The invention relates to a process for the preparation of injectable pharmaceutical compositions for the sustained release of somatostatin analogues and to pharmaceutical compositions prepared according to the process. In a preferred aspect the process comprises the steps of combining lanreotide acetate and acetic acid, lyophilizing the resulting mixture only once, and hydrating the lyophilizate. Acetic acid may be added to a desired pH during the final step of the process.本發明係關於一種製備持續釋放生長激素抑制素類似物之可注射醫藥組成物之方法，以及依照該方法製備的醫藥組成物。於該方法的一較佳態樣中，包含以下步驟：使乙酸蘭瑞肽(lanreotide)與乙酸結合、將獲得的混合物僅進行一次冷凍乾燥，並使該冷凍乾燥物水合。在該方法最後的步驟中，可以添加乙酸至達到所欲的pH。
