The present invention provides a novel liquid composition suitable forin-situformation of a depot system to deliver a protein or peptide in a controlled manner. The composition of the present invention comprises: (a) a hydrophobic non-polymeric carrier material (b) a water miscible biocompatible organic solvent that dissolves the hydrophobic non-polymeric material (c) a protein or peptide covalently conjugated with one or more formulation performance-enhancing compounds. The present invention also provides a method of manufacturing and use of the composition thereof.本發明提供一種適合於原位儲庫系統之新穎液體組合物,以一控制方式傳輸一蛋白質或胜肽。本發明組合物包括:一疏水性、非聚合物載體材料;一與水互溶之生物相容性有機溶劑,溶解該疏水性、非聚合物材料;一蛋白質或胜肽,與一或多個配方效能促進化合物共價結合。本發明亦提供一種該組合物之製造及使用方法。