| Biodegradable hydrophobic polysaccharide-based coatings -> Monitor Keywords |
|
|
  Biodegradable hydrophobic polysaccharide-based coatingsUSPTO Application #: 20070218102Title: Biodegradable hydrophobic polysaccharide-based coatings Abstract: Implantable medical articles having a coating formed of hydrophobic derivatives of natural biodegradable polysaccharides are described. The coatings can include a bioactive agent, and demonstrate desirable bioactive agent release profiles and can be prepared to have high drug loading. The coated implantable medical articles can be used to treat medical conditions, such as those requiring prolonged administration of the bioactive agent at a target location in the body. (end of abstract) Agent: Kagan Binder, PLLC - Stillwater, MN, US Inventors: Stephen J. Chudzik, Jeffrey J. Missling USPTO Applicaton #: 20070218102 - Class: 424426 (USPTO) The Patent Description & Claims data below is from USPTO Patent Application 20070218102. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED APPLICATIONS [0001]The present non-provisional Application claims the benefit of commonly owned provisional Application having Ser. No. 60/782,957, filed on Mar. 15, 2006, and entitled HYDROPHOBIC DERIVATIVES OF NATURAL BIODEGRADABLE POLYSACCHARIDES; and commonly owned provisional Application having Ser. No. 60/900,853, filed on Feb. 10, 2007, and entitled BIODEGRADABLE HYDROPHOBIC POLYSACCHARIDE-BASED DRUG DELIVERY IMPLANTS; which Applications are incorporated herein by reference in their entirety. TECHNICAL FIELD [0002]The present invention relates to biodegradable coatings for implantable medical articles. The method also relates to methods for treating medical conditions by releasing a bioactive agent from the coatings to a subject. BACKGROUND [0003]Coatings formed on the surface of medical devices have been shown to be beneficial as they can improve the properties of the device in one or more ways. As examples, coatings can provide the surface of implantable medical devices, such as catheters and stents, with lubricious, non-thrombogenic, biocompatible, and drug-delivery properties. Coatings providing one or more of these features can improve the function of the implanted device in the body. [0004]Site-specific drug delivery can be accomplished by injection and/or implantation of an article or device that releases the drug to the treatment site. Injection of drugs can have limitations, for example, by requiring multiple administrations, increasing risk of complications (such as infection), and patient discomfort. Implantation of a coated article or device that delivers drug to the treatment site via the coating has therefore gained much interest in recent years. [0005]For example, stents have been prepared with non-biodegradable coatings that include anti-proliferative compounds. These compounds can be released from the stents surface and minimizes the accumulation of smooth muscle cells on the stent surface, thereby providing an anti-restenotic effect. [0006]Generally speaking, a bioactive agent can be coupled to the surface of a medical device by surface modification, embedded, and released from within polymeric materials (matrix-type), or surrounded by and released through a carrier (reservoir-type). The polymeric materials in such applications should optimally act as a biologically inert barrier and not induce further inflammation within the body. However, the molecular weight, porosity of the polymer, a greater percentage of coating exposed on the medical device, and the thickness of the polymer coating can contribute to adverse reactions to the medical device. [0007]Drug-releasing biodegradable coatings formed from polylactic acid have been used to coat medical device surfaces (see, for example, U.S. Pat. No. 6,258,121). As the coating degrades, the bioactive agent is released from the surface of the device. These types of biodegradable materials, however, have the potential to degrade into products that cause unwanted side effects in the body by virtue of their presence or concentration in vivo. These unwanted side effects can include immune reactions, toxic buildup of the degradation products in the body, or the initiation or provocation of other adverse effects on cells or tissue in the body. If materials that are used to prepare the implant promote an adverse tissue response in the body, the effectiveness of the implant can be reduced. [0008]Several other challenges confront the use of medical devices or articles that release bioactive agents into a patient's body. For example, treatment may require release of the bioactive agent(s) over an extended period of time (for example, weeks, months, or even years), and it can be difficult to sustain the desired release rate of the bioactive agent(s) over such long periods of time. [0009]While advances in site-specific implantable drug delivery systems have been made, many systems do not release drug in a desired manner following implantation in a patient. For example, in many systems the majority of the drug present in the article is released from the device in an initial burst, resulting in premature depletion of the drug. Following this depletion, the drug may be delivered to the subject in sub-optimal amounts. [0010]In other systems, such as those based on polylactide-type biodegradable polymers, the majority of drug may be released at later points during the administration period due to bulk erosion of the drug containing biodegradable matrices. [0011]If drug is prematurely released from the implant, or not released until later, the duration of treatment or the rate of release may not be as long as desired. This can cause the implant to be therapeutically less effective. [0012]In addition, many drug delivery systems may demonstrate a great variation in the rate of drug release over the period of implantation. In these cases, an optimal rate of drug release may be seen only during a very small window over the period of implantation. SUMMARY OF THE INVENTION [0013]Generally, the present invention relates to implantable medical articles that include a biodegradable coating. The coating comprises a matrix of hydrophobic derivatives of natural biodegradable polysaccharides (also referred to herein as "hydrophobic polysaccharides"). [0014]In some aspects, the coating includes a bioactive agent, which can be released from the coating after the implantable medical article is placed within a subject. The present invention also relates to treating medical conditions using medical articles having biodegradable coatings formed of the hydrophobic polysaccharides. [0015]Coating compositions including hydrophobic polysaccharides adhere well to the surface of medical articles to which they are applied, and form coatings with properties that are desirable for use in the body. The biodegradable coatings of the invention are shown herein to demonstrate one more of the following properties, such as compliance, conformability, and/or durability, which provide(s) benefits for in vivo use. These properties can prevent or minimize cracking, delamination, and/or abrasion of the coating when the coated medical article is manipulated during steps in involving placement of the coated article in the body. [0016]The hydrophobic polysaccharides can be used in combination with various coating solvents, allowing the preparation of compositions that can be suitably mixed with a variety of excipients or bioactive agents. The coating compositions can also be prepared having a high concentration of solids, allowing the formation of, in some embodiments, a coating having a high content of bioactive agent. The coating materials can also be readily applied to surfaces of implantable medical articles using conventional coating methods, such as spray coating and dip coating. [0017]The matrix of hydrophobic polysaccharides that form the coating can be degraded into natural materials, which in turn improve the compatibility of the device. Degradation of the coating can result in the release of, for example, naturally occurring mono- or disaccharides, such as glucose, which are common serum components. This provides an advantage over coatings formed from polyglycolide-type molecules, which can degrade into products that cause unwanted side effects in the body by virtue of their presence or concentration in vivo. [0018]In some aspects, the invention provides an implantable medical article comprising a biodegradable bioactive-agent releasing coating. The coating comprises a matrix of hydrophobic derivatives of natural biodegradable polysaccharides and bioactive-agent within the matrix, and the coating is capable of releasing bioactive agent following placement of the medical article in a subject. [0019]Preferably, the coatings of the present invention include hydrophobic derivatives of lower molecular weight natural biodegradable polysaccharides, wherein the hydrophobic derivatives have a molecular weight of about 500,000 Da or less. Even more preferably hydrophobic derivatives having a molecular weight of about 100,000 Da or less, 50,000 Da or less, 25,000 Da or less, or in the range of 2000 Da to about 20,000 Da, or in the range of 4000 to 10,000 Da, are used to form the coating. [0020]In some aspects, the coatings are formed from low molecular weight hydrophobic derivatives of .alpha.-1,4 glucopyranose polymers. For example, the implants can be formed from a polymer selected from hydrophobic derivatives of maltodextrin, polyalditol, amylose, and cyclodextrin polymers. In some aspects the hydrophobic derivative is a non-cyclic glucopyranose polymer. In some aspects the hydrophobic derivative is a linear glucopyranose polymer. Continue reading... Full patent description for Biodegradable hydrophobic polysaccharide-based coatings Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Biodegradable hydrophobic polysaccharide-based coatings patent application. Patent Applications in related categories: 20080206308 - Hydrogel porogents for fabricating biodegradable scaffolds - Hydrogel microparticles with entrapped liquid are used as the porogen to reproducibly form interconnected pore networks in a porous scaffold. In one embodiment, a biodegradable unsaturated polymer, a crosslinking agent, and a porogen comprising biodegradable hydrogel microparticles are mixed together and allowed to form a porous scaffold in an mold ... ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Biodegradable hydrophobic polysaccharide-based coatings or other areas of interest. ### Previous Patent Application: Bone formation agent and method of production Next Patent Application: Rate controlled release of a pharmaceutical agent in a biodegradable device Industry Class: Drug, bio-affecting and body treating compositions ### FreshPatents.com Support Thank you for viewing the Biodegradable hydrophobic polysaccharide-based coatings patent info. IP-related news and info Results in 2.75625 seconds Other interesting Feshpatents.com categories: Software: Finance , AI , Databases , Development , Document , Navigation , Error |
||
