Vacuum Contact Drying of Pharmaceutical Powders with and without agitation: A Comparison
The drying efficiency of vacuum contact drying of aspirin agglomerates and aspirin powder with and without agitation was compared using an agitated filter dryer (AFD). The aim of the study is to compare the drying efficiency and impact of vacuum contact drying with and without agitation of the samples under investigation. Operating conditions was at 15 wt. % initial moisture content, heating jacket temperature of 75 and agitation speed of 30 rpm. It was found that vacuum contact drying with agitation is more efficient in the drying of aspirin agglomerates and aspirin powder than vacuum contact drying without agitation. About 49% decrease in drying time was observed in the drying of aspirin agglomerates with agitation compared to without agitation and 64% decrease in the drying time of aspirin powder when agitation was applied, in contrast to without agitation. Thus, equilibrium moisture content was also reached in vacuum contact drying with agitation in a much faster rate than in vacuum contact drying without agitation at exactly same operating conditions.