Pharmaceutical Composition Comprising a Radiolabeled GRPR Antagonist and a Surfactant

A pharmaceutical composition comprising

• a radiolabeled GRPR-antagonist of the following formula:
• MC-S-P
• wherein:
• M is a radiometal and C is a chelator which binds M;
• S is an optional spacer covalently linked between C and the N-terminal of P;
• P is a GRP receptor peptide antagonist of the general formula:
• Xaa1-Xaa2-Xaa3-Xaa4-Xaa5-Xaa6-Xaa7-Z;
• Xaa1 is not present or is selected from the group consisting of amino acid residues Asn, Thr, Phe, 3-(2-thienyl) alanine (Thi), 4-chlorophenylalanine (Cpa), α-naphthylalanine (α-Nal), β-naphthylalanine (β-Nal), 1,2,3,4-tetrahydronorharman-3-carboxylic acid (Tpi), Tyr, 3-iodo-tyrosine (o-l-Tyr), Trp and pentafluorophenylalanine (5-F-Phe) (all as L- or D-isomers);
• Xaa2 is GIn, Asn or His;
• Xaa3 is Trp or 1, 2, 3, 4-tetrahydronorharman-3-carboxylic acid (Tpi);
• Xaa4 is Ala, Ser or Val;
• Xaa5 is Val, Ser or Thr;
• Xaa6 is Gly, sarcosine (Sar), D-Ala, or β-Ala;
• Xaa7 is His or (3-methyl)histidine (3-Me)His;
• Z is selected from —NHOH, —NHNH2, —NH-alkyl, —N(alkyl)2, and —O-alkyl
• or Z is
• wherein X is NH (amide) or O (ester) and R1 and R2 are the same or different and selected from a proton, an optionally substituted alkyl, an optionally substituted alkyl ether, an aryl, an aryl ether or an alkyl-, halogen, hydroxyl or hydroxyalkyl substituted aryl or heteroaryl group;
• and,
• a surfactant comprising a compound having (i) a polyethylene glycol chain and (ii) a fatty acid ester.