This page lists insulins according to their preservatives.All Lente family insulins Semilente, Lente and Ultralente can only use methylparaben as a preservative. All PZIs use only phenol. The mixed insulins use both Meta-cresol and phenol. However, with both the fast-acting analogs and the short-acting R/Neutral insulins, the decision to use only Meta-cresol or both Meta-cresol and phenol is made by the pharmaceutical company producing them. The Lilly and Sanofi-Aventis fast and short-acting insulins have only Meta-cresol as a preservative. Both Novo Nordisk and CP Pharma/Wockhardt use both Meta-cresol and phenol in theirs.
Since CP Pharma/Wockhardt produces the Insuvet line of bovine insulins for Schering-Plough, even though NOAH-UK has no excipient list for them, it is not unreasonable to assume that in the case of their Insuvet Neutral, it contains both Meta-cresol and phenol as does the Hypurin Bovine Neutral CP/Wockhardt produces. As only methylparaben can be used for Lente-family insulins and only phenol is used with Protamine Zinc insulins, they would, by default, be the preservatives present in Insuvet Lente and Insuvet Protamine Zinc.