Process for production of stabilized powdery secretin preparation by lyophilization

#This invention relates to a stabilized powdery secretin preparation and a process for the production thereof. More particularly, the invention relates to a stabilized powdery secretin preparation useful for therapeutic treatment, wherein the secretin is carried on an adequate amount of alanine serving as excipient and weighing material, and a process for the production thereof by lyophilization of an aqueous solution of secretin in the presence of the alanine.

#Secretin is one of the hormones present in digestive tracts and capable of stimulating excretion of enzyme-free pancreatic juice from pancreas and inhibiting gastrine-stimulated gastric secretion. Secretin is therefore useful for therapeutic treatment of diseases in digestive tracts and for diagnosis of disorders thereof.

#Secretin as is known is so unstable that it gradually loses its hormone activity even if kept at a low temperature such as -20.degree.C. Addition of cysteine hydrochloride to secretin was proposed in order to improve its temperature stability and a certain increase in its stability was thus attained. It was found however that the stabilized secretin preparation is still unstable and cannot stand for a prolonged period of storage at room temperature. It is thus necessary to keep the preparation in a refrigerator.

#An aqueous solution was prepared by dissolving under sterilization 2 grams of .alpha.-alanine and 5000 Crick, Harper and Raper units of secretin into 50 ml of a buffer solution of pH 4.5 containing 0.03 M citric and phosphoric acids. Each 0.5 ml aliquot of the resulting solution was lyophilized in an ampoule of 2 ml capacity and then sealed.

#An aqueous solution was prepared by dissolving under sterilization 3 grams of .beta.-alanine and 5000 Crick, Harper and Raper units of secretin into 50 ml of a 0.02 M tartaric acid buffer solution of pH 4.5. Each 0.5 ml aliquot of the resulting solution was lyophilized in an ampoule of 2 ml capacity and then sealed.

#An aqueous solution was prepared by dissolving under sterilization 1 gram of .alpha.-alanine, 1 gram of .beta.-alanine and 5000 Crick, Harper and Raper units of secretin into 50 ml of a 0.02 M citric acid buffer solution at pH 5.0. Each 0.5 ml aliquot of the resulting solution was lyophilized in an ampoule of 2 ml capacity and then sealed.