Storage conditions for serum deslorelin

The stability of a luteinizing hormone-releasing hormone (LHRH) analog in rat serum was studied under reproduced experimental analysis conditions. Serum samples of deslorelin [D-Trp6, Des-Gly, NH2(10)] LHRH ethylamide were exposed to multiple freeze-thaw cycles to determine the maximum number of cycles the serum sample can be exposed to without producing any quantitative changes in radioimmunoassay (RIA) measurements of deslorelin. A significant cycle effect was observed after completion of the sixth cycle. Serum samples were also stored at standardized -50 degrees C conditions for variable periods of time to determine the effects of acute and chronic storage time on deslorelin stability. Matched-pair t-test analysis showed no significant changes in deslorelin values as measured by RIA for a 3-week, 4-month, or 2-year storage period. The conditions in which the rat serum samples were stored prior to analytical analysis were sufficient to prevent detectable degradation of the deslorelin peptide.