Systems and methods of using chemically bound antibiotics activated by infections
AssigneeOsteoceramics, Inc.
InventorThomas D. McGee
Life of this patent
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Abstract
Methods, devices and systems are disclosed for chemically bonding antibiotics to selected substrate materials which are not dissolved in normal physiological processes so that high local concentrations can be achieved during the inflammatory response. The antibiotics will remain permanently bonded to the substrate material until an infection occurs which releases the antibiotic in high concentrations to help control the infection. The high local concentrations may be much higher than systemic toxic levels, and can never reach toxic levels because the local dose is much less than needed to reach systemic toxicity if completely dissolved.
Claims13
A drug delivery system comprising:
- a biologically active antibiotic chemically bonded to a biologically active substrate with a chemical bond, the substrate adapted for insertion into a patient during a medical procedure, wherein the substrate comprises tricalcium phosphate and at least one of magnesium aluminate and calcium aluminate, and wherein the antibiotic is one of a tetracycline and a ciprofloxacin;
- wherein the substrate is insoluble in a normal physiological environment where no infection or inflammatory response is present and wherein the antibiotic remains inactive for pharmaceutical purposes as long as the substrate is insoluble;
- wherein at least a portion of the substrate becomes soluble and dissolves releasing the antibiotic from the substrate by breakage of the chemical bond upon the occurrence of a local infection near the substrate.
A method of using a drug delivery system, said method comprising:
- chemically bonding an antibiotic to a biologically active substrate with a chemical bond wherein the substrate comprises tricalcium phosphate and at least one of magnesium aluminate and calcium aluminate, and wherein the antibiotic is one of a tetracycline and a ciprofloxacin;
- wherein the substrate is insoluble in a normal physiological environment where no infection or inflammatory response is present and wherein the antibiotic remains inactive for pharmaceutical purposes as long as the substrate is insoluble;
- inserting the substrate into a patient during a medical procedure;
- wherein at least a portion of the substrate becomes soluble and dissolves releasing the antibiotic from the substrate by breakage of the chemical bond upon the occurrence of a local infection near the substrate.
A method of using a drug delivery system, said method comprising:
- chelating an antibiotic to an insoluble substrate, wherein the substrate comprises tricalcium phosphate and at least one of magnesium aluminate and calcium aluminate, and wherein the antibiotic is one of tetracycline and ciprofloxacin;
- wherein the antibiotic is inactive for pharmaceutical purposes while bonded to the substrate and while in a pH environment of between about 6.0 to 7.5;
- inserting the substrate into a patient during a medical procedure;
- wherein at least a portion of the substrate becomes soluble and dissolves releasing the antibiotic from the substrate when the pH near the substrate lowers to 5.0 or less during the presence of an infection or inflammatory response, whereby the antibiotic is thereby activated to fight the local infection.
A method of using a drug delivery system, said method comprising:
- chelating an antibiotic to an insoluble substrate, wherein the substrate comprises tricalcium phosphate and at least one of magnesium aluminate and calcium aluminate, and wherein the antibiotic is one of tetracycline and ciprofloxacin;
- wherein the antibiotic is inactive for pharmaceutical purposes while bonded to the substrate and while in a pH environment of between about 6.0 to 7.5;
- inserting the substrate into a patient during a medical procedure;
- wherein at least a portion of the substrate becomes soluble and dissolves releasing the antibiotic from the substrate by enzyme and humoral mechanisms in the presence of an infection or inflammatory response, whereby the antibiotic is thereby activated to fight the local infection.
Dependencies are inferred from the claim text.