Dirk Heidemann

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The rates of moisture sorption and the resultant effect on stability of a moisture-sensitive drug blended r formulated with different components are addressed. Total moisture increase was determined by weight gain, and change in mobile water level by water activity measurements. Equilibrium relative humidity is a useful tool in predicting the stability of a(More)
Theophylline, guaifenesin, and benzoic acid were determined by reversed-phase high-pressure liquid chromatography without interference from active and/or vehicle decomposition. A degradation product of sucrose, 5-hydroxymethylfurfural, can be identified and quantified in liquid samples simultaneously.
Buffered solid dosage forms containing aspirin, magnesium hydroxide, and aluminum hydroxide are blended with acidic ethanol to extract the aspirin and salicylic acid rapidly. The resulting preparation is then immediately injected onto a 4.6 mm x 3 cm 5 micron reverse-phase column. Aspirin and free salicylic acid are determined simultaneously. The run time(More)
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