Dressler D, et al. – This research was designed to examine the long–term stability of reconstituted botulinum toxin (BT) type A (BT–A) drugs in the hemidiaphragm assay (HDA), a high–quality BT potency test. This study allowed un–used reconstituted incobotulinumtoxinA (INCO) to be stored for further use and this could have a considerable impact on the costs of BT therapy. Further studies were needed to demonstrate sterility of the reconstituted BT drug beyond the so far reported 6 weeks.

• The authors reconstituted this incobotulinumtoxinA (INCO) and stored in at 4–8 °C, whilst at various points of time probes of it were taken and potency tested with the HDA.
• Throughout a period of 52.1 weeks, 18 measurements were performed.

• In the HDA, the paralysis time was 67.3 ± 5.2 min (min. 59 min, max. 76 min).
• They described the linear regression line by y = -0.0163x + 67.582.
• During the first 10 weeks (n = 11), the paralysis time measured was 67.5 ± 5.3 min, during the last 10 weeks (n = 7) 67.1 ± 4.9 min.
• As tested by the high quality HDA, reconstituted INCO did not show reduction of potency throughout 52 weeks.
• As per the outcomes, lack of complexing proteins did not de-stabilise INCO.