The present invention is a delivery system for sublingual and/or buccal delivery comprising at least one functional oil (i.e. acting as an oil delivery base)； at least one surfactant； and at least one pharmaceutically active agent. The invention also includes a method for treating diabetes, for regulating blood glucose levels and/or for treating hyperglycaemia by sublingual or buccal administration of the delivery system where the pharmaceutical agent is insulin and/or an insulin analogue or mimetic, and/or a glucagon-like peptide-1 agonist.
