Diphenhydramine tannate liquid and semi-solid compositions and methods of use

Abstract

Pharmaceutical compositions consisting of diphenhydramine tannate which are effective when administered for the symptomatic relief of sneezing, itchy, watery eyes, itchy nose or throat and runny nose due to hay fever (allergic rhinitis) or other respiratory allergies are disclosed.

Description

[0001] This is a continuation-in-part of U.S. patent application Ser. No. 10 / 119,285 filed Apr. 9, 2002 which claims the benefit of Provisional Patent Application Ser. No. 60 / 282,969 filed Apr. 10, 2001.FIELD OF INVENTION [0002] The invention relates to novel antihistaminic tannate compositions. The compositions contain as an essential ingredient diphenhydramine tannate. BACKGROUND OF THE INVENTION [0003] Tannins are water-soluble phenolic metabolites of plants with a molecular weight of 5-5000 Da. Physicochemically, tannins are complex polymers, which can be classified as two major types: the condensed tannins and hydrolyzable tannins. Hydrolyzable tannins or tannic acids are referenced in the various pharmacopeias and are composed of gallic acid or its condensation product ellagic acid esterified to the hydroxyl groups of glucose. Each hydrolyzable tannin molecule is usually composed of a core D-glucose and 6 to 9 galloyl groups. [0004] In nature, there is an abundance of mono and...

AI Technical Summary

Benefits of technology

[0013] The present invention relates to a therapeutic composition for symptomatic treatment of respiratory allergies in a warm-blooded animal where that composition comprises a pharmaceutically effective amount of diphenhydramine tannate of c

Problems solved by technology

It is typically produced from Turkish or Chinese nutgall and has a complex, non-uniform chemistry.

Diphenhydramine also possesses a pronounced tendency to induce sedation.

However, antihistamine tannate salts are heat sensitive and therefore undergo decomposition quite readily upon prolonged exposure to temperatures as low as 50 degrees C. In addition, the yield obtained is usually only about 70% and impurities including decomposition products and a significant amount of the volatile solvent used during preparation (up to about 5-10%) cannot be effectively removed.

This causes significant processing problems during manufacture of products containing tannate salts as active ingredients, and increases the likelihood that commercially available pharmaceutical products contain variable and in some instances, sub-therapeutic levels of said active drug substances creating dosing problems.

This approach results in a dosage form suffering from a number of shortcomings.

These include the use of expensive equipment and the time involved in freeze-drying.

This approach also suffers from batch to batch variability and all of the attendant disadvantages outlined above.

Further, the development of a suitable and effective freeze-drying process can be complicated.