Stability of somatostatin in total parenteral nutrition

The stability of somatostatin, added to a total parenteral nutrition formula, in glass containers and in plastic ethylene vinyl acetate containers was investigated. The somatostatin concentration decreased immediately from 3 micrograms/ml to 0.3-0.6 micrograms/ml after addition to the emulsion. In spite of this rapid decrease, somatostatin concentrations remained stable with values of 0.4-0.7 micrograms/ml during the follow-up period (24 h). These findings could be explained assuming adsorption to the surface of the container.