Abstract: The present application relates to improved and effective purification processes and also relates to method of increasing the solubility of for GLP-1 analog and its derivatives particularly Liraglutide. The purification process of present application is advantageous not only in terms of providing the highly pure peptide chemically but also in terms of affording peptide drug substance which is having good physical stability even at a large scale during holding or in-use period, while making drug substance compatible for formulation.