| dc.description.abstract | According to the statistics, at least 193 tons of drugs are thrown away in Taiwan every year and antibiotics make up a large proportion. Among them, tetracycline is the second largest class of antibiotics in the world, and the most common veterinary drug. For this reason, the aim of this research is to recycle tetracycline hydrochloride (TCH), one of the antibiotics, from capsule wastes as a case study. Experiments include two parts: (1) solvent screening and selection for recrystallization of purchased TCH according to the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) guideline Q3C (R6) on impurities: Guideline for residual solvents, and (2) the results based on the first part were extended to recycle TCH from different brands of capsules (KINGDOM® and NOVABIOTIC®) in a 500 ml stirred tank scale. The effects of mixing, aging time, aging temperature, addition rates, and agitation rates on TCH recycling are studied. Solid-liquid extraction was applied to the capsules in methanol with an agitation rate of 300 rpm for 1.5 hours, and filtration by a 0.22 μm PVDF filter membrane. The addition of antisolvent, MTBE with an addition rate of 9.9 ml/min, with an agitation rate of 900 rpm, and aged for 2 hours at 25℃, then filtered through a 1μm alpha cotton cellulose filter paper to collect the solids. The recovery rates of TCH achieved 73.1%, and the HPLC assay achieved 99.2%. A novel, fast and simple operation, and reproducible recycling processes were carried out in this research. Most importantly, the original pure form of the active pharmaceutical ingredient (API) can be recovered directly instead of decomposing or transforming into some other components. | en_US |