surface layer. The drug coating has a strong binding force with the surface of the medical device, which can effectively reduce drug loss during device delivery, improve the transfer amount, consistency and retention time of the drug to the mucosa, prolong the drug release period, and improve bioavailability. At the same time, the drug coating can activate the coagulation effect at the bleeding site in the injured area, which is conducive to the adhesion and growth of cells in the injured area, and promotes healing.

Description

technical field [0001] The invention relates to the field of medical devices, in particular to a drug coating and a preparation method thereof. Background technique [0002] It is becoming more and more to treat various medical diseases by implanting or intervening medical devices into the vascular and luminal system of the patient's body. In particular, it is more and more common to use medical devices to treat local diseases with targeted drugs, such as drug stents, drug balloon catheters, etc. [0003] In the past few years, a large number of medical devices carrying drugs have been developed, among which drug stents are currently one of the most commonly used and most effective drug-containing medical devices. The stent is mixed with a drug and a polymer matrix and coated on the surface of the stent to form a local slow drug release system. When the stent is implanted in the blood vessel, esophagus, biliary tract or other lumens, the drug will be slowly released for sev...

AI Technical Summary

Problems solved by technology

The water-soluble small molecule carrier has the following disadvantages: first, because the molecular weight of the water-soluble small molecule is small (<1000D), the mechanical strength of the coating is weak, the film-forming effect is poor, and the affinity with the balloon surface is poor, and the drug coating The binding force between the layer and the balloon is weak, and the drug is prone to serious shedding and loss during the delivery process to the target lesion, which affects the consistency of the drug transfer amount during the full contact between the balloon and the lesion, and easily forms an "empty window". "area (the drug coating is completely lost in some areas on the surface of the balloon), which affects the clinical treatment effect

Second: Since the molecular weight of the water-soluble small molecule carrier is often the same order of magnitude or even smaller than that of the drug, in the case of a large difference in hydrophilicity between the carrier molecule and the drug (the HLB value of the water-soluble small molecule is often >10), it is easy to cause The phase separation phenomenon occurs in the drug coating, the drug dispersion effect is not good, the coating uniformity is poor, and the process stability control is difficult in large-scale production

Third, water-soluble small molecules are transferred to the mucosal surface with weak adhesion strength, short adhesion time, easy to be washed away or dissolved by blood or tissue fluid, difficult to achieve long-term drug release effect, and low bioavailability

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