Protein based excipient for active pharmaceutical ingredients

A formulation comprising:

• a whey protein based excipient obtained from a whey protein composition or a hydrolysate thereof which comprises whey protein monomers of at least 100 amino acids in length;
• and
• a Class II or Class IV active pharmaceutical ingredient (API) according to the biopharmaceutics classification system;
• wherein said whey protein based excipient and said API form a homogenous and amorphous solid dispersion wherein said whey protein based excipient and said API are both completely amorphous, as verified by X-ray powder diffraction (XRD) and form a completely homogenous mixture, as verified by differential scanning calorimetry (DSC), and
• wherein the mass ratio (w/w) of said API to said whey protein based excipient is between at least 10% API and at most 90% whey protein based excipient (10/90) to at most 40% API and at least 60% whey protein based excipient (40/60).