A pharmaceutical composition containing a therapeutic protein which is particularly amenable to oral administration by providing stability in the gastrointestinal tract. Insoluble fibrils or aggregates of the therapeutic protein in the pharmaceutical composition are encapsulated in a lipidated glycosaminoglycan particle, coated with a multi-layer of lipids and lipid-glycosaminoglycan conjugates, or present as unencapsulated and uncoated insoluble fibrils or aggregates.
