Dionex is proud to announce a new method for improving the United States Pharmacopeia (USP) monograph assays for drug products containing either three or four active pharmaceutical ingredients (APIs) used to treat tuberculosis (TB). This new application, AN 257: HPLC Assay Method for Drug Products Containing Anti-Tuberculosis Active Pharmaceutical Ingredients, uses the hydrolytic-stability-enhanced Acclaim® PolarAdvantage II (PA2) column with an UltiMate® 3000 system to assay drug products using either a conventional HPLC approach or a time- and mobile-phase saving UHPLC approach. All APIs can be determined with one method rather than two, and in less time.

The two HPLC assay methods previously described in the USP monograph require two separate injections and use different mobile phases, requiring equilibration between tests. In comparison, this new single-injection method can determine all four anti-tuberculosis APIs commonly used to treat TB (isoniazid, pyrazinamide, rifampicin, and ethambutolare) in 10 minutes. The analysis of two representative drug products yielded acceptable percentage contents, as judged by the limits in the USP monograph. Further savings and waste reduction are possible with the UHPLC method that requires less than 2 minutes per injection.

This application and many other pharmaceutical analysis methods can be found at www.dionex.com under the Markets tab by clicking on Pharmaceuticals.

Dionex (NASDAQ:DNEX) is a global leader in the manufacturing and marketing of liquid chromatography and sample preparation systems, consumables, and software for chemical analysis. The company's systems are used worldwide in environmental analysis and by the life sciences, chemical, petrochemical, food and beverage, power generation, and electronics industries. Our expertise in applications and instrumentation helps analytical scientists to evaluate and develop pharmaceuticals, establish environmental regulations, and produce better industrial products.

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