Crystalline form of sucralose, and method for producing it

Abstract

A crystalline form of sucralose, and a method of making it. The method involves continuously crystallizing sucralose from an aqueous solution by a process providing continuous removal and recirculation of the vessel contents, and providing a long residence time for sucralose in the system. The crystals thus formed are of a relatively low length / diameter ratio, have an unsymmetrical shape, and exhibit good stability. The larger crystals in particular are tapered as compared to the rod-like larger crystals in prior art product.

Description

FIELD OF THE INVENTION [0001] This invention relates to stable crystals of sucralose having improved handling properties, and a method for making the crystals. BACKGROUND OF THE INVENTION [0002] Sucra lose, 4,1′,6′-trichloro-4,1′,6′-trideoxygalactosucrose, a sweetener with a sweetness intensity several hundred times that of sucrose, is made from sucrose by replacing the hydroxyl groups in the 4, 1′, and 6′ positions with chlorine. Synthesis of sucralose is technically challenging because of the need to selectively replace specific hydroxyl groups with chlorine atoms, while preserving other hydroxyl groups including a highly reactive primary hydroxyl group. Numerous approaches to this synthesis have been developed. See, e.g. U.S. Pat. Nos. 4,362,869, 4,826,962, 4,980,463, and 5,141,860, which are expressly incorporated herein by reference. [0003] Crystallization is widely used to purify and recover compounds, including, but not limited to, sugar, sucralose, and related substances. Cr...

AI Technical Summary

Benefits of technology

"The invention is a method for producing stable sucralose crystals from a sucralose solution. The method involves introducing a feed stream of sucralose solution into a system, allowing sucralose crystals to form continuously. The resulting output stream is then removed, with a part of it being recirculated back to the system. The recirculated part is separated from the output stream, resulting in stable sucralose crystals. The method is controlled so that the sucralose passes through the system at least four hours. The separated sucralose crystals are then dried at a temperature of about 85°F or below. The invention also includes stable sucralose crystals that have a plurality of crystalline sucralose domains and are generally tapered in shape."

Problems solved by technology

Synthesis of sucralose is technically challenging because of the need to selectively replace specific hydroxyl groups with chlorine atoms, while preserving other hydroxyl groups including a highly reactive primary hydroxyl group.

Typically, many such needles are broken, which produces undesirable dust.

Such crystalline sucralose has poor handling characteristics, including poor flow, which makes it difficult to incorporate into formulations with other ingredients.

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