Solubilisation of hydrophilic drugs in oily formulations

Association of peptides with oil carriers can improve the delivery of these molecules by affording protection against intestinal proteases, improving stability in the presence of gut surfactants and altering cell permeability and lymphatic secretion. Intestinal delivery of calcitonin using an oil-based formulation is illustrated in the pig, and a new technology (‘Macrosol’) is described in which hydrophilic molecules are solubilised directly in oils in the absence of an aqueous phase. Presentation of macromolecules in this form can change the way in which they interact with cells, and give rise to new possibilities for drug delivery via the intestine.