“…Pharmacists who employed this technique have used strict aseptic technique, specialized decapping devices, and laminar airflow hoods. Some pharmacists also have required that medication withdrawn from a vial with its stopper removed be filtered through a 0.22 μm filter to further reduce the risk of microbial contamination [56]. Even with strict aseptic technique, there is a suggestion -but not clear evidence -of an increased risk of contamination [41].…”