Instability studies of porcine somatotropin in aqueous solutions and the possible reagents for its stabilization

The instability of porcine somatotropin (pST) in various solutions and poss ible stabilization of the hormone by sugars and mild detergents were studie d. Aggregation and decomposition of the hormone molecules in various pH sol utions and under presence of sugar or detergent were monitored by gel perme ation chromatography (GPC) or ultraviolet spectroscopy (UV). The pST is a v ery unstable hormone in an aqueous environment. It was found in this projec t that the peptide hormone underwent aggregation or decomposition quickly i n acidic and alkaline solutions but slowly in neutral pH solutions. High lo sses of PST monomers were seen in concentrated solutions of the hormone. On the other hand, PST monomers were stabilized to a certain degree in glucos e solutions and at a low concentration of urea. These results should facili tate the development of efficient controlled release systems which are esse ntial for commercializing porcine somatotropin.