Method of drug delivery to interstitial regions of the myocardium - Patents

Method of drug delivery to interstitial regions of the myocardium

Agent: Crockett & Crockett - Laguna Hills, CA, US
Inventor: Peter A. Altman
Class: 600007000 (USPTO), (Intl Class)
#20060020158
01/26/06
A method of treating the heart and other body tissues by injecting a compound comprised of microsphere encapsulated macromolecule therapeutic agents into the myocardium, such that the microsphere size inhibits capillary transport of the compound but may permit lymphatic transport of the compound, and the compound releases therapeutic agents upon degradation of the microsphere.
FIELD OF THE INVENTION
[0002] The present invention relates to the interstitial delivery of particulate drug delivery systems for large and small molecule therapeutic agents within the heart.
SUMMARY
[0007] The therapeutic compounds described below comprise very small capsules which can be injected into body tissue, particularly the heart. The capsules include an encapsulating layer which surrounds a therapeutic agent. After injection, the encapsulating layer degrades or dissolves, and the therapeutic agent is released within the heart. The therapeutic agent may be one of any number of known agents such as anti-arrhythmic drugs, gene therapy solutions, and macromolecules intended to have either acute or long-term effects on the heart. While some of these therapeutic agents are used to treat the heart by injecting them into the heart, they are of such small size that they readily enter the cardiac capillary system and the cardiac lymphatic system, and are quickly transported away from the injection site. Thus, in prior treatment methods, relatively large doses and repeated dosed are required to provide therapeutic effect at the injection site. To provide a solution to this problem, the capsules described below are provided in sizes that are too large to permit capillary transport or lymphatic transport. Thus, injected capsules are immobile within the heart tissue, and upon degradation they will release a therapeutic agent very near the site of injection. The capsules may also be provided in sizes that are too large to permit capillary transport, but small enough to enter the lymphatic system and be transported away from the injection site in the cardiac lymphatic system, so that the therapeutic effect is provided at some distance from the injection site. The encapsulating layer may be made from various materials including biodegradable polymers in the form of microspheres, or from standard vesicle forming lipids which form liposomes and micelles.
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