Title:  Cyclodextrin flavor delivery systems

United States Patent:  6,287,603

Assignee:  Nestec S.A. (Vevey, CH)

Filed:  September 16, 1999

The invention relates to a process for preparing cyclodextrin inclusion complexes that increases the efficiency of the complexation so that a higher percentage of the active is recovered as a cyclodextrin inclusion complex. The process involves adding a cyclodextrin to a solvent in a reaction vessel, adding an active to the cyclodextrin solution with stirring, and allowing the mixture to stir for an appropriate amount of time and at a sufficient temperature to form an inclusion complex between the cyclodextrin and the active. A solids content increasing agent such as gum acacia, maltodextrin, modified dextrins, or mixtures thereof, is then added to the solution to increase the total solids content of the solution and the solution is at 25^oC. and 40^oC. and relative humidity of 53 percent dried to recover the cyclodextrin-active inclusion complex as a dry powder with the amount of active in the powder ranging from 1 to 20 percent by weight of the complex. The invention also relates to cyclodextrin inclusion complexes prepared by this process.

SUMMARY OF THE INVENTION

The present invention relates to new higher loading cyclodextrin inclusion complexes containing one or more actives and to a process for preparing such complexes. The process comprises the steps of dissolving cyclodextrin in a solvent in a reaction vessel to form a first solution, adding the one or more actives to the first solution with stirring to form a second solution of the one or more actives and cyclodextrin, stirring the second solution for a sufficient amount of time and at a sufficient temperature to form inclusion complexes between the cyclodextrin and the one or more actives, adding a solids content increasing agent to the second solution to increase the solids content of the second solution and form a third solution, and drying the third solution to form the cyclodextrin inclusion complex as a dry powder.

The concentration of cyclodextrin in the second solution may be between about 5 and 40 percent and the ratio of active to cyclodextrin may be between about 0.001:1 and 100:1. The temperature of the second solution may be between about 4^oC. and 75^oC.

In one embodiment of the process the reaction vessel is sealed and the active is added without opening the reaction vessel. The reaction vessel may also be pressurized. The reaction vessel may be pressurized to a value of above atmospheric to about 1000 psi.

In another embodiment of the process, the second solution is stirred at a first temperature for a first length of time, the temperature of the second solution is then progressively lowered to one or more subsequent temperatures, and the lowered temperature of the second solution is maintained while the second solution is stirred.

The solids content increasing agent is preferably at least one of gum acacia, maltodextrin, or modified starch, and may be added to increase the solids content of the second solution to about 30 to 55 percent by weight of the solution. The solids content of the second solution may conveniently be increased by adding gum acacia in an amount of about 5 to 20 percent by weight of the solution and the remaining solids content increased by adding about 40 to 60 percent by weight of the solution of a maltodextrin having a dextrose equivalent of between about 5 and 10.

The active may be one or more pharmaceuticals, perfumes, or flavor components. Preferably, the flavor component can be dimethyl sulfide, methyl mercaptan, acetaldehyde, 2-methyl-3-furanthiol, diacetyl, flavors produced by pyrolysis, or mixtures thereof.

The invention also relates to cyclodextrin inclusion complexes prepared according to the process of the invention. The cyclodextrin inclusion complex may contain between about 1 and 20 percent by weight of the complex, and conveniently is above 15 percent by weight of complex. As noted above, the active in the cyclodextrin inclusion complex may be one or more flavors, perfumes, or pharmaceuticals.

Claim 1 of 20 Claims

What is claimed is:

1. A process for preparing cyclodextrin inclusion complexes of one or more actives comprising the steps of:

dissolving cyclodextrin in a solvent in a reaction vessel to form a first solution;

adding one or more actives to the first solution with stirring to form a second solution of the one or more actives and cyclodextrin;

stirring the second solution for a sufficient amount of time and at a sufficient temperature to form inclusion complexes between the cyclodextrin and the one or more actives;

adding a solids content increasing agent to the second solution to form a third solution having an increased solids content; and

drying the third solution to form dry powder cyclodextrin inclusion complexes containing the actives in an amount of about 1 to 20 percent by weight of the complex.

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