Usually, there is a slight overfilling in small volume injectable drug products, especially for biological active ingredients, in order to guarantee the excess volume. In its actual FDA Guidance for Industry "Allowable Excess Volume and Labelled Vial Fill Size in Injectable Drug and Biological Products" finalised for 24 June 2015 the FDA clarifies its point of view and the corresponding requirements. The guidance for industry only refers to drugs in ampules or vials that are intended for injection. Other packaging types (such as prefilled syringes and intravenous infusion bags) or noninjectable products are not mentioned.
Injectable vial misuse, including unsafe handling and injection techniques, has led to more cases of vial contamination - especially in multiple-dose containers - and with that to an increased risk of bloodborne illness transmission between patients. According to the FDA inappropriate excess volume and labelled vial fill sizes are two factors that may contribute to this misuse.
With its recommendations in this guidance the FDA intends to prevent an overfilling of vials without sufficient reasons. The details of the final guidance for industry "Allowable Excess Volume and Labelled Vial Fill Size in Injectable Drug and Biological Products" were already commented in the news "New FDA Guidance to Avoid Overfill in Vials" on the draft of the document on 31 March 2014.