Method for making self-assembling diketopiperazine drug delivery system
First Claim
1. A microparticulate system for drug delivery comprising:
- diketopiperazine microparticles, wherein the microparticles are stable at a first defined pH due to association and precipitation of the diketopiperazines and unstable at a second defined pH due to dissociation of the diketopiperazines, andwherein the diketopiperazine has the general structure ##STR3## Wherein n is between 0 and 7, Q is, independently, a C1-20 straight, branched or cyclic alkyl, aralkyl, alkaryl, alkenyl, alkynyl, heteroalkyl, heterocyclic, alkyl-heterocyclic, or heterocyclic-alkyl;
T is --C(O)O, --OC(O), --C(O)NH, --NH, --NQ, --OQO, --O, --NHC(O), --OP(O), --P(O)O, --OP(O)2, --P(O)2 O, --OS(O)2, or --S(O)3 ;
U is an acid group, a basic group or a zwitterionic C1-2 0 chain containing at least one acidic group and at least one basic group, wherein the side chains can be further functionalized with an alkene or alkyne group at any position, one or more of the carbons on the side chain can be replaced with an oxygen, one or more of the carbons can be functionalized with an acidic or basic group, and wherein the ring atoms X at positions 1 and 4 are either O or N.
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Abstract
Drug delivery systems have been developed based on the formation of diketopiperazine (or analogs) microparticles. In the preferred embodiment the microparticle is stable at low pH and disintegrates at physiological pH, and is particularly useful for oral drug delivery. In other embodiments, the microparticles are stable at high pH and disintegrate at neutral or basic pH, or are stable at neutral pH and disintegrate at high or low pH. In the most preferred embodiment the microparticles are formed in the presence of the drug to be delivered, for example, insulin, felbamate, calcitonin or heparin. The diketopiperazine synthetic intermediates are preferably formed by cyclodimerization to form diketopiperazine derivatives at elevated temperatures under dehydrating conditions, functionalized on the side chains, and then precipitated with drug to be incorporated into microparticles.
318 Citations
28 Claims
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1. A microparticulate system for drug delivery comprising:
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diketopiperazine microparticles, wherein the microparticles are stable at a first defined pH due to association and precipitation of the diketopiperazines and unstable at a second defined pH due to dissociation of the diketopiperazines, and wherein the diketopiperazine has the general structure ##STR3## Wherein n is between 0 and 7, Q is, independently, a C1-20 straight, branched or cyclic alkyl, aralkyl, alkaryl, alkenyl, alkynyl, heteroalkyl, heterocyclic, alkyl-heterocyclic, or heterocyclic-alkyl;
T is --C(O)O, --OC(O), --C(O)NH, --NH, --NQ, --OQO, --O, --NHC(O), --OP(O), --P(O)O, --OP(O)2, --P(O)2 O, --OS(O)2, or --S(O)3 ;
U is an acid group, a basic group or a zwitterionic C1-2 0 chain containing at least one acidic group and at least one basic group, wherein the side chains can be further functionalized with an alkene or alkyne group at any position, one or more of the carbons on the side chain can be replaced with an oxygen, one or more of the carbons can be functionalized with an acidic or basic group, and wherein the ring atoms X at positions 1 and 4 are either O or N. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 13)
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10. A method for making a microparticulate system for drug delivery comprising:
forming diketopiperazines in a solution with a first defined pH, adding a solution having a second defined pH, and precipitating the diketopiperazines to form microparticles, wherein the diketopiperazine has the general structure ##STR4## Wherein n is between 0 and 7, Q is, independently, a C1-20 straight, branched or cyclic alkyl, aralkyl, alkaryl, alkenyl, alkynyl, heteroalkyl, heterocyclic, alkyl-heterocyclic, or heterocyclic-alkyl;
T is --C(O)O, --OC(O), --C(O)NH, --NH, --NQ, --OQO, --O, --NHC(O), --OP(O), --P(O)O, --OP(O)2, --P(O)2 O, --OS(O)2, or --S(O)3 ;
U is an acid group, a basic group or a zwitterionic C1-20 chain containing at least one acidic group and at least one basic group, wherein the side chains can be further functionalized with an alkene or alkyne group at any position, one or more of the carbons on the side chain can be replaced with an oxygen, one or more of the carbons can be functionalized with an acidic or basic group, and wherein the ring atoms X at positions 1 and 4 are either O or N.- View Dependent Claims (11, 12, 14, 15, 16, 23, 24, 25)
- 17. A method for administering a biologically active agent to a patient comprising providing the agent selected from the group consisting of proteins, peptides, polysaccharides, lipids, lipopolysaccharides, nucleic acids and other biologically active organic molecules, imaging agents, and cell specific targeting agents, in combination with microparticles formed of diketopiperazines, wherein the microparticles are stable at a first defined pH due to association and precipitation of the diketopiperazines and unstable at a second defined pH due to dissociation of the diketopiperazines.
Specification