Storage conditions for serum deslorelin

The stability of a luteinizing hormone-releasing hormone (LHRH) analog in r at serum was studied under reproduced experimental analysis conditions. Ser um samples of deslorelin [D-Trp(6) Des-Gly, NH210] LHRH ethylamide were exp osed to multiple freeze-thaw cycles to determine the maximum number of cycl es the serum sample can be exposed to without producing any quantitative ch anges in radioimmunoassay (RIA) measurements of deslorelin. A significant c ycle effect was observed after completion of the sixth cycle. Serum samples were also stored at standardized -50 degrees C conditions for variable per iods of time to determine the effects of acute and chronic storage time on deslorelin stability. Matched-pair t-test analysis showed no significant ch anges in deslorelin values as measured by RIA for a 3-week, 4-month, or 2-y ear storage period. The conditions in which the rat serum samples were stor ed prior to analytical analysis were sufficient to prevent detectable degra dation of the deslorelin peptide.