Mcintyre Group, Ltd.

Thomas G Schoenberg

Richard John Otterson

Darrell J Zehner

Dennis Abbeduto

Improved liquid antimicrobial solutions useful as preservative additives to personal care preparations, particularly cosmetic formulations and the like, are provided which comprise 1,3-dimethylol-5,5-disubstituted hydantoin, liquid aromatic alcohol, and iodoalkynyl alkyl carbamate. A preferred antimicrobial solution can be prepared by producing the 1,3,dimethylol-5,5-disubstituted hydantoin in situ in the selected liquid aromatic alcohol and then adding to the resulting solution the previously prepared iodoalkynyl alkyl carbamate. The solutions are surprisingly water dispersible and display broad spectrum antimicrobial effectiveness, particularly antifungal effectiveness, at a relatively low usage concentration in a cosmetic medium.

Antimicrobial liquid preservative solutions and process for preparation

A method of preparing a formaldehyde substituted hydantoin in the form of a liquid antimicrobial preservative solution is disclosed. The inventive solution prepared by the disclosed method comprises a condensation product of a 5,5-disubstituted hydantoin and formaldehyde prepared in the presence of an antimicrobial liquid phenylic or benzylic alcohol. The inventive solution inhibits or retards microbial growth when an effective microbial inhibiting amount is subsequently added to a medium capable of supporting undesirable microbial growth. Preferably the inventive solution contains 1,3-dimethylol-5,5-dimethyl hydantoin prepared in the presence of phenoxyethanol and including an effective antimicrobial amount of at least one paraben preservative prepared by an embodiment of the disclosed method.

Antimicrobial solution of formaldehyde substituted hydantoin and process

A method of preparing an antimicrobial preservative system in a substantially anhydrous liquid form is disclosed. The antimicrobial preservative system inhibits or retards microbial growth when an effective antimicrobial amount is subsequently added to a medium capable of supporting undesirable microbial growth. More particularly, the preservative system comprises a condensation product of a 5,5-disubstituted hydantoin and formaldehyde prepared in the presence of a substantially anhydrous, water-miscible, solvent and an alkalizing agent. Also disclosed is a cold-stable, substantially anhydrous liquid preservative system comprising 1,3-dimethylol-5,5-dimethylhydantoin alone or in combination with an effective antimicrobial amount of at least one paraben preservative prepared by an embodiment of the disclosed method.

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Lemont, IL, United States of America

Thomas G Schoenberg