How does product-handling influence its stability?
In a clinical setting, a drug product may be diluted and encounters different surface materials (such as tubings, infusion bags, pumps, closed system drug transfer devices) before it is finally administered to the patient.
Therefore, formulation development needs to assess the stability of a formulation after dilution as well as its compatibility with commonly used clinical diluents and clinical materials.
Such studies are crucial because dilution of excipients can lead to a loss of product stability and thus therapeutic efficacy. Also, adsorption of the drug substance to surface materials and variations in extractable volume can negatively impact dosing. Furthermore, the introduction of subvisible particles either by aggregation of the drug substance or via the surface materials needs to be investigated. In-use stability is usually done with a selection of the most promising drug product candidates using fresh as well as aged material to assess the stability up to 24 h.